To see the other types of publications on this topic, follow the link: Ultraviolet treatment.
Dissertations / Theses on the topic 'Ultraviolet treatment'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Ultraviolet treatment.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Holloway, Willie D. "Ultraviolet tunnel treatment as applied to table grapes /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1136079411&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text
2
Cilliers, Frans Pieter. "A biochemical study of the effect of ultraviolet treatment on bovine milk and Cheddar cheese." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97803.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2015.ENGLISH ABSTRACT: This study describes: 1. The evaluation of a novel, patented thin-film, turbulent-flow Ultravioletdisinfection system as an alternative processing method to thermal pasteurisationfor the disinfection of bovine milk. 2. The microbial, biochemical and sensory characterization of bovine milk treated by heat and Ultraviolet light and then used for the commercial production of Cheddarcheese. 3. The microbial, biochemical and sensory characterization of commercial Cheddarcheese produced from bovine milk treated by heat and Ultraviolet light.
AFRIKAANSE OPSOMMING: Hierdie studie beskryf: 1. Die evaluasie van ‘n unieke, gepatenteerde dun-film, turbulente vloeiUltravioletsisteem as ‘n alternatief vir termiese pasteurisasie vir die behandeling van beesmelk. 2. Die mikrobiologiese-, biochemiese- en sensoriese karakterisasie van beesmelkbehandel met hitte en Ultravioletlig gebruik vir kommersiële produksie van Cheddar kaas. 3. Die mikrobiologiese-, biochemiese- en sensoriese karakterisasie van kommersiëleCheddarkaas vervaardig van beesmelk wat behandel is met hitte en Ultravioletlig.
3
Puga, Gil Ursinio. "Ultraviolet Disinfection Pilot Study at the Fargo Wastewater Treatment Plant." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/28690.
Full textAbstract:
A pilot study was carried out at the Fargo wastewater treatment plant to determine the impacts that flow rate, water quality, and system fouling may have on the efficiency of UV disinfection. A second-order model successfully explained the results obtained with the collimated beam. The second-order model was used to study the impact of water quality and initial microorganism concentration on E. coli inactivation rates. Fouling material was mostly made of precipitated metal salts and its impact on UV intensity reduction was explained with the application of the Beer-Lambert law. E. coli inactivation in the pilot unit was found to be dependent on UVT, flow rate, and UV intensity. A first-order plug-flow model successfully explained the inactivation data obtained in the pilot unit. No significant seasonal water quality changes that may affect system operation were identified. However, UVT changes caused by storm events had short-term adverse impacts on system performance.
4
Mayor-Smith, Ian. "Polychromatic fluence : calculation and application in ultraviolet reactors for water treatment." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/44040.
Full textAbstract:
IIn recent decades the application of UV disinfection technology in water treatment has rapidly increased on a global scale, however important uncertainties remain regarding; the methods to achieve consistent and accurate measurement of polychromatic UV output, the fluence-response of microorganisms to UV wavelengths over the entire polychromatic lamp output range, and the optimal lamp conditions and compositions to optimise polychromatic UV disinfection performance. This research aimed to address each of these areas of uncertainty. First, limitations in the existing methods that are used for lamp output measurement were identified and quantified in terms of their potential to cause significant errors in polychromatic UV fluence calculation; solutions are proposed to overcome these limitations in future polychromatic fluence measurements. Next, a novel experimental apparatus was constructed, achieving the necessary spectral requirements to produce a high resolution action spectra for waterborne microorganisms over the 200-300 nm wavelength range. Application of this experimental setup to the comparison of the fluence-response of T1 and T1UV phage, common organisms used in UV reactor validation, identified important differences in UV sensitivity dependent on host selection, and high resolution action spectra were then produced for T1UV with two hosts over the full polychromatic UV range for the first time. Also, new viral surrogates were identified using a theoretical genomic model to predict their UV sensitivities, two of which were identified as having the potential to extend the upper UV fluence validation test limits. Finally, the production of a novel high pressure plasma discharge polychromatic lamp was achieved without the use of mercury, showing considerable potential for future applications.
5
Zeng, Minzhen. "Investigations of operating conditions to improve the UV transmittance in chemically enhanced primary treatment /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202009%20ZENG.
Full text
6
Komvuschara, Kanyarat. "UV disinfection in comparison with other small scale disinfection technologies for the treatment of domestic greywater." Thesis, University of Hertfordshire, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247322.
Full text
7
Mfa-Mezui, Antoine Aime. "The effect of ultraviolet-C treatment on the biochemical composition of beer." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20365.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2012.ENGLISH ABSTRACT: This study describes: · Development of analytical tools to investigate the light struck flavour (LSF) in beer by Gas chromatography mass spectrometry (GCMS) and by liquid chromatography mass spectrometry/mass spectrometry (LCMS/MS). Development of a high performance liquid chromatography (HPLC) method to analyse carbohydrates in beer. · The efficiency a pilot scale ultraviolet (UV-C) system at 254 nm to inactivate spoilage microorganisms spiked in commercial beer. Bacteria test were Lactobacillus brevis, Acetobacter pasteurianus and Saccharomyces cerevisiae · A pilot scale UV treatment of commercial and non-commercial lager beers at UV dosage of 1000 J/L. Following the UV treatment, the correlation between chemical analyses and sensory tests conducted by consumers’ tasters were investigated. · A pilot scale UV treatment of non-commercial beer brewed with reduced hops iso-α-acids (tetrahydro-iso-α-acids) at UV dosage of 1000 J/L. Sensory changes and chemical properties were investigated. · The development and optimisation of an UV light emitting diodes (UV-LED) bench scale apparatus. Chemical and microbiological tests were conducted to investigate the effect of UV-LEDs on beer at 250 nm and 275 nm wavelengths.
AFRIKAANSE OPSOMMING: Hierdie studie beskryf: · Die ontwikkeling van analitiese toerusting om die invloed van lig op die smaakontwikkeling in bier te bestudeer m.b.v gaschromatografie massa spektrometrie (GCMS) en vloeistofchromatografie massa spektrometrie/massa spektrometrie, asook die ontwikkeling van ‘n hoë druk vloeistofchromatografiese metode vir die analise van koolhidrate in bier. · Die doeltreffendheid van ‘n toetsskaal ultraviolet (UV-C) sisteem om die nadelige mikroorganismes waarmee die bier geïnnokuleer was, by 254 nm te inaktiveer.. Toetse is uitgevoer met die volgende bakterieë, Lactobacillus brevis, Acetobacter pasteuriants en Saccharomyces cerevisiae. · ‘n Toetsskaal UV behandeling van kommersiële en nie-kommersiële lager biere by ‘n UV dosering van 1000 J/L. Na UV behandeling is die verwantskap tussen chemiese analises en ‘n reeks sensoriese toetse deur vebruikers proeërs ondersoek.. · ‘n Toetsskaal UV behandeling van ‘n nie-kommersiële bier gebrou met verlaagde hops-iso-α-sure (tetrahidro-iso-α -sure) by UV dosering van 1000 J/L. Sensoriese veranderinge asook chemiese eienskappe is ondersoek. · Die ontwikkeling en optimalisering van ‘n UV-lig emissie diodes bankskaal apparaat. Chemiese en mikrobiologiese toetse is uitgevoer om die effek van UV lig op bier by 250 nm en 275 nm te ondersoek.
8
Primm, Aaron N. "Immunosuppression, inflammation, and skin cancer will eczema treatment enhance ultraviolet light-induced skin cancer? /." Connect to resource, 2006. http://hdl.handle.net/1811/6433.
Full textAbstract:
Thesis (Honors)--Ohio State University, 2006.Title from first page of PDF file. Document formatted into pages: contains 45 p.; also includes graphics. Includes bibliographical references (p. 41-45). Available online via Ohio State University's Knowledge Bank.
9
Bazri, Mohammad Mahdi. "Assimilable organic carbon formation during ultraviolet-hydrogen peroxide advanced oxidation treatment of surface water." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30062.
Full textAbstract:
Practice of UV/H₂O₂ advanced oxidation treatment has emerged as viable alternative for removing micro-pollutants and other organic contaminants from surface water. However, presence of natural organic matter (NOM) in water is problematic and hinders the efficacy of the treatment process. Indeed, NOM can undergo significant partial oxidation leading to generation of smaller more easily assimilable organic molecules (i.e., AOC). Earlier studies have found AOC as the potential cause of bacterial regrowth and other water health concerns thereof within the distribution system. Nonetheless, impact of UV/H₂O₂ process on biostability of downstream water has not gained much attention. However, a method recently developed by Hammes and Egli (2005) opened the opportunity for more accurate and relatively rapid quantification of the AOC. The main focus of this research was to modify and evaluate the protocol of Hammes and Egli (2005) for quantifying the biostability of water before and after UV/H₂O₂ process. More importantly, this research aimed to contribute substantially to the current understanding of easily assimilable organic molecules formation during UV/H₂O₂ treatment. As a result, different characterization techniques (e.g., HPSEC, UV₂₅₄, and TOC) were utilized to monitor transformation of NOM and to study the relationships among different NOM characteristics (e.g., molecular size distribution, UV₂₅₄, and AOC). Considering the concerns associated with NOM (especially when oxidation is applied in the treatment train), elimination of NOM ahead of the oxidation process can potentially increase the UV/H₂O₂ treatment efficacy as well as the finished water quality. Moreover, as the regulations become more stringent, many utilities hope to comply with them by retrofitting existing facilities and avoiding the construction of new ones. Thus, this research also focused to investigate the impact of a pre-treatment process such as coagulation to eliminate NOM prior to UV/H₂O₂ treatment. Using coagulation as pretreatment ahead of UV/H₂O₂ will be potentially of interest for those utilities that are currently applying coagulation and hope to comply with new regulations by minimum capital investment. More importantly, this would be beneficial because of the need to improve process efficacy and also final water quality and the reduced formation of disinfection by-products (DBPs) within the distribution system.
10
Simons, Richard Mark. "Developments in fluence rate modelling for ultraviolet light emitting diode based water treatment reactors." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/45351.
Full textAbstract:
Ultraviolet-C light emitting diodes (UV-C LEDs) are a promising technology for water disinfection. Over the last decade UV-C LEDs have shown dramatic improvements in output power, efficiency, lifetime, and cost. The low-voltage power supply and effective point source geometry of LED light sources allows for new applications and designs. Mercury gas discharge lamps have been used in UV disinfection for several decades, and as a result the industry has developed around the limited specifications of these lamps, such as their size and shape, high power requirements, and mercury content. The increased design freedom offered by LED sources is expected to revolutionise the UV disinfection industry. A model for the optical (fluence rate) distribution within a UV photoreactor was developed to match the freedoms afforded by the use of LED sources. The model development focused on design flexibility with regard to the shape of the reactor body to allow for the accurate modelling of unusual designs. Particular attention was paid to the modelling of internal reflections within the reactor. A Monte Carlo method was selected, where general solutions may be implemented to specific conditions within an arbitrary reactor design. The model focussed on the effects of optical design and did not include fluid dynamics simulations. A series of batch reactors, from 100 – 7500 mL in volume, were modelled for a range of internal reflectivity conditions, from wholly absorptive to specular or diffuse reflectivity. The model produced a 3D representation of the fluence rate distribution within each reactor; this distribution could be evaluated qualitatively to inform future reactor designs. The specific required inactivation energy (SRIE) was defined to allow for the quantitative comparison of different reactors. It was determined that the reactor designs with the highest efficacy have diffusely reflective internal surfaces: the scattering of radiation by diffuse surfaces increases the fluence rate uniformity, which is important for efficient disinfection. The parameter space available for investigation is vast; it was therefore not possible to find a globally optimised solution. However, variation across three parameters showed a broad range of near-optimum designs which resulted in a comparable disinfection performance. This suggests that relative improvements that would result from a global optimisation may be small. A cylindrical reactor of internal depth 90 mm and diameter 119 mm, with Lambertian diffusely reflective internal surface, illuminated by a single LED source (of arbitrary optical power) could achieve an SRIE of 6.56 mJ mL-1 for a treatment water of 90 % transmittance. For an LED source of 100 mW and peak emission 254 nm, this corresponds to a treatment time of 66 s for the 1000 mL volume of the proposed reactor, under a static batch treatment regime. This predicted performance of this device is suitable for application in home-scale point of use water disinfection.
11
Arjmandi, Parvin Arjmandi. "MULTI-OBJECTIVE OPTIMIZATION OF CORE WATER TREATMENT PROCESSES INCORPORATING ULTRAVIOLET AND FLUORESCENCE SPECTROSCOPIC MEASUREMENTS." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1501345847002254.
Full text
12
Uhlin, Fredrik. "Haemodialysis Treatment Monitored On-line by Ultra Violet Absorbance." Doctoral thesis, Linköping : Linköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7987.
Full text
13
Riley, Scott. "Measuring Viability of the Red-Tide Dinoflagellate Lingulodinium polyedra Following Treatment with Ultraviolet (UV) Light." NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/4.
Full textAbstract:
Harmful algae blooms (HABs) have caused millions dollars in annual losses to the aquaculture industry, inhibited beach recreation, and have threatened marine and human health. HABs and red tides can develop suddenly and their frequency, geographic range, and intensity have increased over the past decade. A possible source for spreading and seeding new areas expanding the geographic range of HABs is ballast water. The process of ballast water discharge has been identified as a primary vector for the translocation of non-indigenous species (NIS) and invasive species. National and international efforts are currently underway to address the impact of NIS and invasive species. Policy is being developed detailing stringent rules to kill, remove, or otherwise inactive organisms in ballast water prior to or upon discharge. Currently, vendors are developing technologies to treat ballast water and U.S. and international facilities are testing these technologies to verify their efficacy. Ultraviolet (UV) radiation is commonly employed in ballast water treatment technologies. Previous studies have shown that UV light is effective for disinfecting drinking water, but the response of non-pathogenic and marine organisms is largely unknown.
The purpose of this research was to measure the viability of the durable red-tide forming dinoflagellate, Lingulodinium polyedra following UV treatment. Two methods were used to measure the viability signal; manual epifluorescence microscopy with correlated viability stains and Pulse Amplitude Modulated (PAM) fluorometry to measure the physiological state of the organism following UV treatment. The number of cysts was also enumerated. The results showed that there was a significant decrease in the number of living L. polyedra cells following a UV treatment of more than 100 mWs cm-2. The results also have showed a significant increase in the number of L. polyedra cysts following UV treatment as low as 50 mWs cm-2.
14
Gautam, Dibash. "Use of Dean flow Ultraviolet Reactors For Cold Pasteurization of Tender Coconut Water." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/2002.
Full textAbstract:
The natural water inside green coconuts is regarded as a healthy drink due to the elements of nutritional and therapeutic value. Since there is chance of contamination of tender coconut water (TCW) with psychrophilic microbes during extraction from its hard shell if stored at 4 ºC, thermal pasteurization is currently practiced. However, the thermal treatment of TCW causes a rise in off flavors and loss of the vital nutrients. To solve this problem, a non-thermal pasteurization technology is desirable. The goal of this research was to assess the antimicrobial effectiveness of ultraviolet light C (UVC) as non-thermal pasteurization of TCW and evaluation of physico-chemical and sensory quality of the treated TCW in comparison to the fresh TCW. A dean flow ultraviolet reactor was used with wavelength of 254 nm at the residence time of 14.0 seconds. The independent variables were three Reynold numbers (Re1 = 198.8, Re2 = 397.7 and Re3 =596.4) and two different diameters of transparent PFA tubes (3.2 mm and 1.6 mm). TCW was inoculated with cultures of Escherichia coli and Listeria monocytogenes separately up to 8 log10 CFU/mL and inactivation by cold pasteurization was evaluated with number of log reduction of each bacteria. Physico-chemical properties like total solid content (TSS) and pH were analyzed throughout the storage period of four weeks. The sensorial quality, flavor and color of the coconut water was also evaluated by a panel of 30 people to compare the organoleptic characteristics of UVC treated samples with untreated fresh coconut water. In case of Escherichia coli W1485, UVC treatment gave the log reduction of 5.27 and 4.74 log10 CFU/mL in coconut water for 1.6 mm and 3.2 mm ID reactors, respectively. Whereas the reduction of Listeria monocytogenes were 4.18 and 2.96 log10 CFU/mL for 1.6 mm and 3.2 mm ID reactors, respectively. In case of both the bacteria, as the tube size increased, microbial reduction decreased; and as the Reynold number increased, microbial reduction also increased except where there was an interaction effect. The change of tube diameters gave significantly different inactivation for both test bacteria at all Reynolds number except at Re2 and Re3 in case of Escherichia coli. The different levels of Reynolds number were not significantly variant when compared with consecutive levels, but Re1 to Re3 were significantly different for both test bacteria. The physico-chemical and sensorial changes of cold pasteurized TCW weres not significantly different compared to the fresh TCW, providing the conformity of retention of natural and organoleptic characteristics of TCW.
15
Cates, Stephanie. "Materials modification strategies to improve praseodymium-doped visible-to-ultraviolet upconversion systems for environmental applications." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54907.
Full textAbstract:
UV radiation is utilized in a number of environmental technologies, most notably for the disinfection of water, air, and surfaces through the use of UVC fluorescent lamps. Recently, our group developed a luminescent material that could emit germicidal UVC simply by irradiating it with a household fluorescent lamp, thus introducing a new type of antimicrobial surface powered by low-intensity visible light. The materials were doped with praseodymium ions (Pr3+) which have the unique capability of converting visible light to higher energy UV using an optical mechanism called upconversion. While visible-to-UV upconversion materials appeared promising for environmental application—particularly because solar irradiation could be used for their activation—their practical application was thwarted by low light conversion efficiencies. Herein we discuss the pursuit of new material forms and modifications designed to improve the efficiency of Pr3+-based upconversion systems. These enabled successful enhancement of antimicrobial activity and led to a proof of concept for upconversion-sensitized TiO2 photocatalysis. Correlations between material properties and optical behavior will be presented, followed by commentary on how these strategies might be used to further advance upconversion systems toward environmental application.
16
Musskaya, O. N., A. I. Kulak, V. K. Krutsko, S. A. Ulasevich, L. A. Lesnikovich, Леонід Федорович Суходуб, Леонид Федорович Суходуб, and Leonid Fedorovych Sukhodub. "The Influence of Ultrasound and Ultraviolet Irradiation on the Nanocomposite Calcium Phosphate-Polymeric Gel." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35469.
Full textAbstract:
An influence of high-intensive ultrasound and ultraviolet (UV) irradiation on the nanocomposite calcium
phosphate-polymeric gels has been investigated. The action of UV light leads to a significant increase
in shear stress and viscosity of hydroxyapatite (HA) / polyvinyl alcohol (PVA) gel while HA / sodium carboxymethyl
cellulose (Na-CMC) gel is insensitive to the UV action. Ultrasonic treatment of HA / PVA gel
plays an important role only at small shear rates. UV treatment of HA / Na-CMC gel has no effect on its
structure and can be used for low temperature UV sterilization.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35469
17
Howell, Anne C. "Effects of antioxidant vitamin treatment on UV-irradiated cells." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941360.
Full textAbstract:
Ultraviolet (UV) radiation damages both eukaryotic and prokaryotic cells by causing the formation of free radicals which damage cell membranes and DNA. Antioxidant vitamins have been shown to protect cells from UV-induced damage by scavenging free radicals. The protection of skin and its normal flora is necessary for the health of individuals in resisting diseases caused by microorganisms and delaying the long-term damage caused by UV radiation.This research investigated the effects of the antioxidants vitamin A and ascorbic acid, as well as UV-irradiation on both prokaryotic (Staphylococcus epidermidis) cells and eukaryotic (human fibroblast skin) cells. This information is important in determining the effects of vitamin treatment on skin and its normal flora.Results indicate that ascorbic acid is rapidly (within six hours) degraded after being dissolved in water or medium. Treatment of cells with ascorbic acid must take into account this rapid degradation. S.epidermidis cells were protected from UV-induced damage by treatment with ascorbic acid but were more sensitive to UV-irradiation when treated with vitamin A. Human fibroblast cells treated with ascorbic acid did not exhibit morphological changes when compared to untreated cells.Department of Biology
18
CAMACHO, PAULO R. R. "Desinfeccao de efluentes de sistemas de tratamento de esgotos sanitarios por meio da radiacao ultravioleta." reponame:Repositório Institucional do IPEN, 1995. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10428.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:38:36Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:04:36Z (GMT). No. of bitstreams: 1 06057.pdf: 4829282 bytes, checksum: d92eb047d0390013a61d21a5e1144641 (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
19
Armioun, Shaghayegh. "Using Ultrasound as a Pretreatment Method for Ultraviolet Disinfection of Wastewaters." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20263.
Full textAbstract:
In this study, the effects of neutral particles addition on the breakage of wastewater flocs toimprove the efficiency of sonication pretreatment for UV disinfection process have been studied.Kaolin particles as a potentially useful material that is neutral, natural and cheap were added towastewater samples prior to sonication. Results obtained in this study indicated that hard andsmall kaolin particles do not have any significant effect on the particle breakage efficiency byultrasound. The addition of kaolin particles did not significantly increase the cavitation activity(as characterized by potassium iodide actinometry) either. These findings contradict earlierreports that neutral particles can act as nucleation sites and hence enhance cavitation intensity. Inthis work, sonication of wastewater samples for 60s in the absence of kaolin particles resulted inan approximately one log decrease in the number of surviving bacteria colonies at the tailinglevel and 1.4 log units increase at the initial slope of coliform removal in UV dose responsecurve, however addition of kaolin particles prior sonication did not significantly affect the UVdose response curve .The results presented in this study should be treated as preliminary andfurther detailed investigations are needed to better evaluate this issue.
20
Monyethabeng, Moneah Mmabatho. "Effect of ultraviolet treatment on shelf life, various spoilage microorganisms and the physicochemical characteristics of rooibos iced tea." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2021.
Full textAbstract:
Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2015.Rooibos iced tea (RIT), as one of the products of Rooibos is fast becoming very popular as a beverage in society due to the benefits of the phenolic compounds that are associated with this herbal tea. Some of the commercially available products have been found to contain, if any, lower contents of the major phenolic compounds, namely aspalathin and its oxidation products, iso-orientin and orientin. Their presence is considered as indicators of a good quality product. The purpose of this study was to investigate the effect of ultraviolet-C (UV-C) light as an alternative treatment to heat treatment on the shelf life, pH, phenolic composition, colour and microorganisms associated with Rooibos. Two formulations of RIT were used in order to determine the efficacy of the UV-C on the shelf life whilst three formulations were used for the physicochemical analysis. Only one formulation was used for inoculation with three spoilage bacteria, yeast and mould spoilage microorganisms namely; Escherichia coli K12, Staphylococcus aureus, Salmonella sp., Saccharomyces cerevisiae and Cladosporium sp. The UV-C dosages of 0, 918, 1 836, 2 754 and 3 672 J.l -1 were used to treat the RIT using a pilot-scale UV-C system with a turbulent flow at a constant flow rate of 4000 l.hr-1 . A log count of 4 log10 was considered the limit for the spoilage growth since it is the average log10 afternormal pasteurisation. The use of UV-C treatment was found to have significantly (p1) effect on the overall colour difference of the RIT in formulations A, B, and C. All the spoilage microorganisms were significantly reduced by UV-C dosage to less than 4 log10 except the Cladosporium sp. The S. cerevisiae was the most sensitive microorganism whilst Cladosporium sp. was the most resistant. The effect of UV-C on the spoilage microorganism followed the sequence: S. cerevisiae>Salmonella sp.>S. aureus>E. coli K12>Cladosporium sp. This study indicated that microbiological reduction was achieved as a function of increasing UV-C dosage. In order to achieve the highest log10 reduction, the highest UV-C dosage of 3 672 J.l-1 may be used. However, the dosage may need to be increased in order to achieve the desired results in the treatment of Cladosporium sp. It can thus be concluded from the above investigations that UV-C dosage treatment of 3 672 J.l-1 is optimum in the non-thermal treatment of RIT
South African Association for Food Science & Technology Cape Peninsula University of Technology Bursary
21
Tremocoldi, Maria Augusta [UNESP]. "Atividade antioxidante, compostos fenólicos totais e cor em abacate ‘hass’ submetido a diferentes tratamentos físicos." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/93461.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:26:39Z (GMT). No. of bitstreams: 0
Previous issue date: 2011-03-03Bitstream added on 2014-06-13T20:34:24Z : No. of bitstreams: 1
tremocoldi_ma_me_botfca.pdf: 616438 bytes, checksum: 67f1da03c193fb8aca4f0e4cbb1ebdac (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O presente trabalho teve por objetivo determinar a atividade antioxidante, compostos fenólicos totais e cor em abacate ‘Hass’ submetido ao tratamento térmico, radiação gama e ultravioleta. Após a colheita, os frutos foram selecionados para tornar o lote homogêneo. Foi realizada a caracterização do fruto verde e amadurecido quanto a acidez titulável, pH, umidade, teor de lipídios, cinzas (minerais), proteína (nitrogênio bruto), açúcar total e coloração. Foram realizados 3 experimentos com frutos recém colhidos. Experimento I: imersão dos frutos em água a 45ºC por 5, 10, 15 e 20 minutos; Experimento II: radiação gama nas doses 0,2; 0,4; 0,6 e 1,0kGy e Experimento III: radiação ultravioleta (UVC) por 5, 10, 15 e 20 minutos. Após os tratamentos, os frutos foram armazenados em temperatura ambiente (21ºC±1 e 70±5% de UR) e refrigerado (10ºC±1 e 90±5% de UR). Os frutos foram analisados quanto à capacidade antioxidante pelo método DPPH e compostos fenólicos totais aos 0, 3, 9 e 12 dias. A coloração foi avaliada aos 0, 3, 6, 9, 12 e 15 dias. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 1% de probabilidade. Nas condições em que os experimentos foram realizados, pode-se concluir que os frutos do tratamento testemunha e mantidos sob refrigeração apresentaram maior capacidade antioxidante e teor de compostos fenólicos totais ao longo do período de armazenamento; o tratamento térmico por 5 e 10 minutos foi efetivo na manutenção da capacidade antioxidante e dos compostos fenólicos; a dose de 0,6kGy não foi efetiva na manutenção da capacidade antioxidante; a radiação ultravioleta (UV-C) não manteve a capacidade antioxidante dos frutos, no entanto ocasionou aumento na quantidade de compostos fenólicos; o tratamento térmico e a radiação ultravioleta não afetaram a coloração da polpa
This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' submitted to heat treatment, gamma and ultraviolet radiation. After harvest, fruits were selected to make the homogeneous portion. The characterization was performed of the green fruit and mature as acidity, pH, moisture, lipids, ash (minerals), protein (nitrogen gross), total sugar and coloring. 3 experiments were performed with freshly harvested fruits. Experiment I: immersion of fruits in water at 45 ° C for 5, 10, 15 and 20 minutes; Experiment II: gamma radiation doses 0.2, 0.4, 0.6 and 1.0 kGy and Experiment III: ultraviolet radiation (UV-C) for 5, 10, 15 and 20 minutes. After treatments, fruits were stored at room temperature (21±1ºC and 70±5% HR) and refrigeration (10ºC±1 and 90±5% HR). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The color was measured at 0, 3, 6, 9, 12 and 15 days. Data were subjected to analysis of variance and mean comparison using Tukey’s test at 1% probability. In conditions where the experiments were performed, one can conclude that the fruits of control treatment and kept under refrigeration had higher antioxidant capacity and content of phenolic compounds during the storage period, the heat treatment for 5 and 10 minutes was effective the maintenance of antioxidant capacity and phenolic compounds, the dose of 0.6 kGy was not effective in maintenance the antioxidant capacity, ultraviolet radiation (UV-C) did not maintain the antioxidant capacity of fruits, however caused an increase in the content of phenolic compounds, heat treatment and ultraviolet radiation did not affect the pulp color
22
McGlade, Jacqueline Patricia. "Suppression of the asthmatic phenotype in mice by UVB irradiation." University of Western Australia. School of Paediatrics and Child Health, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0086.
Full textAbstract:
Background: Exposure of skin to UVB radiation (290-320 nm) modulates the immune system, with most studies showing a suppression of Th1-driven immune responses. Investigations into the effects of UVB exposure on allergic respiratory responses have been limited. This study investigated the systemic effects of UVB on Th2-associated immune responses using two different murine models of allergic respiratory inflammation. The mechanism of immune regulation was also examined. Methods and Results: Two murine models of asthma were used: the papain model and the ovalbumin (OVA) model using papain and OVA, respectively, as the allergens. In the papain model, C57BL/6, histamine receptor-1 knockout (H1RKO) and histamine receptor-2 knockout (H2RKO) mice were exposed to a single 4 kJ/m2 dose of UVB (twice a minimal oedemal dose) on shaved dorsal skin three days prior to intranasal sensitisation with papain, a cysteine protease homologue of the house dust mite (Dermatophagoides pteronyssinus) allergen Der p 1. Sensitisation and boost each consisted of five daily intranasal doses of 1 µg papain whilst the challenge consisted of three daily intranasal doses of 100 µg papain. Asthmatic symptoms were assessed 24 h after the final challenge dose. H1RKO mice demonstrated enhanced papain-specific inflammatory responses in the lung-draining lymph nodes (LDLNs) whilst the responses of H2RKO mice closely mimicked those of C57BL/6 mice. UVB irradiation three days before sensitisation reduced in vitro papain-specific proliferation of LDLN cells from C57BL/6 and H1RKO mice but not H2RKO mice 24 h after challenge. The regulatory effect of UVB was transferred by adoptive transfer of 5 x 106 unfractionated LDLN cells from UVB-irradiated, papain-sensitised and -challenged C57BL/6 and H1RKO donor mice into naïve recipients of the corresponding strain that were ii subsequently sensitised and challenged with papain. Additionally, UVB exposure suppressed papain-induced IL-5 and IL-10 production in vitro by LDLN cells from H1RKO mice but not from C57BL/6 mice or H2RKO mice. The results of this study demonstrate systemic immunomodulation of responses to intranasally delivered antigen by UVB irradiation and the induction of regulatory cells in the LDLN following UVB exposure. Furthermore, these results implicate a role for the H2R in UVB-induced suppression of antigen-specific responses in the draining lymph nodes.
23
Liu, Xingjian. "Membrane Electrochemical Treatment of Landfill Leachate: Processes, Performance and Challenges." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/105173.
Full textAbstract:
Landfilling is the most common approach to dispose of municipal solid wastes but inevitably leads to leachate formation. Persistent UV quenching substances (UVQS) in landfill leachate can affect the effectiveness of UV disinfection in municipal wastewater treatment systems when leachate co-treatment is applied. Membrane electrochemical reactor (MER) treatment was investigated to reduce the UV quenching capability and simultaneously recover resources in the leachate as an effective onsite pre-treatment. Ion-selective membranes were used in this MER to create two different conditions: a low-pH anolyte for organic oxidation and a high-pH catholyte for ammonia recovery. The MER achieved significantly higher removals of both dissolved organic carbon and UV254nm absorbance than membrane-less electrochemical treatment. The MER was able to remove a large percentage of total nitrogen from the leachate while recovering about half of the influent ammonia in the catholyte with less specific energy consumption. The second study coupled MER with Fenton oxidation through providing synergistic benefits with the low solution pH, reduced organics, and ammonia removal. This two-stage coupled system reduced the more leachate COD than the standalone Fenton process treating raw leachate. Also, the usage of chemicals as Fenton reagents has been greatly reduced: FeSO4 and H2O2 by 39%, H2SO4 by 100%, and NaOH by 55%. Consequently, the sludge production was reduced by 51% in weight and 12% in volume. Despite electricity consumption by the MER, the coupled system cost $4.76 per m3 leachate less than the standalone Fenton treatment. More notably, direct Fenton oxidation removed only 21% of ammonia; in comparison, the MER-Fenton system removed ammonia by 98% with the possibility for recovery at a rate of 30.6 -55.2 kg N m-3 reactor d-1. Those results demonstrated that coupling MER with the Fenton process could mitigate some inherent drawbacks of Fenton oxidation such as ineffective ammonia removal, high acid and chemical reagents dose requirements, and a large amount of sludge generation. The third study investigated the formation of total halogenated organics (DBP) and the associated toxicity as the side effect of leachate treatment in the MER. Compared to the 4538±100 µg L-1 from the control membrane-less electrochemical oxidation reactor, the amount of DBP generated in the MER only accounted for 19.1±4.5 % after the same treatment period. The total toxicity value (26.6 ×10-3 ) was low for MER effluent, only 15.1% of that in the control group. Both high pH and high ammonia concentration introduced more DBP mass and toxicity production after MER treatment. DBP concentrations were shown to increase with applied current density and possible temperature raise. With 67.5% of DBP mass concentration and 74.4% of the additive toxicity removal, the granular activated carbon (GAC) electrode system was shown more effective than GAC adsorption alone in remediating DBP harmful effects. This dissertation introduced MER as a promising technology for the treatment of leachate through performance demonstration, process integration and by-product remediation.Doctor of Philosophy
Municipal solid waste is often disposed of in landfills because of the most economics and convenience. However, one of the most challenging problems is the leachate formation and treatment. In the US, leachate is currently often diluted in domestic wastewater treatment systems; meanwhile, the persistent contaminants in landfill leachate can lower the effectiveness of UV disinfection and result in high cost and permit violation. In this study, the membrane electrochemical reactor (MER) using electricity as the driving force was applied to solve the issue and simultaneously recover valuable resources in the leachate. Membranes as a barrier for selective ions were used in this MER to create two different conditions with different purposes: a low-pH anolyte for organic oxidation and a high-pH catholyte for ammonia recovery. The MER achieved significantly higher contaminants removals than membrane-less electrochemical treatment. The second study coupled MER with one of the established advanced oxidation processes, also known as Fenton oxidation through providing mutual benefits with the low solution pH, reduced organics, and ammonia removal/recovery. This two-stage coupled system reduced the leachate contaminants effectively towards the direct discharge standard. In addition, the usage of chemical reagents, as well as the amount of process residual, has significantly been reduced. The third study investigated the formation of by-products as the side effect of leachate treatment in the MER. Compared to the membrane-less reactor, the undesirable by-products generated in the MER only accounted for one fifth after the same treatment period. A granular activated carbon electrode system was shown effective in remediating the harmful effects. This dissertation introduced MER as a promising technology for the treatment of leachate as one of the toughest wastewaters.
24
Nguyen, Ha Thi. "Effect of transmittance and suspended soils on the efficacy of UV disinfection of bacterial contaminants in water." Title page, contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09AS/09ash111.pdf.
Full textAbstract:
Errata pasted onto front end-paper. Bibliography: leaves 113-120. To obtain robust and quantitative data on the influence of UV absorption and suspended solids on UV disinfection an experimental study using commercial disinfection technology was undertaken.
25
ANIPSITAKIS, GEORGIOS P. "COBALT/PEROXYMONOSULFATE AND RELATED OXIDIZING REAGENTS FOR WATER TREATMENT." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1130533674.
Full text
26
Bergman, Gerald Rae. "Evaluation of exposure to optical radiation used in diagnostic and treatment in medicine and dentistry." Connect to full-text via OhioLINK ETD Center, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=mco1095952844.
Full textAbstract:
Thesis (M.S.)--Medical College of Ohio, 2004."In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Farhang Akbar. Includes abstract. Document formatted into pages: iv, 75 p. Title from title page of PDF document. Includes bibliographical references (p. 58-68).
27
Groenewald, W. H., P. A. Gouws, F. P. Cilliers, and R. C. Witthuhn. "The use of ultraviolet radiation as a nonthermal treatment for the inactivation of alicyclobacillus acidoterrestris spores in water, wash water from a fruit processing plant and grape juice concentrate." Journal for New Generation Sciences, Vol 11, Issue 2: Central University of Technology, Free State, Bloemfontein, 2013. http://hdl.handle.net/11462/634.
Full textAbstract:
Published ArticleAlicyclobacillus acidoterrestris is a non-pathogenic, spore-forming bacterium that can survive the commercial pasteurisation processes commonly used during fruit juice production. Surviving bacterial endospores germinate, grow and cause spoilage of high acid food products. Fruit juices can be treated using ultraviolet light (UV-C) with a wavelength of 254 nm, which has a germicidal effect against micro-organisms. In this study, A. acidoterrestris was inoculated into water, used wash water from a fruit processing plant and grape juice concentrate. Ultraviolet dosage levels (J L-1) of 0, 61, 122, 183, 244, 305 and 367 J L-1 were applied using a novel UV-C turbulent flow system. The UV treatment method was shown to reliably achieve in excess of a 4 log10 reduction (99.99%) per 0.5 kJ L-1 of UV-C dosage in all the liquids inoculated with A. acidoterrestris. The applied novel UV technology could serve as an alternative to thermal treatments of fruit juices for the inactivation of Alicyclobacillus spores as well as in the treatment of contaminated wash water used in fruit processing.
28
Tapia, Tlatelpa Tecilli. "Optoelectronic optimization of photocatalytic processes for wastewater treatment." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667685.
Full textAbstract:
Water pollution is an alarming problem that endangers the health of all living beings. The textile industry is listed as one of the most contaminating industries, since in order to carry out its dyeing and finishing processes, it requires a large amount of water resources; by decades, this industry has used Advanced Oxidation Processes (AOPs), since they have several advantages (e. g. destruction of toxic substances, reduction of heavy metals, allowing their use in conjunction with other processes, among others). Among the AOPs, heterogeneous photocatalysis stands out for its high efficiency for the removal of contaminants, including azo dyes.
In order to perform a photocatalytic process, it is necessary to have a photoreactor, which will require a photocatalyst and at least one light source that activates the catalyst. This type of photoreactors can present several problems, such as the use of high cost photocatalysts, the generation of toxic byproducts in some low photocatalysts, the high electrical consumption caused by the use of traditional lighting sources and even difficulties with the geometry of the photoreactors.
Hence the scientific community has tried to optimize the photocatalytic processes, some scientists have worked in the generation of new photocatalysts to be able to use them in wavelengths generated by low cost lighting sources (e. g. visible light), nevertheless, which in many times it increases the price of the photocatalyst. Another approach is to reduce electricity consumption by opting for the replacement of traditional lamps with low consumption lighting, for example, LED lighting; However, this substitution is currently done arbitrarily, so sometimes some authors doubt the ability to use these sources in this type of process. Moreover, when trying to improve the lighting sources, the photoreactor can be altered, so it is important to take into account its characteristics in order to achieve a significant improvement.
This thesis focuses on an optoelectronic optimization to improve the efficiency of the lighting sources used in photocatalytic reactors. For this, a methodology has been generated to calculate LED arrays using uniform irradiance models, this irradiance must be homogeneous, with enough energy to photoactivate the catalyst with the aim to replace the traditional lamps, avoiding the chemical alteration of the photocatalysts; Likewise, a photocatalytic reactor has been designed and implemented on a laboratory scale with ultraviolet illumination adjusted to its characteristics (i.e. geometry, dimensions, among others) to work with a low cost photocatalyst (TiO2) in the decolorization of wastewater with textile dyes. Finally, in-situ monitoring has been designed and implemented in order to analyze the decolorization of textile water, this type of monitoring avoids the collection of water samples during the process, without altering the geometry of the reactor or reducing the volume of treated water in the reactor.La contaminación del agua es un problema alarmante que pone en peligro la salud de todos los seres vivos. La industria textil está catalogada como una de las industrias más contaminantes, puesto que para realizar sus procesos de teñido y acabado requieren de una gran cantidad de recursos hídricos; desde hace décadas esta industria ha usado los Procesos de Oxidación Avanzada (AOPs) al presentar diversas ventajas (e. g. destrucción de sustancias tóxicas, reducción de metales pesados, permitir su uso en conjunto con otros procesos, entre otros). Entre los AOPs, sobresale la fotocatálisis heterogénea, por su alta eficiencia para la remoción de contaminantes, incluidos los colorantes azoicos. Para realizar un proceso fotocatalítico, es necesario tener un fotorreactor, el cual requerirá de un fotocatalizador y al menos una fuente de iluminación que active el catalizador. Este tipo de fotorreactores pueden presentar diversos problemas, tales como, el uso fotocatalizadores de alto costo, la generación de subproductos tóxicos en algunos fotocatalizadores de bajo, el alto consumo eléctrico causado por la utilización de fuentes tradicionales de iluminación e incluso dificultades con la geometría de los fotorreactores. Por lo tanto la comunidad científica ha intentado optimizar los procesos fotocatalíticos, algunos científicos han trabajado en la generación de nuevos fotocatalizadores para poder utilizarlos en longitudes de onda generada por fuentes de iluminación de bajo coste (e. g. luz visible), no obstante, lo que en muchas ocasiones incrementa el precio del fotocatalizador. Otro enfoque se encuentra en la reducción del consumo eléctrico optando por la sustitución de las lámparas tradicionales por iluminación de bajo consumo, por ejemplo, iluminación LED; sin embargo, actualmente esta sustitución se realiza de manera arbitraria, por lo que en ocasiones algunos autores dudan de la capacidad de utilizar estas fuentes en este tipo de procesos. Además al intentar mejorar las fuentes de iluminación puede alterarse el fotorreactor, por lo que es importante tomar en consideración sus características para lograr una mejora significativa. Esta tesis se enfoca en una optimización optoelectrónica para mejorar la eficiencia de las fuentes de iluminación utilizadas en reactores fotocatalíticos. Para ello se ha generado una metodología para calcular arreglos de LEDs utilizando modelos de irradiancia uniforme, esta irradiancia debe ser homogénea, con energía suficiente para fotoactivar el catalizador y sustituir las lámparas tradicionales, evitando la alteración química de los fotocatalizadores; asimismo, se ha diseñado e implementado un reactor fotocatalítico a escala de laboratorio con iluminación ultravioleta ajustada a sus características (geometría, dimensiones, entre otros) para trabajar con un fotocatalizador de bajo coste (TiO2) en la decoloración de agua con colorantes textiles. Para finalizar se ha diseñado e implementado un sistema de monitorización in-situ para la decoloración de aguas teñidas, este tipo de monitorización evita la toma de muestras de durante el proceso, sin alterar la geometría del reactor ni disminuir el volumen de agua tratada del reactor.
29
Fernandes, Ligia Gonzaga. "Caracterização clínico-histopatológica e avaliação terapêutica de fotoprotetor nas queilites actínicas." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/23/23139/tde-28032014-161323/.
Full textAbstract:
A queilite actínica (QA) é uma doença que afeta a semimucosa labial, principalmente inferior, causada pela exposição crônica à radiação solar ultravioleta (UV). É uma lesão potencialmente maligna extremamente frequente e considerada precursora da grande maioria dos cânceres de lábio, em pacientes não fumantes. A etiologia da QA permite medidas preventivas de fotoproteção solar, porém grande parte da população não as utiliza em função do desconhecimento do risco potencial e falta de informação. De outro lado se acredita que o dano causado ao lábio é irreversível e que a adoção de medidas fotoprotetoras apenas limita o dano e que quadros de displasia intensa deveriam ser tratados de forma cirúrgica radical. O objetivo principal deste estudo foi avaliar o efeito do uso de fotoprotetor labial, na forma de bastão, sobre parâmetros clínicos de severidade e grau de displasia histológica por meio de acompanhamento clínico e investigações microscópicas sucessivas. Foram selecionados pacientes que procuraram a Clínica de Diagnóstico Oral da FOUSP e apresentavam sinais clínicos sugestivos de QA. Os pacientes foram orientados quanto às condições de participação no trabalho de pesquisa e assinaram termo de consentimento livre e esclarecido. Após a confirmação de QA, em sequência ao procedimento de biópsia e análise histopatológica, os pacientes foram efetivamente incluídos no grupo de pesquisa. O local da biópsia incisional foi escolhido a partir do exame clínico e teste do azul de toluidina. Os pacientes foram orientados quanto ao uso do fotoprotetor e de barreiras físicas, sendo acompanhados a cada três meses para reavaliação clínica e reforço das medidas de fotoproteção. Após pelo menos seis meses de uso do fotoprotetor uma nova biópsia incisional foi realizada para avaliação histopatológica do quadro. Os espécimes de biópsia dos dois momentos foram analisados inicialmente por diversos patologistas (via rotina clínica-laboratório) e posteriormente por uma única patologista, mais especializada nessa área, cega em relação aos resultados anteriores. Vinte pacientes compuseram a casuística do trabalho, 12 homens e 8 mulheres, com idade média de 63 anos. De acordo com a análise histopatológica realizada via rotina do laboratório de patologia cirúrgica, dos 20 pacientes, dez apresentaram melhora das displasias e do quadro clínico; quatro permaneceram com as mesmas displasias, porém com melhora do quadro clínico; seis apresentaram piora do quadro histológico, porém houve melhora do quadro clínico em quatro deles. A análise realizada pela única patologista produziu resultados bastante diversos, registrando piora dos graus de displasia do primeiro para o segundo momento. Concluímos que a utilização do fotoprotetor produz melhora dos sinais clínicos exibidos pelos pacientes com QA e que os parâmetros clínicos não correspondem aos sinais de displasia histopatológica. Trata-se de doença ainda pouco reconhecida e valorizada tanto pela população quanto pelos profissionais da área de saúde com responsabilidade sobre essa área anatômica e estudos adicionais são requeridos para melhor compreensão da doença, normalização dos critérios de displasia microscópica e estabelecimento de características preditivas em relação à evolução carcinomatosa da doença.Actinic cheilitis (AC) is an injury that mainly affects the lower lip vermilion, and it is caused by chronic exposure to ultraviolet light. It is a very frequent potentially malignant disorder and it is considered the precursor of most lip cancers, in non-smoker patients. The AC etiology provides preventive measures of sun light protection, but most people do not use it because are unaware of the potential risks and lacking knowledge. On the other hand it is believed that the damaged caused to the lip is irreversible and the introduction of photoprotective measures just contain the damage and cases of severe dysplasia should be treated with radical surgery. The main purpose of this study was to evaluate the use of sunscreen lip balm in stick form, under clinical parameters of severity and degree of histological dysplasia by clinical follow-up and sequential microscopic researches. Patients selected were those who sought Clínica de Diagnóstico Oral in FOUSP and presented suggested signs of AC were selected. They were informed about the research terms of participation as well as signed a free and informed consent term. After confirm the diagnosis of AC with biopsy procedure and histopathological analysis, patients were included in the research group. The incisional biopsy site was selected by clinical exam and toluidine blue test. Patients were instructed about the use of sunscreen lip balm and physical protection, all of them had follow up appointments every three months to clinical evaluation and reinforcement of the use the use of lip sunscreen. After at least six months of lip sunscreen use, a new incisional biopsy was performed for histopathological evaluation. The biopsy specimens of the two procedures were initially analyzed by several pathologists (via laboratory routine) and later by a single blinded pathologist, more specialized in this field. Twenty patients were included in the sample of the study, 12 men and 8 women with a mean age of 63 years. According to histopathological analysis by laboratory routine, ten out of the twenty patients showed improvement in dysplasia and clinical signs; four remained with the same dysplasias, but with improvement of clinical signs; six had worsening results in histopathological analysis, however four of them presented improvement of clinical signs. The analysis conducted by the single pathologist produced very different results, registering worsening degrees of dysplasia from the first to the second procedure. In conclusion the use of sunscreen lip balm produces improvement of clinical signs on the patients with AC as well as the clinical parameters do not match with the signs of histopathological dysplasia. It is a poorly recognized and undervalued disease by both population and healthy professionals with responsibility for this anatomic area. Additional studies are required for better understanding of the disease, standardization of the criteria of microscopic dysplasia and establishment of predictive features to the progression of carcinoma.
30
Tremocoldi, Maria Augusta 1983. "Atividade antioxidante, compostos fenólicos totais e cor em abacate 'hass' submetido a diferentes tratamentos físicos /." Botucatu : [s.n.], 2011. http://hdl.handle.net/11449/93461.
Full textAbstract:
Orientador: Rogério Lopes VieitesBanca: Erica Regina Daiuto
Banca: Severino Matias de Alencar
Resumo: O presente trabalho teve por objetivo determinar a atividade antioxidante, compostos fenólicos totais e cor em abacate 'Hass' submetido ao tratamento térmico, radiação gama e ultravioleta. Após a colheita, os frutos foram selecionados para tornar o lote homogêneo. Foi realizada a caracterização do fruto verde e amadurecido quanto a acidez titulável, pH, umidade, teor de lipídios, cinzas (minerais), proteína (nitrogênio bruto), açúcar total e coloração. Foram realizados 3 experimentos com frutos recém colhidos. Experimento I: imersão dos frutos em água a 45ºC por 5, 10, 15 e 20 minutos; Experimento II: radiação gama nas doses 0,2; 0,4; 0,6 e 1,0kGy e Experimento III: radiação ultravioleta (UVC) por 5, 10, 15 e 20 minutos. Após os tratamentos, os frutos foram armazenados em temperatura ambiente (21ºC±1 e 70±5% de UR) e refrigerado (10ºC±1 e 90±5% de UR). Os frutos foram analisados quanto à capacidade antioxidante pelo método DPPH e compostos fenólicos totais aos 0, 3, 9 e 12 dias. A coloração foi avaliada aos 0, 3, 6, 9, 12 e 15 dias. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 1% de probabilidade. Nas condições em que os experimentos foram realizados, pode-se concluir que os frutos do tratamento testemunha e mantidos sob refrigeração apresentaram maior capacidade antioxidante e teor de compostos fenólicos totais ao longo do período de armazenamento; o tratamento térmico por 5 e 10 minutos foi efetivo na manutenção da capacidade antioxidante e dos compostos fenólicos; a dose de 0,6kGy não foi efetiva na manutenção da capacidade antioxidante; a radiação ultravioleta (UV-C) não manteve a capacidade antioxidante dos frutos, no entanto ocasionou aumento na quantidade de compostos fenólicos; o tratamento térmico e a radiação ultravioleta não afetaram a coloração da polpa
Abstract: This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' submitted to heat treatment, gamma and ultraviolet radiation. After harvest, fruits were selected to make the homogeneous portion. The characterization was performed of the green fruit and mature as acidity, pH, moisture, lipids, ash (minerals), protein (nitrogen gross), total sugar and coloring. 3 experiments were performed with freshly harvested fruits. Experiment I: immersion of fruits in water at 45 ° C for 5, 10, 15 and 20 minutes; Experiment II: gamma radiation doses 0.2, 0.4, 0.6 and 1.0 kGy and Experiment III: ultraviolet radiation (UV-C) for 5, 10, 15 and 20 minutes. After treatments, fruits were stored at room temperature (21±1ºC and 70±5% HR) and refrigeration (10ºC±1 and 90±5% HR). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The color was measured at 0, 3, 6, 9, 12 and 15 days. Data were subjected to analysis of variance and mean comparison using Tukey's test at 1% probability. In conditions where the experiments were performed, one can conclude that the fruits of control treatment and kept under refrigeration had higher antioxidant capacity and content of phenolic compounds during the storage period, the heat treatment for 5 and 10 minutes was effective the maintenance of antioxidant capacity and phenolic compounds, the dose of 0.6 kGy was not effective in maintenance the antioxidant capacity, ultraviolet radiation (UV-C) did not maintain the antioxidant capacity of fruits, however caused an increase in the content of phenolic compounds, heat treatment and ultraviolet radiation did not affect the pulp color
Mestre
31
Adityosulindro, Sandyanto. "Activation of homogeneous and heterogeneous Fenton processes by ultrasound and ultraviolet/visible irradiations for the removal of ibuprofen in water." Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/17913/7/aditosulindro-sandyanto.pdf.
Full textAbstract:
Due to booming consumption and only partial removal by conventional water treatment processes, ibuprofen, a non-steroidal anti-inflammatory drug, has been detected in water resources, raising increasing concerns for possible environmental and health impact. On the other hand, advanced oxidation processes (AOPs), among which Fenton reaction, have shown successful results forremoval of various organic compounds. Traditionally based on the use of hydrogen peroxide and ferrous ions in solution, large-scale application of this AOP is still limited by narrow pH window (2 to 4) and uneasy recovery of iron catalyst. This work investigated Fenton-based oxidation of ibuprofen, and reaction activation by ultrasound (US) irradiation and ultraviolet/visible light (UV/Vis) so as to lower the required concentration of dissolved iron catalyst or improve the activity of heterogeneous counterparts. To that purpose, the efficacy of individual homogeneous AOPs (sonolysis, photolysis, ultrasound/H2O2, light/H2O2, Fenton oxidation) was evaluated first, varying operating parameters such as light wavelength and ultrasound frequency. Then, their two-by-two and overall combinations (sonophotolysis, sono-Fenton, photo-Fenton and sono-photo-Fenton oxidation) were examined with emphasis on the identification of synergistic effects. In particular, combined US/Fenton and Vis/Fenton oxidation were found more effective than the sum of individualprocesses due to sono- and photo-regeneration of ferrous ions. These results also served as a reference for the assessment of heterogeneous systems. Among tested solids, iron-containing zeolite (Fe-ZSM5 type) was shown to be a promising catalyst for peroxide oxidation of ibuprofen due to high efficiency at natural pH and low iron leaching. However, in this case, no more than additive effects was observed between ultrasound/light irradiation and heterogeneous Fenton oxidation. Beside pollutant and Total Organic Carbon conversion, main degradation products were monitored for different processes and some plausible degradation pathways were proposed. Water matrix impact was also addressed using wastewater plant effluent, which resulted into hindered performance of all oxidation processes either due to alkaline buffer or light attenuation effect.
32
Cheung, Chi-shing, and 張志成. "Economic valuation of UV disinfection in Hong Kong sewage." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31255802.
Full text
33
Pires, Marco Roberto. "Desinfecção de esgotos com radiação ultravioleta : influencia da qualidade do efluente e da fotorreativação." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258116.
Full textAbstract:
Orientador: Jose Euclides Stipp PaternianiTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil
Made available in DSpace on 2018-08-02T03:02:10Z (GMT). No. of bitstreams: 1 Pires_MarcoRoberto_D.pdf: 5271302 bytes, checksum: 360fb9a15e870769155cec24f76d1dab (MD5) Previous issue date: 2002
Resumo: Desinfecção de esgotos com radiação ultravioleta vem sendo utilizado, principalmente, em países europeus e nos EUA. A fotorreativação dos microrganismos tem sido avaliada para determinar seu grau de interferência na desinfecção. Este trabalho teve como objetivo avaliar a radiação ultravioleta para diferentes qualidades de efluentes e estudar a fotorreativação. Foram utilizados dois reatores diferentes, sendo um com lâmpadas emersas e outro imersa. Os reatores foram testados em seis efluentes diferentes para quatro vazões diferentes para cada reator. Os coliformes totais e fecais foram analisados para avaliar a eficiência dos reatores. Ensaios de fotorreativação em condições controladas foram realizadas. De forma geral, o Reator I foi mais eficiente que o Reator TI, e a qualidade do efluente muitas vezes foi mais importante que a dose aplicada como apresentada no Ponto de Coleta 3 para coliformes fecais, em que a inativação foi maior para a vazão 4 (com menor tempo de exposição à luz) em vez de ocorrer para a vazão 1 (com maior tempo de exposição). Doses de radiação ultravioleta mais altas implicam em valores iniciais e finais de fotorreativação menores, porém para atingir o valor máximo necessita de mais tempo. Quanto maior a dose de radiação ultravioleta aplicada menor é o grau de fotorreativação; os coliformes totais tem melhor correlação para análises desta natureza quanto comparado com a E.co/i
Abstract: Disinfection of effluents with ultraviolet radiation has been used in Europeans countries and United States. The photoreactivation of microorganism have been estimated to determine the influence on the disinfection. The objective of this work had to evaluate the ultraviolet disinfection to different qualities of effluent and photoreactivation. Two different kinds of reactors were used in experimental analyzed. The reactors were tested to six different effluents for four flows. Total and fecal coliforms were analyzed to estimate the efficiency of reactors. Assays of photoreactivation were analyzed in controlled conditions. In most of case, the Reactor I was more efficient than Reactor II, and effluent quality was more important than the dose uv applied. Dose uv higher imply in initial and final values of lower photoreactivation. The total coliforms have better correlation than E.coli
Doutorado
Saneamento e Ambiente
Doutor em Engenharia Civil
34
Pasqualini, Liana Notari. "Estudo da oxidação de matéria orgânica de lixiviados de aterro sanitário por meio de tratamento com ozônio, peróxido de hidrogênio e radiação ultravioleta." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-06012011-161404/.
Full textAbstract:
Aterro sanitário é uma forma de destinação final de resíduos sólidos que gera lixiviado durante e após sua operação. O lixiviado é um líquido de elevada carga orgânica e poder poluidor. A presente pesquisa objetivou estudar a remoção da matéria orgânica presente em lixiviado de aterro sanitário bruto ou pré-tratado por air-stripping por meio de processos oxidativos avançados. Avaliou-se a influência do pré-tratamento na eficiência da remoção de matéria orgânica, a possibilidade do uso do conceito de número médio de oxidação do carbono como indicativo de oxidação e a ocorrência de processos sinérgicos na remoção dos parâmetros DQO, COT e cor proveniente da aplicação combinada de oxidantes. Os tratamentos propostos foram: ozônio apenas, ozônio/peróxido de hidrogênio e peróxido de hidrogênio/radiação ultravioleta. As doses de ozônio variaram entre 0,5 e 6 g/L. As doses de peróxido de hidrogênio variaram entre 0,2 e 7,2 g/L. Os tempos de contato de radiação ultravioleta variaram entre 40 e 200 minutos. O pré-tratamento por air-stripping, que visava à remoção de amônia, reduzia carga orgânica e a cor do lixiviado. A eficiência de remoção da DQO e COT foi baixa para todos os tratamentos propostos, alcançando valor máximo de 44%. As baixas eficiências podem ser decorrentes das interferências causadas por alcalinidade, nitrogênio amoniacal e sólidos fixos. O tratamento baseado em ozônio apenas apresentou as maiores eficiências de remoção de matéria orgânica. A remoção de cor foi elevada em todos os tratamentos, e os melhores resultados foram no tratamento baseado em ozônio/peróxido de hidrogênio. O pré-tratamento não alterou significativamente a oxidação da matéria orgânica. O conceito de número médio de oxidação do carbono não foi adequado para a indicação do processo oxidativo. A limitação do uso desse conceito está relacionada, provavelmente, à presença de DQO referente a substâncias inorgânicas, compostos nitrogenados e clorados. O efeito sinérgico do uso combinado de oxidantes não é dominante para a remoção da DQO e COT, e é em se tratando da remoção de cor.Sanitary landfills are a method for solid waste disposal that generates leachate when operating and after their closure. Leachate is a pollutant liquid with a high concentration of organic constituents. The aim of this study was the application of advanced oxidative processes for organic matter removal from raw and pre-treated leachate by air-stripping. This research evaluated the influence of pre-treatment on the organic matter removal efficiency; the possibility of using the concept of mean oxidation number of carbon, as indicative of organic matter oxidation; and the occurrence of synergic processes in the removal of COD, TOC and color, when combined oxidants were used. The proposed treatments were ozone only, ozone/hydrogen peroxide and hydrogen peroxide/ultraviolet radiation. Ozone concentrations varied from 0.5 to 6 g/L. Hydrogen peroxide concentrations varied from 0.2 to 7.2 g/L. Ultraviolet radiation contact time were between 40 and 200 minutes. Air-stripping pre-treatment, which aimed ammonia removal, caused organic and color reduction. The removal efficiency of COD and TOC was low for all treatments, reaching a maximum of 44%. The low efficiencies may result from interference caused by alkalinity, ammonia nitrogen and fixed solids. When ozone only was used, the highest organic matter removal efficiencies were achieved. Color removal was high for all the systems, and the best option for its removal was ozone/hydrogen peroxide system. The pre-treatment did not improve significantly the organic matter oxidation. The concept of mean oxidation number of carbon was not appropriate as indicator of oxidation process. The limitation of this concept is probably related to the presence of the inorganic COD, nitrogen and chlorine compounds. The synergic effect of combined oxidants was only dominant for color removal, which was not observed for COD and TOC removal.
35
Reygadas, Robles Gil Fermin. "User Compliance, Field Efficacy, and Greenhouse Gas Emissions of an Ultraviolet Water Disinfection System and other Drinking Water Treatment Alternatives for Rural Households in Mexico." Thesis, University of California, Berkeley, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3685996.
Full textAbstract:
Many households in developing countries rely on contaminated and untreated drinking water sources, contributing to gastrointestinal illness and other health risks. Even piped water quality is often unreliable because of poorly-maintained treatment or distribution systems. Household water treatment (HWT) systems aim to enable users to treat their water at the point of use, making it safe to drink. While some HWT options have been successful in improving health in developing countries, low adoption and sustained use outside pilot projects and epidemiological trials remains one of the current challenges with this approach. Furthermore, Quantitative Microbiological Risk Assessment models predict that the health benefits from water quality interventions drop significantly with even occasional consumption of contaminated water. Therefore, to be effective, HWT options need to achieve high user compliance rates and provide safe water reliably.
I begin my thesis with an interdisciplinary analysis of the field of water, health, and development, followed by a description of my research study site. Using an interdisciplinary research approach, grounded in the local context, I led the development of an ultraviolet (UV) water disinfection system for rural households. This included an iterative process of design and field tests to create a user-friendly system and laboratory research to improve the performance of the technology. I also collaborated with a non-profit organization based in Mexico in the design of an implementation program to support the adoption and consistent use of the UV system.
Then I present the design and application of a stepped-wedge cluster randomized trial in rural Mexico to evaluate compliance with the implementation program and field efficacy of the UV system. I developed a framework that disaggregates and measures the components of compliance from initial adoption of a safe water practice to exclusive consumption of safe water. I applied this framework to measure compliance across intervention and control groups and to test if additional program components that improve convenience to users can be a cost-effective approach to increase compliance. I present evidence that the implementation program significantly improved compliance with the habit of consuming safe water, when compared to the practice of purchasing water bottled in reusable 20 L containers in the control group. The additional program components proved to be a cost-effective strategy to increase compliance immediately post-intervention, but their impact degraded with time. By analyzing results across different compliance components, I find limitations of the current HWT approach. I present the rational for pilot testing strategies outside the current HWT paradigm, such as expanding a narrow focus on drinking water to making all domestic water safe to drink or switching from a product-based to a service delivery model.
As a second component of the randomized trial, I present a series of controlled comparisons to evaluate the field efficacy of the UV system using E. coli as a fecal contamination indicator in drinking water. I use an as-treated-analysis to isolate the impact of the system and contrast these results with an impact evaluation of the implementation program led by a research colleague. I also created a drinking water reliability framework to compare potential contamination impacts from different household water management practices and a logistic regression model to assess household risk factors for post-UV-treatment contamination. I show that treating water with the UV system and storing it in 20 L narrow-necked containers, allowed households to significantly improve their drinking water quality and gain access to a more reliable source of safe water.
In the final chapter I investigate the greenhouse gas (GHG) emissions associated with the use of HWT technologies in Mexico. I do that by carrying out a literature review of existing studies assessing energy use of water treatment technologies; using secondary data to perform a life cycle assessment (LCA) capturing the embedded CO2 equivalent emissions of individual HWT products; and developing model to calculate a metric of GHG emissions per volume of water used representative of the HWT sector in Mexico. Filtration, ozone, and UV disinfection technologies resulted in similar LCA emissions, while reverse osmosis had emissions five times higher than the average of the rest. I also find GHG emissions of HWT to be 30 times lower than water bottled in 20 L reusable containers. In a context in which mortgage institutions have created green credit mechanisms, this result is useful for expanding financing options for HWT products, which are often more cost-effective than bottled water, but require a higher capital investment. (Abstract shortened by UMI.)
36
Oliveira, Clélia Aparecida da Silva 1972. "Tratamento de corante têxtil por eletrólise, fotólise e fotocatálise utilizando LED UV = Treatment of textile dye by electrolytic, photolytic and photocatalytic processes." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267750.
Full textAbstract:
Orientador: Peterson Bueno de MoraesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
Made available in DSpace on 2018-08-23T06:55:03Z (GMT). No. of bitstreams: 1 Oliveira_CleliaAparecidadaSilva_M.pdf: 1434373 bytes, checksum: 2411a1ce9b13fbe4e8f7d778c6dfd3ea (MD5) Previous issue date: 2013
Resumo: A indústria têxtil gera elevados volumes de efluentes com alta carga orgânica e compostos recalcitrantes, os quais são tratados por sistemas baseados em processos físicos, químicos e biológicos convencionais. Entretanto, o caráter não destrutivo dos tratamentos convencionais representa um sério problema no setor. Nos últimos 20 anos, os Processos Oxidativos Avançados (POA) têm estado em evidência devido à sua capacidade em degradar inúmeros compostos orgânicos contidos em águas e efluentes. Uma grande quantidade de trabalhos utilizando luz UV a partir de lâmpadas de vapor de mercúrio tem resultado em elevada eficiência de degradação de substratos recalcitrantes incluindo efluentes têxteis; entretanto, demandam elevado consumo de energia elétrica, encarecendo o tratamento. Em contrapartida, o surgimento de Diodos Emissores de Luz Ultravioleta (LED UV) abre novas fronteiras de aplicação no campo de tratamento de águas residuárias, quanto a custo, operacionalidade e tamanho dos sistemas. Nesse trabalho estudou-se a degradação de um efluente têxtil simulado contendo o corante Remazol Azul Brilhante (C.I. Reactive Blue 19) através de processos eletroquímicos e fotoeletroquímicos que utilizam LED UV, utilizando-se dois reatores: um operando em batelada contendo o fotocatalisador TiO2 e o outro, em fluxo, contendo um cátodo (tela cilíndrica de aço-inoxidável), um tubo de quartzo contendo os LED UV e o Anodo Dimensionalmente Estável (ADE 70%TiO2/30%RuO2). Os resultados demonstraram que, no reator de bancada, a eficiência de remoção de cor foi de 100% para concentração inicial de 50 mg L-1 do corante, em 24 horas de tratamento. No reator em fluxo, utilizando Na2SO4 como eletrólito, o processo eletrolítico resultou em eficiência de 65%; o fotoeletrocatalítico, em 68%, operando a 750 L h-1 e em 57,3 mA cm-2. Quando foi utilizado o eletrólito NaCl, obteve-se remoção de 100% da cor em 5 minutos de tratamento a 750 L h-1, independente da concentração inicial do corante utilizada (50 mg L-1 ou 100 mg L-1), da concentração do eletrólito (0,05 M ou 0,1 M), da densidade de corrente (14,3 mA cm-2 , 28,7 mA cm-2 ou 57,3 mA cm-2) e do processo utilizado
Abstract: The textile industry generates large amount of wastewater containing significant organic load and recalcitrant compounds, which in most cases are treated by conventional systems involving physical, chemical and biological processes, the latter represented mainly by activated-sludge treatment. However, the non-destructive profile of conventional treatments is a serious problem for textile-based industry. Over the past 20 years, the study of Advanced Oxidation Processes (AOP) has been carried out due to its high capacity degradation of numerous organic pollutants contained in waters and wastewaters. Research using UV light from mercury vapor lamps usually has resulted in high efficiency degradation of recalcitrant substrates including textile effluents but requires high electrical power consumption besides other drawbacks. In contrast, the emergence of Ultraviolet Light Emitting Diodes (UV LED) opens new perspectives for application on wastewater treatment, concerning efficiency, footprint and costs of the systems. In this work we studied the degradation of a simulated wastewater containing a textile dye, Remazol Brilliant Blue (C.I. Reactive Blue 19) through electrochemical and photoelectrochemical processes using UV LED as ultraviolet radiation source. The experimental apparatus consisted of two systems: the first, a bench-scale reactor containing TiO2 photocatalyst (P25 DEGUSSA) in solution, and another pilot-scale system operated in batch recirculation mode composed of an tubular stainless-steel screen cathode, a quartz tube containing the UV LED and a oxide-coated titanium anode (DSA©30%TiO2/70%RuO2). The results showed total decolorization of a solution containing 50 mg L-1 of RB in 24-hour treatment in the bench-scale reactor. Tests on flow reactor using Na2SO4 as supporting electrolyte resulted in 65% of color removal using electrolytic process and 68% for photoelectrocatalytic process operating at 750 L h-1 and 57.3 mA cm-2. In experiments using the electrolyte NaCl it was obtained 100% in the color degradation within 5 minutes of treatment at 750 L h-1, regardless of the: initial concentration of dye used (50 mg L-1; 100 mg L-1), concentration of the electrolyte (0.05 M; 0.1 M) and current density value (14.3; 28.7; 57.3 mA cm-2)
Mestrado
Tecnologia e Inovação
Mestra em Tecnologia
37
SILVA, Ivaldo Jos? da. "Educa??o ambiental e o tratamento de ?gua: uso do sistema de tratamento de ?gua baseado em ultravioleta em C?mpus do Instituto Federal do Maranh?o e sua rela??o com a constru??o de conhecimentos." Universidade Federal Rural do Rio de Janeiro, 2013. https://tede.ufrrj.br/jspui/handle/jspui/2535.
Full textAbstract:
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-29T17:27:43Z
No. of bitstreams: 1
2013 - Ivaldo Jos? da Silva.pdf: 36618657 bytes, checksum: 428b35f4aa0bf23daa7adf9b14b4e7ef (MD5)Made available in DSpace on 2018-11-29T17:27:43Z (GMT). No. of bitstreams: 1 2013 - Ivaldo Jos? da Silva.pdf: 36618657 bytes, checksum: 428b35f4aa0bf23daa7adf9b14b4e7ef (MD5) Previous issue date: 2013-03-21
Research in Environmental Education Criticizes aims to construct and reflective critique of knowledge allowing individuals greater contextualisation-environmental relations and consequent changes, in attitudes towards collective transformation of reality. The municipality of Z? Doca, regional pole of Turi, located east of the State of Maranh?o, in the Northeast region near the border with the State of Par?, is responsibility to articulate educational actions, political and economic, social and environmental development of over 17 other municipalities in the region. It was found that municipalities the environmental sanitation and water treatment is performed unsatisfactorily and precarious, signaling the need for sustained research-driven actions on the principles of education Wake up in the population capable environmental more questioning and intervention in the local reality. This research aimed to instigate critical knowledge construction to allow greater local perception of reality, associated with insertion technique feasibility research, Community research, alternative technology of water treatment based on ultraviolet radiation-UV Tube. The Methodological development used by this social research was action research procedures where awareness, dynamic cooking workshops, adaptation and installation of UV Tube, meetings and other educational practices addressed the theme of water treatment, social issues, environment and health, among other correlated in a participative manner, reflective and harmonic among respondents and researchers. The search area was chosen as the community of rural settlement good hope, located in Z? Doca, where were installed and evaluated 05 (five) UV Tube units. Data collection took place 64 (sixty-four) interviews and questionnaires applied before the dynamics of awareness and at the end of the whole educational process in order to identify improvement in the perception of the community in relation to the subject dealt with and the local reality, and consequential changes in attitudes. The treatment of data collected in the questionnaires presented variables that were tested with the non-parametric test of Chi-square and other calculated averages of answers with their respective standard deviations and their minimum and maximum values. The results indicated favourable conditions for the adaptation and insertion of the UV tube technology showing economic viability and operational compared to similar projects successfully installed in other countries, especially the acceptance of the proposal and the ease of access to the materials needed to manufacture of UV Tube. As the analysis of educational activities related to the thematic discussion addressed significant responses were expansions and modifications in order to understand the local reality criticizes pointing, including changes to posture that assisted the search for better quality of life for the community. It is concluded that the implementation of concrete action of insertion of the UV Tube use, Dialogic and critical process of construction of knowledge based on the intrinsic relationship between action and reflection associated with the permissive criticizes of knowledge built by researched and researchers was the recipe to achieve the objectives of the survey.
A pesquisa em Educa??o Ambiental Cr?tica visa ? constru??o reflexiva e cr?tica de conhecimentos, permitindo aos indiv?duos maior contextualiza??o das rela??es socioambientais e consequentes mudan?as de atitudes voltadas para transforma??o coletiva da realidade. O munic?pio de Z? Doca, p?lo regional do Alto Turi, localizado a leste do Estado do Maranh?o, pr?ximo a divisa com o Estado do Par? ? respons?vel em articular a??es educacionais, socioambientais, pol?ticas e econ?micas para o desenvolvimento de mais 17 outros munic?pios da regi?o. Verificou-se que nestes munic?pios o saneamento ambiental e, principalmente, o tratamento de ?gua, s?o realizados de forma insuficiente e prec?ria, sinalizando a necessidade de a??es orientadas por pesquisas sustentadas nos princ?pios de uma Educa??o Ambiental capaz de despertar na popula??o maior problematiza??o e interven??o na realidade local. Esta pesquisa objetivou instigar a constru??o de conhecimentos cr?ticos aptos a permitirem maior percep??o da realidade local associada ? investiga??o da viabilidade t?cnica de inser??o, junto ? comunidade pesquisada, de tecnologia alternativa de tratamento de ?gua baseado em radia??o ultravioleta ? Tubo UV. Para o desenvolvimento metodol?gico esta pesquisa social utilizou-se de procedimentos da pesquisa-a??o em que din?micas de sensibiliza??o, oficinas de confec??o, adapta??o e instala??o do Tubo UV, reuni?es e outras pr?ticas educacionais abordaram a tem?tica do tratamento de ?gua, as quest?es sociais, ambientais e de sa?de, entre outras correlacionadas de forma participativa, reflexiva e harm?nica entre pesquisados e pesquisadores. Como ?rea de pesquisa foi escolhida a comunidade do assentamento rural Boa Esperan?a - ABE, localizada em Z? Doca onde foram instalados e avaliados 05 (cinco) unidades do Tubo UV. Para coleta de dados foram realizadas 64 (sessenta e quatro) entrevistas e aplicados question?rios antes das din?micas de sensibiliza??o e ao final de todo o processo educativo, com objetivo de identificar melhoria na percep??o da comunidade em rela??o ? tem?tica abordada e a realidade local, al?m de consequentes mudan?as de atitudes. O tratamento dos dados coletados nos question?rios apresentou vari?veis que foram analisadas com o teste n?o param?trico do Qui-Quadrado e outras, calculadas as m?dias de respostas com seus respectivos desvios padr?es e seus valores m?nimos e m?ximos. Os resultados indicaram condi??es favor?veis ? adapta??o e inser??o da tecnologia do Tubo UV apresentando viabilidade econ?mica e operacional comparada a projetos id?nticos instalados com sucesso em outros pa?ses, destacando-se a aceita??o da proposta e a facilidade de acesso aos materiais necess?rios a confec??o do Tubo UV. Quanto a an?lise das a??es educativas relacionadas a discuss?o da tem?tica abordada registraram-se significativas respostas de amplia??es e modifica??o na forma cr?tica de perceber a realidade local apontando, inclusive, mudan?as de postura que auxiliaram a busca de melhor qualidade de vida para comunidade. Conclui-se que a realiza??o da a??o concreta da inser??o do uso do Tubo UV, em processo dial?gico e cr?tico de constru??o de conhecimento pautado na rela??o intr?nseca entre a??o e reflex?o associada ? permissiva cr?tica dos saberes constru?dos por pesquisados e pesquisadores foi a receita para alcan?ar os objetivos da pesquisa.
38
Ruas, Diego Botelho. "Aplicação do processo oxidativo avançado \'H IND.2\'O IND.2\'/UV como pós-tratamento de reator anaeróbio em efluentes de indústrias de celulose kraft branqueada." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-19052008-104235/.
Full textAbstract:
A proposta desta pesquisa foi avaliar a aplicação do processo oxidativo avançado (POA), peróxido de hidrogênio (\'H IND.2\'O IND.2\') e radiação ultravioleta (UV), como pós-tratamento de um reator anaeróbio utilizado para tratar efluentes de branqueamento de indústrias de celulose kraft. O principal objetivo do pós-tratamento químico foi aumentar a biodegradabilidade e a remoção de compostos recalcitrantes nos efluentes. O tratamento biológico foi realizado por meio de reator anaeróbio horizontal de leito fixo (RAHLF), em escala de bancada, seguido pelo tratamento \'H IND.2\'O IND.2\'/UV dos efluentes. As doses do agente oxidante variaram de 50 a 500 mg \'H IND.2\'O IND.2\'/L e as aplicações de energia pela lâmpada de radiação ultravioleta foram variadas, principalmente, de 3,8 a 15,0 kWh por \'M POT.3\' de efluente tratado. Desta forma, amostras de efluentes foram coletadas de duas indústrias brasileiras de celulose kraft branqueada, originando respectivamente duas fases experimentais. Na primeira fase, o RAHLF apresentou boa estabilidade de operação, obtendo adequadas eficiências de remoção de DQO (61 ± 3%), COT (69 ± 9%), \'DBO IND.5\' (90 ± 5%) e AOX (55 ± 14%). Todavia, não ocorreu boa remoção dos compostos de absorbância na \'UV IND.254\'. Além disso, houve aumento de constituintes da lignina do afluente para o efluente do RAHLF. Por sua vez, o pós-tratamento com \'H IND.2\'O IND.2\'/UV no efluente anaeróbio proporcionou eficiência de remoção variada nos parâmetros DQO (0 a 11%), \'UV IND.254\' (16 a 35%), lignina (0 a 29%) e AOX (23 a 54%). Em relação a melhoria da biodegradabilidade, todas as dosagens de \'H IND.2\'O IND.2\' estudadas promoveram aumento na relação \'DBO IND.5\'/DQO. Para uma relação \'DBO IND.5\'/DQO média inicial igual a 0,09, correspondente ao efluente do RAHLF, o maior aumento obtido foi de 131% aplicando 500 mg \'H IND.2\'O IND.2\'/L e 7,5 kWh/\'M POT.3\'. O tratamento conjugado biológico e químico foi necessário para atingir ao padrão europeu de emissão de AOX (< 0,4 kg AOX por tonelada de polpa de celulose seca produzida). Na segunda fase, o RAHLF apresentou alguns problemas operacionais, tais como entupimento nas conexões e quebras do reator de vidro, pelo possível aumento da carga orgânica volumétrica aplicada presente nos efluentes coletados na segunda indústria de celulose. O pós-tratamento com \'H IND.2\'O IND.2\'/UV mostrou menor desempenho nessa fase experimental, o que pode ser explicado também pelo maior teor de matéria orgânica residual, lignina, alcalinidade e íons cloretos ainda remanescentes nos efluentes tratados biologicamente. Visando complementar os estudos, testes em reatores aeróbios nos efluentes do RAHLF, tratados e não tratados pelos processos \'H IND.2\'O IND.2\'/UV, foram avaliados. Os resultados demonstraram que os melhores resultados (menor tempo de aeração necessário para atingir a mesma concentração dos parâmetros avaliados) foram alcançados pelos reatores que receberam efluentes previamente tratados pelo POA. Uma avaliação simplificada do custo operacional associado com a aplicação do tratamento \'H IND.2\'O IND.2\'/UV, em escala plena, indicou um custo de R$ 1,87 por \'M POT.3\' de efluente tratado.The purpose of this research was to assess the application of the advanced oxidation processes (AOP), hydrogen peroxide (\'H IND.2\'O IND.2\') and ultraviolet radiation (UV), as post-treatment for an anaerobic reactor used to treat bleaching effluents from kraft pulp mills. The main objective of the chemical post-treatment was to increase the biodegradability and remove recalcitrant compounds from the wastewater. The biological treatment was performed in a fixed bed anaerobic horizontal reactor (FBAHR), in bench scale, followed by \'H IND.2\'O IND.2\'/UV treatment of the effluents. The oxidizer dosage varied from 50 to 500 mg \'H IND.2\'O IND.2\'/L while the energy applied by the UV lamp ranged, mainly, from 3.8 to 15.0 kWh per \'M POT.3\' of treated effluent. This way, wastewater samples were collected from two brazilian bleached kraft pulp mills thus the results were reported as two different experimental phases. In the first phase the FBAHR showed good operational stability and reached the expected removal efficiencies for COD (61 ± 3%), TOC (69 ± 9%), \'BOD IND.5\' (90 ± 5%) and AOX (55 ± 14%). However, the anaerobic treatment did not provide good removal of compounds indicated by \'UV IND.254\' absorbency. Furthermore, there was an increase of lignin from the affluent to effluent of the FBAHR. In its turn the \'H IND.2\'O IND.2\'/UV post-treatment provided a wide range of removal depending upon the dosage: COD (0 to 11%), \'UV IND.254\' (16 to 35%), lignin (0 to 29%) and AOX (23 to 54%). Regarding to the improvement in biodegradability, all dosages of \'H IND.2\'O IND.2\' applied in this work promoted an increase in the \'BOD IND.5\'/COD ratio. For an average initial \'BOD IND.5\'/COD ratio equal to 0.09, which corresponds to the FBAHR effluent, the greatest increase was 131% with 500 mg \'H IND.2\'O IND.2\'/L and 7.5 kWh/\'M POT.3\'. It was necessary to couple the anaerobic and the oxidative treatment to reach the current European allowable AOX emission load (< 0.4 kg AOX per ton of produced dried cellulose pulp). During the second phase of the experiments, the FBAHR had operational problems as plugging of the tubes and cracking of the reactor wall that may be partially attributed to the higher organic load applied, as the effluents from the second mill were stronger. The AOP post-treatment also had lower performance during this experimental phase, which may be explained by the higher concentration of the organic matter, lignin, alkalinity and chloride ions, still present in the biologically treated effluents. To complete the experiments samples from effluents of the FBAHR and AOP process were submitted to aerobic assays. By tests done in aerobic reactors in the FBAHR effluents, treated and non-treated by the processes \'H IND.2\'O IND.2\'/UV, it was verified that the best results, shorter aeration time requirement to reach the same concentration of the evaluated parameters, were obtained from reactors that received previously treated by AOP effluents. A simplified evaluation of the operational cost associated with the use of the tested AOP, in full scale, indicated a cost of R$ 1.87 per \'M POT.3\' of treated effluent.
39
Eggers, Jutta. "Remediation of groundwater from a former gas works site : treatment of a polynuclear aromatic hydrocarbon and vinyl chloride contamination by ultraviolet light, ozone and advanced oxidation processes." Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/843060/.
Full textAbstract:
The public water supply in Germany is mainly based on groundwater, and great care is taken to protect these water resources. A major challenge is, however, the remediation of polluted aquifers. Such is the case at a former gas works site in Karlsruhe, Germany. The "Gaswerk Ost" of the local gas and water supply company, the Stadtwerke Karlsruhe, was in operation for nearly 80 years until it was closed down in 1965. Unwanted by-products from the gas production still contaminate the soil and groundwater of this site. The main contaminants are benzene and polynuclear aromatic hydrocarbons (PAH) such as acenaph-thene, acenaphthylene, fluorene and fluoranthene. For remediation a novel passive methodology was planned. It was decided to install a funnel and gate system to purify the contaminated groundwater in situ by letting it pass through subterranean activated carbon reactors located downstream of the polluted site. During the construction of the remediation system a further pollutant, vinyl chloride (VC), was detected in the groundwater, a substance which could not be removed adequately by the technology employed. The objective of this research project was to find out whether the PAH and vinyl chloride could be removed from the groundwater by UV irradiation prior to the activated carbon filtration. Investigations consisted of two parts: laboratory experiments were conducted to prove the general degradability of the pollutants and field experiments were earned out to confirm these results on a pilot scale. In addition to sole UV irradiation, ozonation and advanced oxidation processes (AOPs) such as UV/aeration, UV/hydrogen peroxide and UV/ozone were performed in the laboratory to generate highly reactive hydroxyl radicals. For the contaminants present at the gas works site, the individual molar absorption coefficients were determined at 254 nm to estimate the degradation performance by direct photolysis at the main emission line of the UV lamps used for the irradiation experiments. It could be shown that all investigated substances were degradable in model test solutions prepared with reverse osmosis water, the degradation of PAH being significantly better than that of benzene and VC depending on the absorption of UV light of the individual substances. During the irradiation of acenaphthene the detection of by-products with an aromatic character showed that no complete mineralisation could, however, be achieved in an acceptable period of time. Degradation experiments performed in tap water as well as in groundwater showed slower degradation behaviour due to the high carbonate and bicarbonate concentrations and a high organic carbon content, mainly resulting from humic substances in the case of groundwater. The high iron concentration of the reduced groundwater led to an increase in turbidity during irradiation, since iron II was oxidised to iron III. In contrast to UV irradiation only, better results were achieved with combined treatment methods and with ozonation. For all methods tested in the laboratory the "Electrical Energy per Order of Magnitude" (EEO) was calculated from the degradation data, ozonation being most efficient for all investigated substances with regard to the energy consumption. On the basis of the laboratory findings it was decided to perform not only UV experiments at the gas works site but to extend the in-situ investigation programme by including ozonation. With UV irradiation the concentrations of the PAH acenaphthylene, fluorene, fluoranthene and pyrene could be reduced by nearly 90%. The total efficiency of UV irradiation in this specific groundwater was, however, unsatisfactory because the main contaminant acenaph-thene was removed by only 50% to a concentration of approximately 35 g/l (remediation target value = 0.2 g/l) although 1.33 kWh per m3 were applied with four lamp modules, each containing six lamps. In contrast to this, ozonation resulted in a complete elimination of VC and PAH as well as nearly 90% removal of benzene, thus confirming the laboratory findings. As almost all contaminants could be removed by ozonation only, combined UV/ozone treatment was not applied in situ. Ozonation technology was found to be the most favourable method for the removal of contaminants present at the former gas works site in Karlsrahe based on its practicability, economic advantages and high efficiency.
40
Dhahir, Namariq. "EFFECTS OF THERMAL AND NON-THERMAL METHODS ON THE CHEMICAL COMPOSITION AND BACTERIAL INACTIVATION OF CAMEL MILK." OpenSIUC, 2021. https://opensiuc.lib.siu.edu/dissertations/1928.
Full textAbstract:
Understanding the composition of camel milk coupled with studying the effects of thermal and non-thermal treatments on its components and bacterial inactivation were the general objectives of this dissertation. In the first study (Chapter 2), the gross composition of camel milk including milk protein, fat, casein, total solids, lactose, ash, and mineral content were analyzed. In addition, fatty acid profile, amino acid profile, protein fractions, and volatile compounds were evaluated as well. Our results revealed that camel milk has its unique nutrients profile. These findings make it easier for the researchers and consumers to understand some of the nutritional attributes of camel milk.The impact of non-thermal ultrasound treatment (900 W, 20 kHz, 100% power level) on some milk-borne microorganisms and the components of camel milk was studied in Chapter3. We reported that continuous ultrasound processing was efficient in inactivating Escherichia coli (E.coli) O157: H7 and Salmonella Typhimurium (S. Typhimurium) in camel milk without detrimental effects on milk fatty acids profile, lipid peroxides, and protein fractions except for some changes in milk volatile compounds (VC). In Chapter 4, another non-thermal technique, ultraviolet-C (UV-C) light, was applied to camel milk to study the effects of different UV-C light doses on the viability of E. coli O157:H7 and S. Typhimurium and the chemical changes to milk components. The main findings of this study were: (i) UV-C treatment at a dose of 12.45 mJ/cm2 resulted in only 3.9-log10 for both bacterial strains which did not meet the Food and Drug Administration (FDA) requirements for the 5-log pathogen reduction; (ii) the UV-C treatment at the above dose, had limited effects on camel milk components. Thermal pasteurization of milk was first introduced to prevent milk-borne infectious diseases, however, its effects on camel milk components and quality are still unknown. Therefore, in Chapter 5, we investigated the efficacy of three previously reported thermal methods: PAST-1 (65ºC/30 min), PAST-2 (72ºC/5 min), and PAST-3 (80ºC/5 min) on bacterial inactivation and some camel milk components such as the fatty acid profile, lipid peroxidation, VC, and milk protein fractions. Complete elimination (6 log10 CFU/ml reduction) of E. coli O157: H7 was achieved using all pasteurization methods, however, only 3.4 log10 CFU/ml reduction of the total viable counts was reported using PAST-1 and PAST-3 methods. We also reported that the PAST-1 and PAST-3 methods did not affect the chemical composition of camel milk. In conclusion, we assessed the main components of camel milk along with the amino fatty acid profile, acid profile, volatile compounds, and protein fractions. Thermal methods were more effective than the non-thermal methods in terms of microbial inactivation and most camel milk components were not significantly influenced by thermal and non-thermal methods.
41
Chan, Yvonne Yik Woon. "Ultraviolet treatments of sewage effluents." Thesis, London South Bank University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261143.
Full text
42
YAMAGUISHI, RENATA B. "Especiação de alumínio em águas subterrâneas na região do manancial Billings: aplicação da radiação ionizante na digestão amostral para fins analíticos e na proposta de remediação." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10568.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:42:04Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:04:42Z (GMT). No. of bitstreams: 0
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
43
Pfendler, Stéphane. "Intérêt du traitement par UV-C des communautés bactériennes, fongiques et des protistes autotrophes des biofilms colonisant la pierre patrimoniale : structure des peuplements, effets des UV-C sur la physiologie algale et innocuité du traitement vis à vis du support pictural." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD030/document.
Full textAbstract:
Dans le cadre de la conservation du patrimoine, les micro-organismes se développant sous forme de biofilm sont souvent considérés comme des agents entraînant des problèmes esthétiques et de détérioration du support colonisé. L’objectif général de cette thèse est l’utilisation de la lumière UV-C comme méthode de traitement des biofilms. Dans le but de comprendre la diversité des biofilms, les communautés bactériennes, fongiques et des protistes autotrophes ont été étudiées à l’aide d’une technique de séquençage haut débit. Puis, afin de comprendre les effets des UV-C sur les micro-algales (Chlorella sp.), des essais en laboratoire ont permis de caractériser les réponses physiologiques algales (mort cellulaire, dégradation de la chlorophylle, état de photosystème II, etc.) suite à différents traitements aux UV-C. Tous les dommages observés au niveau cellulaire et moléculaire (dont la mort cellulaire et le « bleaching » de la chlorophylle) ont permis d’optimiser la méthode de traitement. Dans le but de s’assurer de l’innocuité du traitement aux UV-C sur le support des biofilms (peintures pariétales), des pigments et des liants, utilisés à la préhistoire, ont été fortement irradiés. Les résultats ont montré que les composés inorganiques sont insensibles aux UV-C au contraire des molécules organiques. Enfin, le traitement UV-C a démontré son efficacité dans une grotte touristique en permettant d’éradiquer tous les biofilms. De plus, aucune recolonisation n’a été observée deux ans après le traitement, démontrant que la lumière UV-C est le traitement le plus écologique à ce jourDevelopment of biofilm on monument heritage are often considered as agents leading to aesthetic issues and biodeterioration of their support. The aim of this study is the use of UV-C light as alternative treatment against Lampenflora. Bacterial, algal and fungal communities were studied using new generation sequencing approach. Following UV-C treatments, physiological responses of Chlorella sp. were studied in laboratory (cell death, chlorophyll degradation, photosystem II status, etc.). Damages at cellular and molecular levels (cell death, bleaching of the chlorophyll) were taken into consideration to optimize the UV-C treatment. Then, to ensure the safety of UV-C for biofilms support (parietal paintings), several pigments and binders, used by prehistoric human, were highly irradiated. The results showed that UV-C radiations were not deleterious for inorganic compounds, while a color change was observed on organic binders. Finally, UV-C treatment has proven its effectiveness in La Glacière show cave by eradicating all biofilms. In addition, no recolonization was observed two years after treatment, showing that this treatment, which is the most environmental friendly to date, is effective over time
44
Dev, Kumar Govindaraj. "Effect of Ozone and Ultraviolet Irradiation Treatments on Listeria monocytogenes Populations in Chill Brines." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35954.
Full textAbstract:
The efficacy of ozone and ultraviolet light, used in combination, to inactivate Listeria monocytogenes in fresh (9% NaCl, 91.86% transmittance at 254 nm) and spent chill brines (20.5% NaCl, 0.01% transmittance at 254 nm) was determined. Preliminary studies were conducted to optimize parameters for the ozonation of â freshâ and â spentâ brines. These include diffuser design, comparison of kit to standard methods to measure residual ozone, studying the effect of ozone on uridine absorbance and determining presence of residual listericidal activity post ozonation.
An ozone diffuser was designed using 3/16 inch PVC tubing for the ozonation of brines. The sparger was designed to facilitate better diffusion and its efficiency was tested. The modified sparger diffused 1.44 ppm of ozone after 30 minutes of ozonation and the solution had an excess of 1 ppm in 10 minutes of ozonating fresh brine solution (200ml). Population levels of L. monocytogenes were determined at various time intervals post-ozonation (0, 10, 20, 60 min) to determine the presence of residual listericidal activity. The population post ozonation (0 minutes) was 5.31 Log CFU/ml and was 5.08 Log CFU/ml after a 60 minute interval. Therefore, residual antimicrobial effect was weak. Accuracy of the Vacu-vial Ozone analysis kit was evaluated by comparing the performance of the kit to the standard indigo colorimetric method for measuring residual ozone. The kit was inaccurate in determining residual ozone levels of spent brines and 1% peptone water. Uridine was evaluated as a UV actinometric tool for brine solutions that were ozonated before UV treatment. The absorbance of uridine (A262) decreased after ozonation from 0.1329 to 0.0512 for standard 10 minutes UV exposure duration. Absorbance of uridine was influenced by ozone indicating that the presence of ozone may hamper UV fluence determination accuracy in ozone-treated solutions.
Upon completion of diffuser design and ozone/UV analysis studies, the effect of ozone-UV combination on L. monocytogenes in fresh and spent brines was evaluated. Ozonation, when applied for 5 minutes, caused a 5.29 mean Log reduction while 5 minutes of UV exposure resulted in a 1.09 mean Log reduction of L. monocytogenes cells in fresh brines. Ten minutes of ozonation led to a 7.44 mean Log reduction and 10 minutes of UV radiation caused a 1.95 mean Log reduction of Listeria in fresh brine.
Spent brines required 60 minutes of ozonation for a 4.97 mean Log reduction in L. monocytogenes counts, while 45 minutes resulted in a 4.04 mean Log reduction. Ten minutes of UV exposure of the spent brines resulted in 0.30 mean Log reduction in Listeria cells. A combination of 60 minutes ozonation and 10 minute UV exposure resulted in an excess of 5 log reduction in cell counts. Ozonation did not cause a sufficient increase in the transmittance of the spent brine to aid UV penetration but resulted in apparent color change as indicated by change in L*a*b* values. Ozonation for sufficient time had considerable listericidal activity in fresh brines and spent brines and when combined with UV treatment, is effective reducing L. monocytogenes to undetectable levels in fresh brines.Master of Science in Life Sciences
45
Mendes, de Souza Poliana. "Study of short-wave ultraviolet treatments (UV-C) as a non-thermal preservation process for liquid egg products." Doctoral thesis, Universitat Politècnica de València, 2012. http://hdl.handle.net/10251/16696.
Full textAbstract:
La viabilidad de los tratamientos con radiación ultravioleta (UV-C) a 254 nm como proceso no térmico para la conservación de ovoproductos líquidos fue evaluada desde el punto de vista de la eficiencia en la descontaminación y sus efectos en los atributos de calidad. Los estudios cinéticos sobre la inactivación de microorganismos inoculados y de los principales grupos de microorganismos alterantes sirvieron para discriminar los parámetros más relevantes del tratamiento con UV-C. Los estudios de vida útil sirvieron para evaluar las ventajas aportadas por esta tecnología frente a tratamientos térmicos tradicionales. Las fracciones de huevo (clara, yema y huevo entero) tratadas con UV-C fueron analizadas en cuanto a los cambios de pH, color, estabilidad de lípidos (TBARS, colesterol y valor de peróxidos), efectos en las proteínas (oxidación proteica, DSC, SDS-PAGE), propiedades reológicas (viscosidad dinámica, comportamiento de flujo, viscosidad en función de la temperatura), propiedades funcionales (emulsionantes y espumantes), composición nutricional (vitaminas y minerales), composición de componentes saludables (carotenoides), y cito-genotoxicologia. Finalmente, la aceptación sensorial de los ovoproductos líquidos tratados por UV-C y de productos preparados con ovoproductos líquidos tratados por UV-C (mayonesa, bizcocho y pudin) fueron evaluadas por medio de pruebas triangulares y afectivas. El tratamiento con UV-C demostró ser una excelente alternativa a la pasteurización térmica. En microorganismos inoculados, se demostró una reducción de 5 Log tanto para Gram(+) como para Gram(-) en un equipo comercial para tratamientos en régimen continuo (UVivatec�). En tandas, los resultados también mostraron decrecimientos importantes en el recuento de microorganismos inoculados, aunque serían necesarios tiempos largos de tratamiento para producir una descontaminación comparable a la pasteurización térmica. Los ovoproductos líquidos tratados con UV-C fueron estables durante 8Mendes De Souza, P. (2012). Study of short-wave ultraviolet treatments (UV-C) as a non-thermal preservation process for liquid egg products [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16696
Palancia
46
Minaříková, Kateřina. "Metody posouzení zvýšení trvanlivosti betonových výrobků s povrchem lakovaným pomocí uzavíracího nátěru s jeho následným vytvrzením." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392364.
Full textAbstract:
This diploma thesis is focused on the description and summary of existing knowledge about vibro-pressed concrete products with treated surface with protective coating, that is hardering by ultravioled and infrared radiation. The theoretical part describes the production of vibro-presses products, possible wayt of finishing the surface including the description of the most commonly used materials and the methods of application and hardering of protrctive coating on the surface. Another point of the theoretical part is creating of lime efflorescence on the concrete surface and their subsequent disappearance. The experimental part of the thesis is ficused on obtaining information about the properties of the modified pavements by these techologies and comparing the acquired properties with the charakteristice of the reference pavements that do not have any protective coating on their surface.
47
Yaun, Brian Robert. "Efficacy of Ultraviolet Treatments for the Inhibition of Pathogens on the Surface of Fresh Fruits and Vegetables." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/9696.
Full textAbstract:
Two studies investigating the use ultraviolet light at a wavelength of 253.7nm (UVC) into the inhibition of Salmonella spp. and Escherichia coli O157:H7 were conducted. The objectives of these studies were: to determine the rates for the destruction of Salmonella and Escherichia coli O157:H7 on the surface of agar and to investigate its effectiveness on the surface of fresh produce. Multiple replications of different doses and cocktail concentrations were performed and resulted in a 5 log reduction of Escherichia coli O157:H7 at doses exceeding 8.4 mW / cm2, while a 5 log reduction for Salmonella spp. was observed at doses exceeding 14.5 mW / cm². Samples of Red Delicious apples, green leaf lettuce and tomatoes were subjected to different doses ranging from 1.5 __ 24 mW / cm2 of UVC to determine effective log reductions of microbial populations. UVC applied to apples inoculated with E. coli O157:H7 resulted in the highest log reductions of approximately 3.3 logs at 24 mW/cm2. Lower log reductions (2.19 logs) were seen on tomatoes inoculated with Salmonella spp. and leaf lettuce (2.65 and 2.79) inoculated with both Salmonella spp. and E. coli O157:H7 respectfully. Due to the low capital involved in initiating a UVC system, the use of ultraviolet energy may prove to be a beneficial mechanism to decrease pathogens on fresh produce if used in conjunction with strict adherence to a sanitation program, Good Manufacturing Practices and Good Agricultural Practices in ensuring the safety of fresh produce.Master of Science
48
Marques, Adriana. "Desinfecção de efluentes provenientes de lagoa anaeróbia com o uso de ultravioleta e peróxido de hidrogênio." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258387.
Full textAbstract:
Orientador: Bruno Coraucci FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-25T02:14:27Z (GMT). No. of bitstreams: 1 Marques_Adriana_M.pdf: 1587467 bytes, checksum: 87b1eed8c16c15a48054969fddf06d83 (MD5) Previous issue date: 2003
Resumo: Pesquisas de métodos de desinfecção alternativos à cloração vêm sendo desenvolvidas e dentre elas destacam-se a radiação ultravioleta e os processos oxidativos envolvendo geração do radical hidroxila ·OH, por meio da fotólise com uso do peróxido de hidrogênio, as quais foram investigadas neste trabalho. Utilizou-se um fotoreator linear com uma lâmpada germicida e o efluente foi bombeado com fluxo contínuo por meio de passagem única e coletado na saída para as análises físicas químicas e bacteriológicas. Os micro-organismos indicadores foram coliformes totais e fecais provenientes dos efluentes da lagoa anaeróbia. Os parâmetros monitorados nos ensaios fotoliticos e nos ensaios de mistura completa do peróxido de hidrogênio foram cor, turbidez, alcalinidade, sólidos em suspensão, pH e DQO. Os parâmetros de controle de desinfecção UV e UV/H2O2 foram a dose de radiação UV, carga bacteriana pré e pós - desinfecção, tempo de contato e volume e concentração do peróxido de hidrogênio. Os resultados demonstraram que os processos apresentaram eficiência de desinfecção bastantes significativos. No processo utilizando H2O2 com dose de 10 mg/L e tempo de contato de 45 minutos, atingui-se remoções significantes mas não totais de E.coli e coliformes fecais; enquanto que no processo fotolítico com dose de cerca de 25 mW.s/cm2 combinado com o H2O2 a remoção alcançou 99,99% para o referido parâmetro. O processo UV/H2O2 demonstrou ser o mais eficiente em comparação a UV e H2O2 permite a diminuição do volume utilizado de peróxido e do tempo de contato para uma dose de UV relativamente baixa variando de 20 a 35 mW.s/cm2 obtendo uma remoção superior a 4 ordens de magnitude
Abstract: Some alternative disinfection methods to chlorination have been developing recently, and among these, the UV irradiation and oxidation processes involving generation of OH. The use of hydrogen peroxide (H2O2), had deserved special attention, and were investigated in this work. For this purpose, it was utilized inline UV-reator with a germicide lamp. The effluent was mixed with hydrogen peroxide and was conducted through the channel of the reactor by a continue flow. The faecal micro-organisms E.coli and total coliformes were utilized as a pollution indicator combed through the entrance by a continue flow the process to be analysed. The parameters monitored in these process were colour, turbidity, alkalinity, COD and faecal coliformes. The control parameters of UV and H2O2. The results shown that both disinfection processes were efficient for anaerobic lagoon treatment. In the H2O2 process with 10 mg/L and 45 minutes. It was necessary to remove of 3 orders of magnitude faecal and total coliformes. The results shown also that the combined processes are more efficient in the microorganisms inactivation, and whereas for the low doses as 20-35 mWs/cm2 are able to remove 4 magnitude orders remove 4 orders of magnitude
Mestrado
Saneamento e Ambiente
Mestra em Engenharia Civil
49
Wright, Jim. "Utilization OF Apple Wash Treatments And Ultraviolet Light For The Elimination Of Escherichia coli O157:H7 In Apple Cider." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/42637.
Full textAbstract:
Three studies regarding Escherichia coli O157:H7 in apple cider were conducted. The objectives were: to evaluate the effectiveness of wash and sanitizers for removing E. coli O157:H7 from apples; to survey cider producer practices; and to determine the efficacy of ultraviolet light for reducing E. coli O157:H7 in cider.
Apples with a five-strain acid resistant mixture of E. coli O157:H7 were treated with 200 ppm hypochlorite, a phosphoric acid-based fruit wash, 5% acetic acid, 5% acetic acid followed by 3% hydrogen peroxide, a peroxyacetic acid-based solution, and distilled water. The water wash caused insignificant reductions. All other treatments caused significant reductions. Acetic acid and peroxyacetic acid were the most effective with reductions of 3.1 and 2.6 logs, respectively.
The survey determined that most producers are small, seasonal operations. Most use sound orchard management practices, clean and sanitize daily, sort and wash apples, use refrigeration, and try to prevent contamination. However, some use drop and damaged apples. Few use chemical sanitizers on apples, preservatives, pasteurize cider, or have HACCP programs.
Cider inoculated with the same mixture of E. coli O157:H7 was processed using a thin- film ultraviolet disinfection unit operating at 254 nm. Dosages ranged from 9,402 to 61,005 æW- sec/cm2. Treatment significantly reduced E. coli O157:H7 (pó 0.0001) with a mean reduction of 3.81 log CFU/ml. Reduction was also affected by the level of background microflora in cider. Results indicate that ultraviolet light can reduce this pathogen in cider. However, additional reduction measures are necessary to achieve the required 5 log reduction.Master of Science
50
Tosetto, Mariana de Salles. "Tratamento terciario de esgoto sanitario para fins de reuso urbano." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258688.
Full textAbstract:
Orientadores: Ricardo de Lima Isaac, Regina Maura Bueno FrancoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-05T11:45:48Z (GMT). No. of bitstreams: 1 Tosetto_MarianadeSalles_M.pdf: 2211562 bytes, checksum: 608a86bf4dcf009813ef868c3b96d5c6 (MD5) Previous issue date: 2005
Resumo: Este trabalho consistiu na análise da eficiência do tratamento terciário do efluente da Estação de Tratamento de Esgoto (ETE) Samambaia, no município de Campinas-SP, para fins de reuso em ambiente urbano. O sistema avaliado era composto das etapas de coagulação, pré-floculação em meio granular, filtração e desinfecção com radiação ultravioleta. O estudo experimental foi realizado em escala de bancada para otimização do processo de coagulação, e em escala piloto para avaliar as etapas de pré-floculação, filtração e desinfecção. Foram investigados, como coagulantes químicos, o sulfato férrico e o sulfato de alumínio, taxas de filtração de 120 e 300 m3/m2.dia, e dose de radiação UV de, aproximadamente, 95 mWs/cm2. O efluente terciário produzido na instalação piloto não foi considerado seguro sob o aspecto de saúde pública para aplicação em reuso urbano, como irrigação de parques e jardins, limpeza urbana, lavagem de veículos, combate a incêndio, entre outros, pois não atendeu as recomendações da Organização Mundial de Saúde ¿ OMS quanto à concentração de ovos de helmintos, e apresentou cistos de Giardia spp. ainda em concentrações elevadas, embora nenhuma das recomendações encontradas na literatura contemple limites para estes últimos. Os parâmetros turbidez, DBO, sólidos em suspensão, Coliformes Totais e E. coli atenderam as metas e padrões recomendados na literatura para reuso urbano
Abstract: This work consisted of efficiency analysis of tertiary treatment of effluent from a Wastewater Treatment Plant (WWTP Samambaia) that is located at the city of Campinas (São Paulo State, Brazil), for urban reuse. The system consisted of a physico-chemical treatment composed of coagulation, granular upflow flocculation, direct downflow filtration and ultraviolet disinfection. The experimental work was carried out using bench-scale tests to optimize chemical coagulation, and in a pilot installation to evaluate the flocculation, filtration and disinfection steps. Aluminum sulfate and ferric sulfate were evaluated as coagulants. Filtration rates of 120 and 300 m/day and UV doses of 95 mWs/cm2 were applied. The tertiary effluent obtained at the pilot plant was not considered safe, under the public health point of view, for urban reuse, like gardens and parks irrigation, urban cleaning, car-washing, fire protection and others, because the helminth eggs concentration, that did not comply to World Health Organization-WHO recommendation, and the high level of Giardia spp. cysts concentration detected at the tertiary-treated effluent, although the quality requirements for urban reuse do not limit this concentration. The turbidity, BOD, suspended solids and coliforms parameters were according to literature recommendation for urban reuse
Mestrado
Saneamento e Ambiente
Mestre em Engenharia Civil