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1
Whitt, Michael John-Ross. "Studies to Characterize Heavy Metal Content and Migration From Recycled PolyethyleneTerephthalate." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1350.
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Packaging Materials account for 31% of the world’s municipal solid waste. Agencies like the Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) are pushing for the increased use of recycled thermoplastic materials. Polyethylene terephthalate (PET) is a commonly recycled thermoplastic which is used to package ready-to-eat fruits and vegetables. Most recycled polyethylene terephthalate (RPET) packaging materials contain heavy metal catalysts, the most common being antimony. The recent increased use of recycled plastic materials has been suspected as the source of increased human heavy metal exposure. In this study, cadmium, chromium, nickel, lead and antimony were quantified in post-consumer RPET rigid containers and films using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Two hundred samples were tested of which 29 were found to be contaminated with heavy metals in the parts-per-million (ppm) range. Chromium was found in all the contaminated sample replicates at an average level of 8.18 ppm. Cadmium was found in all the contaminated samples as well. Lead was found in 90.4% of the contaminated samples and concentrations ranged from a low of 0.02 ppm to a high of 0.36 ppm. Nickel was found in 96.4% of the contaminated samples while antimony was found in 97.6% of the samples. Due to limited sample material, 22 of the 29 contaminated RPET rigid containers and films were tested for heavy metal migration into a 5% citric acid:water solution (w/v) or deionized water. Samples were subjected to prolonged storage at 7.2 or 22.2°C for 1, 7 or 14 days, or were exposed for 5 minutes to microwaves from a 1700-watt microwave oven set to 70% power before analysis. Leachate values were at ppb levels but were often below the ICP-AES Limits of Detection which were at also the ppb level, whether calculated for deionized water or 5% citric acid in water. No measureable levels of heavy metal were detected for any sample exposed to water, regardless of treatment. For samples exposed to 5% citrate and stored or microwaved, only chromium and nickel leached at measurable levels, and the number of RPET’s releasing measurable chromium and nickel increased with microwaving compared to the same plastics stored at 22.2 or 7.2°C. Since leaching was calculated as µg/L of heavy metal lost from the entire inner surface (1021 cm2) of a retail salad bag, actual exposure to heavy metal would be much less than measured in this study as retail fruit and vegetable packages and microwaveable pouches usually contain very little liquid in order to increase food safety. The results therefore suggest the potential for little migration of heavy metal from recycled PET to whole or fresh-cut fruits and vegetables when held at ambient or refrigerated temperatures, or when microwaved.
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Mahram, Mona, and Sadegh Shabnam Marboot. "Environmental impact and toxicity of chemicals used at University College of Borås." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19889.
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Olujimi, Olanrewaju Olusoji. "The concentrations, distribution and health risk assessment of suspected endocrine disrupting chemicals (phenols, phthalates and heavy metals) in freshwater systems of Cape Town, South Africa." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/2009.
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Thesis (DTech (Environmental Health))--Cape Peninsula University of Technology, 2012.Environmental pollution with persistent organic chemicals and inorganic trace metals is an increasingly important issue. Recently, a variety of chemicals are introduced in a very large scale on the surface water network. The main pathway of these pollutants into the environment was identified as wastewater treatment plants (WWTPs). The extended use of chemicals in many product formulations and insufficient WWTPs has lead to an increase in the levels of the detected micro-pollutants wastewater effluents. The majority of these compounds are characterized by a rather poor biodegradability. A large spectrum of pollutants present in waste as traces has been reported to exert adverse effects on human and wildlife. Even though compounds are found in wastewater in a very small amount, they may have the undesirable capability of initiating health effect on various high forms of life. This survey constitutes the first study in the City of Cape Town to report data for a variety of priority substances (phenols and phthalate esters) in WWTP effluents and receiving rivers. These results are of critical importance since the data generated are used to generate potential health risk associated with both the organic and inorganic compounds analyzed.
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Marzougui, Zied. "Élaboration de Latex magnétique fonctionnalisée pour le traitement des eaux usées par adsorption." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1311/document.
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L'objectif de cette étude était le développement de particules colloïdales magnétiques possédants un cœur magnétisable et une écorce polymère, capables d'éliminer les métaux lourds, les colorants cationiques et les perturbateurs endocriniens. Ces adsorbants pourraient être séparés magnétiquement permettant ainsi de remplacer les techniques lourdes comme la centrifugation, la sédimentation, et la filtration. Les résultats des analyses, en termes de taille, de morphologie, de composition chimique, de propriétés magnétiques et de potentiel Zeta, confirme bien l'encapsulation de cœur magnétique par une écorce en polymère, et la fonctionnalisation de la surface de ces particules. Nous avons pris comme exemple l'élimination les métaux lourds (Cu2+, Pb2+, Zn2+ et HCrO4-), le bleu de méthylène ainsi le Bisphenol A, en solutions aqueuse. La fixation de divers polluants considérés se fait via l'adsorption à la surface des particules. Divers paramètres physico-chimiques influent le phénomène d'adsorption; l'effet de la quantité d'adsorbant magnétique élaboré, l'effet pH initial du milieu, l'effet du temps de contact, ainsi l'effet de la concentration initiale des polluants sont considérés. Cette étude a montré que l'adsorption est rapide et l'équilibre est atteint au bout de 30 min. Le processus d'adsorption est fortement dépendant du pH initial du milieu. La capacité d'adsorption de Latex des particules magnétiques élaborées vis-à-vis des éléments étudiés s'avère très satisfaisante comparé aux différents adsorbants magnétiques étudiés dans la littérature. La cinétique d'adsorption pour tous les systèmes étudiés pourrait être considérée comme pseudo-deuxième ordre et le processus d'adsorption de ces éléments par les particules magnétiques suit le modèle monocouche de Langmuir. Nous nous sommes intéressé à décontaminer les effluents industriels chargés en métaux lourds, issus des bains de traitement de l'Entreprise SOPAL. Les résultats obtenus nous ont permis de déduire que les particules magnétiques sont efficaces pour la décontamination. Les latex magnétiques pourraient être recommandés comme des adsorbants rapides, efficaces, et réutilisables pour l'élimination et la récupération des métaux lourds des eaux uséesThe aim of this study was to prepare magnetic latex particles being magnetic core-polymer shell, able to remove heavy metals, cationic dyes and endocrine disrupting chemicals, by batch adsorption. These adsorbents were magnetically separated allows replacement of the heavy techniques such as centrifugation, sedimentation, and filtration by applying magnetic field.The results analysis in terms of colloidal and surface properties, transmission electron microscopy, hydrodynamic particle size, thermogravimetric analysis, and zeta-potential measurements, confirms the encapsulation of the magnetic core and the polymer shell, the surface functionalization of these particles, and the good colloidal stability. Heavy metals (Cu2+, Pb2+, Zn2+ and HCrO4-), methylene blue and Bisphenol A were taken as model of contaminants. Various physicochemical parameters influencing the adsorption phenomenon, which we have studied; the effect of adsorbents amount, the initial pH medium, the contact time, and the effect of the initial concentration of the pollutants. This study showed that the adsorption is fast and equilibrium is achieved within 30 min. The adsorption process is highly dependent on the initial pH. Adsorption capacities of the elaborated magnetic latex particles are very satisfactory when compared with different magnetic adsorbents reported in the literature. The adsorption kinetics for all the studied systems could be considered pseudo-second order model and the adsorption process of these elements by magnetic latex particles follows the Langmuir monolayer model. SOPAL wastewater sample load in heavy metals was analyzed by the prepared magnetic adsorbent. The results have enabled us to deduce that magnetic latex particles are effective for decontamination of real waste water. The prepared magnetic latex particles in this research can be recommended as fast, effective, and reusable for removal and recovery of metal ions from wastewater effluents
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Al-Asheh, Sameer. "Sorption of heavy metals by biological materials." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq26101.pdf.
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Palchetti, Ilaria. "Screen-printed sensors for heavy metal detection." Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268129.
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Bahri, Syaiful. "In situ combustion for upgrading of heavy oil." Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248917.
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Adewusi, Victor Adesegun. "Heavy oil recovery by forward in-situ combustion." Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370660.
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Rana, Bakht Bahadur. "Some physical and chemical properties of heavy metal oxide glasses." Thesis, University of Sheffield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484284.
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Hart, Abarasi. "Advanced studies of catalytic upgrading of heavy oils." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5297/.
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Heavy oil and bitumen are known to constitute high-boiling molecules which gives them characteristic high viscosity, high density/low API gravity, low yields of fuel distillates, and high heteroatom content compared to light oil. Upgrading therefore refers to the breaking down of heavy oil into oil with similar characteristics as light crude oil. The toe-to-heel air injection (THAI) and its catalytic add-on CAPRI (CAtalytic upgrading PRocess \(In-situ\)) were developed to achieve this objective down-hole. In this study, the CAPRI process was explored with the objective of controlling catalyst deactivation due to coking while increasing the extent of upgrading. The effects of reaction temperature and weight hourly space velocity on the extent of upgrading were studied in the range of 350-425\(^o\)C and 9.1-28 h\(^-\)\(^1\), respectively. In order to control premature deactivation of the catalysts due to coke and metal deposition, the following were investigated activated carbon guard-bed on top of the catalyst bed, hydrogen-addition, steam environment as a source of hydrogen-donor, and nanoparticulate catalyst. It was found that high reaction temperature of 425\(^o\)C and lower WHSV (9.1 h\(^-\)\(^1\)) improved the cracking as well as increase API gravity (~3-7\(^o\)), viscosity reduction of (81.9 %), demetallisation (9.3-12.3 %), desulphurisation (5.3-6.6 %), and higher yield of fuel distillates, respectively compared to upgrading at 350 and 400\(^o\)C. In spite of the improvement in produced oil at 425 \(^o\)C, the carbon-rejection was high (51-56.6 wt.%) compared to (42-47.8 wt.%) and (48-50.3 wt.%) when reaction was carried out at 350 and 400\(^o\)C for 25 hours operations.
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Minja, Rwaichi J. A. "Hydrocracking Boscan heavy oil with catalysts containing a zeolite component." Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5646.
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In this study, hydrodesulphurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM), and micro carbon residue (MCR) removal were investigated using residuum hydrocracking catalysts containing a zeolite component. The first family of catalysts containing H-mordenite was tested at a pressure of 13.9 MPa and at temperatures of 400 and 450$\sp\circ$C in an upward flow packed bed reactor. The results showed increased overall HDM, but decreased overall HDS, HDN, and MCR removal with increasing catalyst H-mordenite content. Analysis based on constant residence time and constant catalyst surface area, i.e., calculation of pseudo turnover frequency (PTOF) and PTOF per unit residence time, showed increased catalyst activity for all reactions with increasing catalyst H-mordenite content. The second family of catalysts containing HY was tested at the same conditions, but at temperatures of 400 and 370$\sp\circ$C. For these catalysts there was similar results compared to the first family of catalysts. Benzofuran temperature programmed desorption (TPD) measurements showed that, the number of acid sites increased with increasing zeolite (H-mordenite or HY) content in the catalysts. (Abstract shortened by UMI.)
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Whalley, Caroline. "Estimating binding strength and chemical phases of metals adsorbed to sediment components." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259990.
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Donaghy, Colin A. "Aspects of chemical marine monitoring and the impact of organotins in Strangford Lough." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358960.
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Sekaly, Amina Lula R. Carleton University Dissertation Chemistry. "Studies on chemical speciation of heavy metals in aqueous, environmental samples." Ottawa, 1995.
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Mahaweero, Thanatdej. "Extraction of Heavy Metals from Aqueous Solutions using Chitosan/Montmorillonite Hybrid Hydrogels." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1365160267.
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Zhang, Weihua. "Chemical-enhanced washing for remediation of heavy metal- and petroleum hydrocarbon-contaminated soils /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202006%20ZHANGW.
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Angle, Chandrawatee W. "Stability of heavy oil emulsions in turbulent flow and different chemical environments." Thesis, University of Manchester, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547848.
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Wireko, A. A., Катерина Олексіївна Сікора, Екатерина Алексеевна Сикора, Kateryna Oleksiivna Sikora, Микола Сергійович Линдін, Николай Сергеевич Лындин, Mykola Serhiiovych Lyndin, Наталія Іванівна Гирявенко, Наталья Ивановна Гирявенко, and Nataliia Ivanivna Hyriavenko. "Heavy metals effect on the chemical composition variations in rat uterus tissue." Thesis, The Romanian National Library, 2020. https://essuir.sumdu.edu.ua/handle/123456789/81896.
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Heavy metals (HM) belong to our vital activity's chemical components, which can be essential, potentially dangerous, and dangerous. Their acceptable concentration present in all layers of the biosphere. Simultaneously, excessive environmental pollution causes the disruption of the living organism’s microecology and imbalanced accumulation of HM in the organs. Besides, it is rather difficult to predict the pollutant effect on the body, as the organs and systems may have different sensitivity. One of these organs that can be exposed to the impact of exogenous factors is the uterus. Moreover, the unknown genesis of HM action on the uterus can lead to severe disorders of reproductive health. The aim of our study was to study the peculiarities of the chemical composition accumulation in the rat`s uterus wall under the experimental HM salts mixture influence.
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Gunawardana, Chandima Thanuja Kumari. "Influence of physical and chemical properties of solids on heavy metal adsorption." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/47312/1/Chandima_Gunawardana_Thesis.pdf.
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Partition of heavy metals between particulate and dissolve fraction of stormwater primarily depends on the adsorption characteristics of solids particles. Moreover, the bioavailability of heavy metals is also influenced by the adsorption behaviour of solids. However, due to the lack of fundamental knowledge in relation to the heavy metals adsorption processes of road deposited solids, the effectiveness of stormwater management strategies can be limited. The research study focused on the investigation of the physical and chemical parameters of solids on urban road surfaces and, more specifically, on heavy metal adsorption to solids. Due to the complex nature of heavy metal interaction with solids, a substantial database was generated through a series of field investigations and laboratory experiments. The study sites for the build-up pollutant sample collection were selected from four urbanised suburbs located in a major river catchment. Sixteen road sites were selected from these suburbs and represented typical industrial, commercial and residential land uses. Build-up pollutants were collected using a wet and dry vacuum collection technique which was specially designed to improve fine particle collection. Roadside soil samples were also collected from each suburb for comparison with the road surface solids. The collected build-up solids samples were separated into four particle size ranges and tested for a range of physical and chemical parameters. The solids build-up on road surfaces contained a high fraction (70%) of particles smaller than 150ìm, which are favourable for heavy metal adsorption. These solids particles predominantly consist of soil derived minerals which included quartz, albite, microcline, muscovite and chlorite. Additionally, a high percentage of amorphous content was also identified in road deposited solids. In comparing the mineralogical data of surrounding soil and road deposited solids, it was found that about 30% of the solids consisted of particles generated from traffic related activities on road surfaces. Significant difference in mineralogical composition was noted in different particle sizes of build-up solids. Fine solids particles (<150ìm) consisted of a clayey matrix and high amorphous content (in the region of 40%) while coarse particles (>150ìm) consisted of a sandy matrix at all study sites, with about 60% quartz content. Due to these differences in mineralogical components, particles larger than and smaller than 150ìm had significant differences in their specific surface area (SSA) and effective cation exchange capacity (ECEC). These parameters, in turn, exert a significant influence on heavy metal adsorption. Consequently, heavy metal content in >150ìm particles was lower than in the case of fine particles. The particle size range <75ìm had the highest heavy metal content, corresponding with its high clay forming minerals, high organic matter and low quartz content which increased the SSA, ECEC and the presence of Fe, Al and Mn oxides. The clay forming minerals, high organic matter and Fe, Al and Mn oxides create distinct groups of charge sites on solids surfaces and exhibit different adsorption mechanisms and bond strength, between heavy metal elements and charge sites. Therefore, the predominance of these factors in different particle sizes leads to different heavy metal adsorption characteristics. Heavy metals show preference for association with clay forming minerals in fine solids particles, whilst in coarse particles heavy metals preferentially associate with organic matter. Although heavy metal adsorption to amorphous material is very low, the heavy metals embedded in traffic related materials have a potential impact on stormwater quality.Adsorption of heavy metals is not confined to an individual type of charge site in solids, whereas specific heavy metal elements show preference for adsorption to several different types of charge sites in solids. This is attributed to the dearth of preferred binding sites and the inability to reach the preferred binding sites due to competition between different heavy metal species. This confirms that heavy metal adsorption is significantly influenced by the physical and chemical parameters of solids that lead to a heterogeneity of surface charge sites. The research study highlighted the importance of removal of solids particles from stormwater runoff before they enter into receiving waters to reduce the potential risk posed by the bioavailability of heavy metals. The bioavailability of heavy metals not only results from the easily mobile fraction bound to the solids particles, but can also occur as a result of the dissolution of other forms of bonds by chemical changes in stormwater or microbial activity. Due to the diversity in the composition of the different particle sizes of solids and the characteristics and amount of charge sites on the particle surfaces, investigations using bulk solids are not adequate to gain an understanding of the heavy metal adsorption processes of solids particles. Therefore, the investigation of different particle size ranges is recommended for enhancing stormwater quality management practices.
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Woodcock, Thomas Stuart. "Effects of Roadway-Related Physical and Chemical Habitat Alterations on Stream Ecosystems." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/WoodcockTS2002.pdf.
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Saad, Ramzi Fayez. "Selected heavy metal and organic removal from wastewater by precipitation and ozonation processes." Thesis, University of Ottawa (Canada), 1998. http://hdl.handle.net/10393/4545.
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Experiments were conducted to precipitate dissolved copper, zinc, and lead from simulated wastewater solutions as solids which could then be separated by filtration. The precipitants used were hydrated lime, as a slurry and in powdered form, aqueous ammonium hydroxide, ferrous sulphide sludge, and carbon dioxide gas. These five different chemicals, singly or in combination, were used; at least one of which was highly successful in precipitating each of the metals, removing at least 99% of that originally present. Copper and zinc were very effectively precipitated as the hydroxides with lime, whereas lead was not. Considering lead to be the most difficult metal to remove, four other chemical conditions were attempted for lead; these were ferrous sulphide alone, lime with ferrous sulphide, lime with carbon dioxide, and lime with ozone. The precipitation of lead with ferrous sulphide alone, was only partially successful with only 95% removal. The other three combinations of chemicals precipitated more than 99% of the soluble lead, giving excellent results. Furthermore, because lead is usually difficult to remove from solution, it is considered that the three new chemical combinations show strong promise for the removal of other heavy metals from wastewater solutions. Experiments were also conducted to decompose the organic compounds, formaldehyde and pyridine, in simulated wastewater solutions in a mixed reactor, using ozone and UV radiation as oxidants. Although 200 ppm Total Organic Carbon content of each of those chemicals, and a mixture of both, were completely decomposed by ozone-UV oxidation, the time taken for these decompositions ranged from about three to four hours. Such prolonged reaction times are considered too long for most wastewater treating processes. However, low concentrations of organic matter might be successfully treated using ozone/UV processes.
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Gyftopoulou, Maria E. "Synthesis and characterisation of pillared clay catalysts for hydro-cracking of heavy liquid fuels." Thesis, Aston University, 2005. http://publications.aston.ac.uk/9667/.
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A range of chromia pillared montmorillonite and tin oxide pillared laponite clay catalysts, as well as new pillared clay materials such as cerium and europium oxide pillared montmorillonites were synthesised. Methods included both conventional ion exchange techniques and microwave enhanced methods to improve performance and/or reduce preparation time. These catalytic materials were characterised in detail both before and after use in order to study the effect of the preparation parameters (starting material, preparation method, pillaring species, hydroxyl to metal ratio etc.) and the hydro cracking procedure on their properties. This led to a better understanding of the nature of their structure and catalytic operation. These catalysts were evaluated with regards to their performance in hydrocracking coal derived liquids in a conventional microbomb reactor (carried out at Imperial College). Nearly all catalysts displayed better conversions when reused. The chromia pillared montmorillonite CM3 and the tin oxide pillared laponite SL2a showed the best "conversions". The intercalation of chromium in the form of chromia (Cr203) in the interlayer clearly increased conversion. This was attributed to the redox activity of the chromia pillar. However, this increase was not proportional to the increase in chromium content or basal spacing. In the case of tin oxide pillared laponite, the catalytic activity might have been a result of better access to the acid sites due to the delaminated nature of laponite, whose activity was promoted by the presence of tin oxide. The manipulation of the structural properties of the catalysts via pillaring did not seem to have any effect on the catalysts' activity. This was probably due to the collapse of the pillars under hydrocracking conditions as indicated by the similar basal spacing of the catalysts after use. However, the type of the pillaring species had a significant effect on conversion. Whereas pillaring with chromium and tin oxides increased the conversion exhibited by the parent clays, pillaring with cerium and europium oxides appeared to have a detrimental effect. The relatively good performance of the parent clays was attributed to their acid sites, coupled with their macropores which are able to accommodate the very high molecular mass of coal derived liquids. A microwave reactor operating at moderate conditions was modified for hydro cracking coal derived liquids and tested with the conventional catalyst NiMo on alumina. It was thought that microwave irradiation could enable conversion to occur at milder conditions than those conventionally used, coupled with a more effective use of hydrogen. The latter could lead to lower operating costs making the process cost effective. However, in practice excessive coke deposition took place leading to negative total conversion. This was probably due to a very low hydrogen pressure, unable to have any hydro cracking effect even under microwave irradiation. The decomposition of bio-oil under microwave irradiation was studied, aiming to identify the extent to which the properties of bio-oil change as a function of time, temperature, mode of heating, presence of char and catalyst. This information would be helpful not only for upgrading bio-oil to transport fuels, but also for any potential fuel application. During this study the rate constants of bio-oil's decomposition were calculated assuming first order kinetics.
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Ntuli, Themba Dominic. "Preparation of chemically modified Macadamia nutshells for adsorptive removal of selected heavy metals." Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/379.
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M. Tech. (Chemistry, Faculty of Applied and Computer Science), Vaal University of TechnologyThe abundance of agricultural waste materials has led to its use as adsorbents for trace metal adsorption. The raw Macadamia nutshell (RMN) powder was treated with a hydrochloric acid solution to obtain acid modified Macadamia nutshells (AMM), and with sodium hydroxide solution to obtain base modified Macadamia nutshells (BMM). Then, the AMM and BMM materials were grafted with 0.5 M, 1 M, and 2 M acrylic acid. The different AMM grafted materials were labelled 0.5 GAM, 1 GAM and 2 GAM representing the different grafting ratios. The same naming order was followed for the BMM grafted materials, that is, 0.5 GBM, 1 GBM and 2 GBM corresponding to different concentrations used. The prepared Macadamia based adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), carbon, hydrogen, nitrogen and sulphur (CHNS) analysis, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The determination of surface properties such as the point of zero charge (pHPZC), bulk density and the surface negative charge was accomplished with appropriate wet chemistry methods. The adsorption of selected trace metals (Cu(II), Cd(II), Co(II), and Cr(VI)) was done in batch experiments. Atomic absorption spectroscopy (AAS) was used for the determination of metal ions concentrations and total Cr. The ultraviolet-visible (UV–Vis) spectroscopy was used for the determination of Cr(VI) concentration remaining in solution after adsorption. The RMN, AMM, and BMM adsorbents showed potential in removing more than 45% Cu(II) ions, but less than 30% for both Cd(II) and Co(II) ions. However, more than 90% removal of Cr(VI) ions was achieved with the same adsorbents. Consequently, only the adsorption of Cr(VI) was further investigated in the study due to the higher removal efficiency displayed by the Macadamia based biosorbents. The optimum adsorption conditions for the RMN, AMM, and BMM materials were found to be pH 2, 100 mg/L initial concentration of Cr(VI), 600 min contact time and 0.2 g adsorbent mass. The ideal conditions for the 0.5 GAM and 0.5 GBM were found to be pH 2, 25 mg/L initial concentration of Cr(VI), 180 min contact time, and 0.15 g adsorbent mass. The optimum temperature was found to be 40℃ for all materials. A volume of 20 mL was used for all batch experiments. The RMN, AMM, BMM, 0.5 GBM, and 0.5 GAM adsorption mechanisms were better described by the Langmuir isotherm which predicted a monolayer sorption process. The kinetic data fitted better to the pseudo second-order rate model which signified a chemisorption type of interaction. The thermodynamic parameters showed that the adsorption reaction was feasible, spontaneous and endothermic. The Macadamia based materials showed greater potential as adsorbents for the adsorption of Cr(VI) ions from aqueous solution compared to the other selected trace metal ions [Cd(II), Cu(II) and Co(II)].
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Jackson, Andrew William. "Analysis of soil chemical residues and other soil factors associated with past human activity." Thesis, University of Bristol, 2001. http://hdl.handle.net/1983/2f03f40f-c71c-46bd-9078-05fd07efd027.
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Zhao, Runhua. "Studies of combustion characteristics of heavy hydrocarbons in simple and complex flows." Thesis, University of Southern California, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10124457.
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The main focus of this dissertation was the experimental and numerical investigations of laminar flames of heavy liquid and solid hydrocarbons under simple (one-dimensional, steady state flow field using canonical configuration) and complex (two/three-dimensional, transient flow at high Karlovitz number) flow conditions.
A number of theories that have developed based on simplified assumptions and asymptotic analysis and more important for light fuels such as methane, were examined both experimentally and numerically in two steady state and canonical configuration, namely counter-flow configuration and Bunsen flame configuration. The counter-flow configuration was used to determine laminar flame speeds and extinction strain rates over a wide range of heavy hydrocarbons including normal alkanes (up to carbon number 16), practical gasolines and jet fuels and aromatics (cyclopentadiene). The analytical solution derived from asymptotic analysis provides good agreement for laminar flame speeds for fuel lean conditions. However notable discrepancies have been identified for fuel rich conditions due to lack of consideration of fuel-oxygen differential diffusion especially for heavy fuels for which the molecular weight disparity between oxygen and fuel is large.
For the Bunsen flame configuration, the area and angle methods were examined to measure laminar flame speeds of methane/air flames (representative of light fuel) and propane/air flames given that propane is the lightest hydrocarbon with distinctly higher molecular weight than oxygen. The results indicated that apart from issues raised from inlet boundary condition, flame extinction induced complex flow distribution at burner edge and flame tip effect, such configuration can’t produce quantitative results for fuels heavier than methane due to lack of consideration of flame speed variation to stretch for fuel/air mixtures with non-unity Lewis number.
Based on the understanding of the propagation of flames of heavy fuels, accurate measurements of laminar flame speeds were carried out using the counter-flow configuration at atmospheric pressure for a variety of complex fuel molecules for which data are non-existing and which are of direct relevance to practical fuels.
The interaction between a flame and turbulence is a fundamental aspect of combustion. To further illustrate the difference of flame behaviors between light and heavy fuels, the vortex laminar flame interaction was studied numerically in a canonical two-dimensional configuration for methane and n-dodecane flames. The n-dodecane exhibits early decomposition prior entering the flame due to the local temperature rise caused by the vortex, and such phenomenon is not observed in methane/air flames.
In summary, the main conclusion of this dissertation is that the fuel complexity that has been frequently ignored in flame research needs to be accounted for in simple and complex flows. It was shown that the fuel effects are both of physical and chemical nature.
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Elemia, Freire Constancia Felise, Simon Edin, and Chang Ho Lee. "SPME Method for Chemical Analysis of Heavy Organic Trace Compounds in Synthesis Gas." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277054.
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There currently exists no commercialized method for rapid sampling and analysis of trace tar ingas streams. Solid phase microextraction (SPME) with a polydimethylsiloxane (PDMS) solidphase has been previously investigated as a possible candidate due to its solvent-free natureand reusability. This project set out to deliver a proof of concept study to test whether SPMEcan be sufficiently tuned to analyse trace tar content in syngas below the concentration of 0.1mg/Nm 3 . Due to complications that arose from the Covid-19 pandemic, it was unfeasible tocarry out the practical elements of the project. Instead a concept design for carrying out such astudy has been successfully developed. This design envisions a two-chamber setup able tosample syngas directly from a gasifier at 60 °C and 125 °C respectively and is illustrated in thetext. It utilizes commercially available solvent tubes to cross-check and verify the SPME results.I nuläget finns det ingen kommersiell metod för att snabbt extrahera och analysera spår av tjärkomponenteri gasströmmar. Tidigare har solid phase microextraction (SPME) medpolydimetylsiloxan (PDMS) som fast fas undersökts som en möjlig kandidat då den ej kräverlösningsmedel och kan enkelt återanvändas. Detta projekt hade som mål att bevisa att SPMEkan anpassas tillräckligt känsligt för att analysera spår av tjära i syngas med en koncentration påmindre än 0,1 mg/Nm 3 . På grund av komplikationer som uppstod i samband med Covid-19pandemin var det inte möjligt att utföra den praktiska delen av projektet. Istället så har endesign tagits fram för ett koncept som beskriver hur man kan genomföra den praktiska delen.Designen beskriver en två-kammare lösning som kan användas för att ta prover från syngas somkommer direkt från en förgasare. Proverna tas vid temperaturer om 60 °C och 125 °C för attuppnå maximal känslighet. En uppsättning kommersiellt tillgängliga sorbentrör används för attkontrollera resultaten från SPME.
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Asakura, Hiroyuki. "Study of X-ray Absorption Spectroscopy of Heavy Elements and Transient Chemical Species." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/198946.
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Ho, Yuh-Shan. "Absorption of heavy metals from waste streams by peat." Thesis, University of Birmingham, 1995. http://etheses.bham.ac.uk//id/eprint/8742/.
Full textAbstract:
Adsorption of heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was investigated. The influence of pH, concentration, temperature, nature of solute, number of solutes simultaneously present, peat dose and reaction time on batch adsorption equilibria and kinetics tests were examined. Batch adsorption of copper and nickel onto peat was pH dependent, the optimum range being 4.0 to 5.0 for copper and 4.0 to 7.0 for nickel. Langmuir and Freundlich isotherms showed a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency of metal removal. The use of peat in removal of lead from aqueous solution was studied in batch experiments. Investigations included the effect of pH and temperature of adsorption. The adsorption equilibria data followed Langmuir and Freundlich models. Efficiency of lead removal depended very little on the reaction temperatures (12 to 37°C) and initial pH values (4.0 to 6.0). The results suggested that the adsorption process is endothermic for lead-peat adsorption. Kinetic data suggested involvement of a chemical rate-limiting step, and a predictive relationship was derived relating metal removal to peat dose. In comparison with other metals, nickel removal is poor, and possible reasons are discussed. Kinetic results also indicated that pore diffusion is not the only rate determining step in peat metal adsorption. A rate equation is described for the study of the kinetics of adsorption of aqueous divalent metal ions onto sphagnum moss peat for a range of conditions. An empirical model was devised for predicting percentage metal ion adsorbed. The model showed a high coefficient of correlation, indicating its reasonableness. The last section describes the results of an examination into the simultaneous adsorption by peat of several metals. Initially copper and nickel from both single- and bi-solute systems were tested. In general, pore diffusion appeared to be the rate-controlling step. The effects of competitive adsorption in batch systems for copper and nickel system was also studied in various ratios of metal concentration. A mathematical model was used successfully and shown to be predictive for various ratio of metal ions concentration in competitive adsorption. The dose effect on the uptake of metals on moss peat was also studied for bi-solute adsorption systems. The best interpretation which could be placed on the data was that the behaviour of nickel was unusual. The results also showed that the kinetics of adsorption were best described by a second-order expression rather than a first-order model. For metal ions which are of different size but are divalent metal ions, we used lead(II) and copper(II) as well as lead(II) and nickel(II) systems. The effects of competitive adsorption in batch systems indicated that copper had a greater effect on lead adsorption than did nickel. However, lead had a greater effect on nickel than copper. A copper, lead and nickel triple-solute system was also tested. The adsorption of any single metal such as copper, lead and nickel was hindered by the presence of the other metals. The competitive effect appears to have affected the three ions in the order nickel > lead > copper with nickel affected most; the adsorption capacity for each solute from the mixed solution was 15.9, 57.4 and 71.5% of that of a single-solute system for copper, lead and nickel, respectively. The kinetic results showed that the heavy metals are adsorbed fairly rapidly, and that there is a relatively good fit between experimental data and the second order model for copper, lead and nickel.
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Esalah, Jamaleddin. "Removal of heavy metals from aqueous solutions by precipitation with sodium di-(n-octyl) phosphinate." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37715.
Full textAbstract:
Two organophosphorus compounds: sodium di-(n-octyl) phosphinate and sodium di-(n-dodecyl) phosphinate, were synthesized and purified. Sodium di-(n-octyl) phosphinate was used both as a surfactant to form reverse micelles and as a precipitating agent to remove heavy metals from aqueous nitrate and chloride solutions.The heavy metals lead, cadmium, and zinc were precipitated from aqueous solutions with sodium di-(n-octyl) phosphinate (NaL) in the form of PbL 2(s), CdL2(s), and ZnL2(s). The mole ratio of NaL to lead in the feed was varied from 0.1 to 6.5, depending on the acidity of the feed. The effects of the feed pH, concentration of chloride, concentration of calcium, and of the chain length of the precipitating agent on the removal of lead, were investigated. Adding acid to the feed solution reduced the removal of lead as some of the phosphinate precipitated in the acid form as HL(s). The presence of chloride or calcium in the feed solution, up to mole ratios to lead of 250 and 2.75, respectively, had no effect on the removal of lead. The solubility of the precipitate PbL 2(s) was reduced by increasing the length of the alkyl group of the phosphinate. The removal of cadmium, zinc, and a mixture of lead, cadmium and zinc was investigated. Behavior similar to that of lead was observed. The selectivity of the precipitating agent for the three metals was in the order Zn > Pb > Cd.
The precipitating agent was completely regenerated by adding NaOH to the precipitate, and then contacted with diethyl ether to extract the reagent. The lead was completely recovered from the PbL2(s). Pure lead-free precipitating agent, and an aqueous solution of lead at a concentration 100 times its concentration in the feed, were obtained.
Using measured solubility products of the precipitates and literature values of the stability constants for the other expected reactions, the removal of metal, the loss of precipitating agent, and the equilibrium pH were predicted.
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Jernberg, Torgny. "Leaching of Lead and Other Heavy Metals from Brass Couplings under Different Hydrochemical Conditions." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-50931.
Full textAbstract:
Brass couplings are used in most piping systems for tap water. The alloy contain a variety of metal composition, amongst these metals lead is included. Lead is a toxic metal that can leach from brass when it is in contact with aqueous solutions. There are several physical and chemical conditions that affect the leaching of lead. Stagnation time, material composition and water quality are some of these conditions. The aim of this project is to generate a dataset that can be used for evaluation of the leaching of heavy metals from brass couplings during different hydrochemical conditions. By exposing brass couplings to synthetic waters various properties, analyse the results and comparing these to limits set by approval procedures it is possible to obtain a prediction on how the brass couplings might leach lead when installed in tap water systems. Results shows that at least one of the brass couplings included in this test could be unfit for usage in drinking water system installations.
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Pathirana, Chaamila Dinusha Kumari. "Influence of physico-chemical properties of biosorbents on heavy metal removal from industrial wastewater." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/200866/1/Chaamila%20Dinusha%20Kumari_Pathirana_Thesis.pdf.
Full textAbstract:
This project was a step forward in developing effective usage of agricultural waste for heavy metal removal from industrial wastewater. The study created predictive mathematical models for estimating sorption efficiency of agricultural waste, based on physico-chemical properties. This enables the quantification of the sorption performance of the sorbent used. The study outcomes provide the means for selecting sorbents with high sorption efficiency in relation to specific heavy metal species via the analysis of sorbent physico-chemical properties.
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AYO-BALI, ABIODUN Emmauel. "Geochemical Analysis of the Environmental Phases of La Barra de Santiago Estuary, El Salvador." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1556804693894507.
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Lin, Shaojie. "Wetland biomass - Chemical benefits and problems with biogas usage." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-18113.
Full textAbstract:
Constructed wetlands are largely used for water treatment both in agricultural land and for treating water from municipal and industrial waste. These wetlands need to be managed in order to work properly. How to deal with the large amount of vegetation harvested in the wetlands has withdrawn a great concern. The application of using wetland biomass as the co-substrates in anaerobic digestion was studied in this project. Plant materials, mostly Phragmites australis (common reed) from three different wetlands were used as raw material to produce biogas. The methane production using reed material harvested from municipal wastewater, industrial wastewater and an agricultural wetland are 66, 106, 144 ml/g VS respectively, which were lower than the suggested number 180ml/g VS. The gas potential remains a lot to be improved such as harvesting at summer to reduce the lignin content and changing the co-digestion mixing level to adjust to the optimal C/N ratio. Chemical analyses were performed concerning the gas yield and the residue quality. The digested residues showed a low concentration of cadmium, providing a non-toxic possibility to be spread on farm land as fertilizers, and closing the nutrient circle from land into water and back to land again. Pretreatments in the biogas process are usually focusing on the reduction of the lignocellulosic content in the raw material. Assessment of costs and benefits is needed for using wetland reed in the biogas production and applying any pretreatment methods.
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Aziz, Haji Muhammad Majdi Pehin Dato Haji Abdul. "Baseline study on chemical composition of Brunei Darussalam rivers." Thesis, Brunel University, 2005. http://bura.brunel.ac.uk/handle/2438/4820.
Full textAbstract:
The research provides data of pH and conductivity, some anions (e. g. fluoride, chloride, bromide, nitrate, phosphate and sulphate), monovalent cations (e. g sodium, ammonium and potassium), divalent cations (e. g calcium and magnesium) heavy metals (e. g. iron, copper, zinc, nickel, cobalt, cadmium and manganese) and organic compounds – from water samples of rivers of Brunei Darussalam, namely, Brunei River, Belait River, Tutong River and Temburong River. The higher values of certain parameters with respect to the acceptable standard limits for river water indicate the pollution in river water samples of the study area, make the waters unsuitable for various applications and do pose a human health hazard. The pH levels in Brunei Darussalam is quite reassuring and mostly safe. Although there are some stretches of rivers that show slightly lower levels of pH, there is no cause for any alarm as these waterways are not sources of drinking water. As for anions and cations, the only anion of significant levels detected in Brunei Rivers is chloride whereas only monovalent cation detected in significant levels, is sodium. The concentrations of chloride and sodium ions are below the standard concentrations. Brunei Rivers are still free from chloride and sodium pollution. For heavy metals, only iron is detected in Brunei Rivers. Brunei being a oil based country experiments were done to identify levels of a numbers of significant toxic organic compounds, including, toluene and benzene which have been detected in the waters of the oil mining district of Belait District but are within normal limits. The use of a photolytic cell system to achieve the photodegradation of benzene, toluene, ethylenediaminetetra-acetic acid (EDTA) and the surfactant – hexadecyltrimethyl-ammonium bromide (C19H42NBr) is reported. The system has been optimised by investigating the effects of the addition of hydrogen peroxide (H202) as an oxidant and the addition of titanium dioxide (TiO2) as a catalyst. The results show that the photolytic system can be used to achieve >99% degradation of organic contaminants. The research also includes a final chapter on management system which covers water protection, pollution control and solid waste management in Brunei. In addition to investigating various factors of the solid waste management in Brunei, the researcher has also exposed some of the weaknesses that need immediate addressing. Various measures have been suggested to make Brunei's water more efficient. Moreover, ways of preserving the high quality of Brunei's water figures in this chapter.
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Baumgärtner, Michael. "Influence of Iron Heavy-Ion Radiation on Biomarker Detectability : Determined by Raman-Spectroscopy of Cyanobacterial Carotenoids." Thesis, Umeå universitet, Kemiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-164299.
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Han, Yuwei. "Ultra-Low NOx Measurement and Emission Factors Evaluation of a Compressed Natural Gas (CNG) Heavy-Duty Engine." Thesis, University of California, Riverside, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10194518.
Full textAbstract:
Heavy duty on-road vehicles represent one of the largest sources of NO x emissions and fuel consumption in North America. Heavy duty vehicles are predominantly fueled with diesel, with the recent interest in natural gas (NG) systems. As emissions and greenhouse gas regulations continue to tighten new opportunities for advanced fleet specific heavy duty vehicles are becoming available with improved fuel economy. NOx emissions have dropped 90% for heavy duty vehicles with the recent 2010 certification limit. Additional NOx reductions of another 90% are desired for the South Coast Air basin to meet its 2023 NOx inventory requirements and the California optional low NOx standard in 2015.
One of the difficulties in quantifying NOx emissions at the levels proposed in this research (90% of the 2010 certification level ~ 0.02 g/bhp-hr) is the measurement methods are approaching their detection limit to sufficiently quantify NOx emissions. Three upgraded NO x measurement methods were considered which include a raw NOx measurement integrated with real time exhaust flow, a real-time ambient correction approach, and a trace level ambient analyzer for accurate bag analysis. In summary the improved methods varied in their success where the raw sampling approach showed to be the most accurate and precise over the rage of conditions tested.
The ISL G NZ 8.9 liter NG engine met and exceeded the target NO x emissions of 0.02 g/bhp-hr. This engine significantly reduced 97%–100% of NOx emissions compared with previous ISL G 8.9 engines. The NOx emissions decreased as the duty cycle was decreased which was the opposite trend for the diesel vehicles. It is expected NG vehicles could play a role in the reduction of the south coast NOx inventory problem given their near zero emission factors demonstrated.
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O'Brien, Anna Yosick. "Advances in the design of heavy alkaline earth metal complexes as precursors for chemical vapor deposition." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://wwwlib.umi.com/cr/syr/main.
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Ruiz-Morales, Yosadara. "The calculation and interpretation of NMR chemical shifts in compounds of transition metals and heavy elements." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ31071.pdf.
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Diz, Harry Richard. "Chemical and Biological Treatment of Acid Mine Drainage for the Removal of Heavy Metals and Acidity." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30713.
Full textAbstract:
This dissertation reports the design of a process (patent
pending) to remove iron from acid mine drainage (AMD)
without the formation of metal hydroxide sludge. The
system includes the oxidation of ferrous iron in a packed
bed bioreactor, the precipitation of iron within a
fluidized bed, the removal of manganese and heavy metals
(Cu, Ni, Zn) in a trickling filter at high (>9) pH, with
final neutralization in a carbonate bed. The technique
avoided the generation of iron oxyhydroxide sludge.
In the packed bed bioreactor, maximum substrate oxidation
rate (R,max) was 1500 mg L-1 h-1 at dilution rates of 2
h-1, with oxidation efficiency at 98%. The half-saturation
constant (similar to a Ks) was 6 mg L-1. The oxidation
rate was affected by dissolved oxygen below 2 mg L-1, with
a Monod-type Ko for DO of 0.33 mg L-1. Temperature had a
significant effect on oxidation rate, but pH (2.0 to 3.25)
and supplemental CO2 did not affect oxidation rates.
Iron hydroxide precipitation was not instantaneous when
base was added at a OH/Fe ratio of less than 3. Induction
time was found to be a function of pH, sulfate
concentration and iron concentration, with a multiple R2
of 0.84. Aqueous [Al (III)] and [Mn (II)] did not
significantly (a = 0.05) affect induction time over the
range of concentrations investigated.
When specific loading to the fluidized bed reactor exceeded
0.20 mg Fe m-2 h-1, dispersed iron particulates formed
leading to a turbid effluent. Reactor pH determined the
minimum iron concentration in the effluent, with an optimal
at pH 3.5. Total iron removals of 98% were achieved in
the fluidized bed with effluent [Fe] below 10 mg L-1.
Further iron removal occurred within the calcium carbonate
bed.
Heavy metals were removed both in the fluidized bed reactor
as well as in the trickling filter. Oxidation at pH >9
caused manganese to precipitate (96% removal); removals of
copper, nickel, and zinc were due primarily to sorption
onto oxide surfaces. Removals averaged 97% for copper,
70% for nickel and 94% for zinc.
The treatment strategy produced an effluent relatively
free of iron (< 3 mg/L), without the formation of iron
sludge and may be suitable for AMD seeps, drainage from
acidic tailings ponds, active mine effluent, and acidic
iron-rich industrial wastewater.Ph. D.
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Tennakoon, Nihal Ananda. "Effect of heavy metal contaminated sewage sludge on biological and chemical properties of coniferous forest soils." Thesis, University of Aberdeen, 1993. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU549118.
Full textAbstract:
A field study was carried out at Ardross forest, northern Scotland where heavy metal contaminated sewage sludge had been applied to a peaty podzol at rates of 500 (low) and 1000 (high) kg N ha-1 before tree (Sitka spruce) planting. Nitrogen mineralisation rates determined by field incubation of sealed cores ranged from 3.7 to 4.5 and 7.3 to 9.4 kg N h-1 over the growing season (May to September, 1991) in soils amended with low and high rates of sludge respectively. For the control soil, to which no sludge had been added, mineralisation rates ranged from 2.4 to 2.9 kg N ha-1. Mineralisation of residual sludge was estimated to be 0.56&'37 and 1.14&'37 in 1991, 8 years after sludge application at the low and high rates, respectively. Soils brought back to the laboratory and repacked according to the field profile enabled microcosm studies to be carried out to further investigate possible changes caused to N-cycling processes in coniferous forest soil due to application of heavy metal contaminated sewage sludge, and to consider possible mechanisms of any such changes. In the microcosm study, the two rates of application of sewage sludge increased N mineralisation. A linear relationship was apparent between N mineralisation and the rate of sludge application. Increased N mineralisation was associated with an increase in active fungal mycelium, biomass N and soil animal population densities. The availability of Cd, Cu, Mn, Pb and Zn was found to be related to the time of the year, with highest availability in Spring and Summer, and lowest availability in Winter. There was no evidence of any adverse effects in terms of heavy metals on the studied biological parameters and mineralisation rates in the field and microcosm studies. Total N, pH and moisture also increased due to sludge application.
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Almarshed, Abdullah. "Laboratory investigation of nanoscale dispersed catalyst for inhibition coke formation and upgrading of heavy oil during THAI process." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6470/.
Full textAbstract:
It has previously been shown that in situ upgrading of heavy oil by Toe-to-Heel Air Injection (THAI) can be augmented by surrounding the horizontal production well with an annulus of pelleted catalyst. Despite the further upgrading achieved with this configuration, the accumulation of coke and metals deposits on the catalyst and pore sites, resulting from cracking of the heavy oil, have a detrimental effect on the catalyst activity, life span and process. An alternative contacting pattern between the oil and transition metal dispersed catalysts was investigated using a stirred batch reactor, to mitigate the above mentioned challenges. The effects of different dispersed catalysts, hydrogen sources and tetralin hydrogen donor solvent were also investigated. The Taguchi method was applied to optimize the effect of reaction factors and select the optimum values that maximize level of heavy oil upgrading while suppressing coke yield. Detailed optimization of the reaction conditions for in situ catalytic upgrading of heavy oil was carried out over the following ranges of operating variables; temperature 355 – 425 \(^o\)C, reaction time 20 – 80 min, agitation 200 – 900 rpm, initial hydrogen pressure 10 – 50 bar, and iron metal loading 0.03 – 0.4 wt%.
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Peiravi, Meisam. "CONTAMINANTS REMOVAL AND RARE EARTH ELEMENTS RECOVERY FROM COAL MINE DRAINAGE BY USING (BIO)(ELECTRO) CHEMICAL METHODS." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/dissertations/1581.
Full textAbstract:
Mining activities, as essential as they are for our economy and our society, bring pollutants such as acid mine drainage (AMD) which contains dissolved metal(loid)s into the environment. There are different technologies currently being practiced to treat AMD, but many of these methods are prohibitive in industry due to high energy, material and labor requirements. This study investigated two emerging technologies to treat AMD with high removal rates of some metals. In addition, as AMD contains strategic metals such as rare earth elements (REEs), hydrometallurgical and biosorptive approaches were used to recover REEs from AMD, hydrometallurgical recovery method was also applied for coal by-products for the method developed. A two-chamber bioelectrochemical system (BES) was used to remove different types of metals from AMD. After 7 days, the pH of the cathode solution increased from 2.5 to 7.3. More than 99% of Al, Fe and Pb were removed, and removal rates of 93%, 91%, 89% and 69% were achieved for Cd, Zn, Mn, and Co, respectively, at the biocathode. Energy-dispersive X-ray spectroscopy (EDS) studies revealed the deposition of the various metals on the cathode surface, and some metals were detected in precipitates from the cathode chamber. During the BES operation, ~30-50 mV of closed circuit voltage was obtained for different conditions. A single-chambered BES study was conducted for the removal of Cd, Ni, and Mn in mine drainage. Compared to a double chamber, a single chamber BES is easier to design and operate. The removal process was studied with activated sludge from a local wastewater treatment plant. The effect of applied voltage, time, and initial concertation of these metals on their removal rate was studied. For Cd initial concentrations of 625 and 165 µg/L, 1.0 V showed the highest removal efficiency, and ~93 and 95% of Cd were removed, respectively. For a Ni initial concentration of 2,440 µg/L, 72% was removed under 1.0 V compared to the control of 77%. However, for a lower initial Ni concentration of 190 µg/L, 1.0 V was better compared than other conditions, and it removed 92% of Ni. For a Mn initial concentration of 1,800 µg/L, 1.0 V had a better result, however, only ~19% of the Mn was removed. For a lower Mn initial concentration of 390 µg/L, 1.0 V was favorable only at 24 h and the removal rate was ~37%. Nanoscale zerovalent iron (nZVI) was used to remove contaminants from AMD. These contaminants include transition metals (Co, Ni, Cu, Mn, and Zn), alkali and alkaline earth metals (Li, Mg, and Ca), metalloid (As), nonmetals (Se and S), and active metal (Al). Purchased nZVI in concentrations of 10-6500 mg/L was used for a reaction duration of up to 480 min. The pH of the AMD increased linearly with increasing concentrations of nZVI, with a maximum of 6.0±0.1 at 6500 mg/L of nZVI. Cu and Al had the highest removal rate among all other elements. With 10 mg/L of nZVI, ~100% of Cu was removed within 120 min. Up to ~98% of Al was removed with 5000 mg/L of nZVI in 480 min. Reuse of the purchased nZVI was studied for the first time for AMD treatment; however, after reuse in the second cycle, the nZVI was no longer effective. Lab-made nZVI by the precipitation method was tested for a longer time of 48 h. Removal rates for different elements did not change after ~8 h (e.g., 480 min), and in general, the lab-made nZVI had better removal efficiency compared to the purchased nZVI, with removal rate of ~28-79% when using 80 mg/L of the lab-made nZVI. Besides Cu, Al, Ni, and Co, successful removal of Mg and Ca, as well as S, Co, Li, As, and Se from AMD was reported for the first time by using nZVI. Different coal ranks were examined for REE concentration from coal ash. Maximum REE content of more than 700 mg/kg was observed for the highest-rank coal (anthracite) sample, and that was used for leaching and recovery studies. Hydrometallurgical processes including leaching, solvent extraction, stripping, and precipitation were performed to recover REEs from coal ash. Nitric acid leaching tests were conducted at 95 ℃ using a 4×2×2 factorial design. The results indicated that the highest rate of light REEs (LREEs) recovery was achieved at the highest molarity of the acid solution, lowest solids content and longest retention time. However, the highest rate of heavy REEs (HREEs) recovery needed only an intermediate level of acid molarity. The highest recovery rates of 90% for LREEs and 94% for HREEs were obtained. Recirculation of the leachate was conducted to prepare the REE-concentrated solution for the solvent extraction. After two stages of leaching, a 33 mg/L of TREE concentration was obtained in the leachate. Solvent extraction (SX) tests conducted using three different extractants, namely, TBP, D2EHPA and Cyanex 572, and their combinations showed that D2EHPA was the best extractant for recovering REEs from the nitric acid leachate solution with an extraction efficiency of 99%. Nitric acid and sulfuric acid and their mixture were used in the stripping tests. The effect of solvent concentration (in the SX process) was also studied in the stripping stage. When 50% solvent concentration was used, a maximum of 58% stripping recovery was obtained. Oxalic acid helped precipitate ~94% of total REEs (TREEs) from the above aqueous solution. Calcination of the product was performed to reach a final product of 0.8% rear earth oxides (REOs). The same process flowsheet was also successfully tested for another coal ash sample. To recover REEs from AMD, two different approaches were carried out including hydrometallurgical technique and more environmentally friendly approach- biosorptive recovery. A complete process flowsheet including either solvent extraction or biosorption, followed by stripping, and precipitation was developed to recover REEs from an unconventional source of AMD for the first time. At the natural pH of 2.5 almost all REEs were extracted from the solution. Metal-loaded organic solution was reused for three cycles, and it was shown that after three cycles, there was no major reduction in the capacity of the extractant. Striping with 6.0 M HNO3 recovered 23.9±0.7, 74.7±2.1, and 53.1±1.4% of LREEs, HREEs, and TREEs from the organic phase accordingly. Using oxalic acid, and for pH of 2.0, 92.9±2.8% of LREEs, 10±1.5% of HREEs, and 56.2±1.8% of TREEs were precipitated. In the biosorptive extraction, >99% of TREEs were extracted from the solution. The REE-bearing bacteria was also stripped with 6.0 M HNO3, 2871.3±114.8 µg/L (45.0±1.8%) LREEs, 3851.0±154.0 µg/L (65.0±2.6%) HREEs, and 6722.0±268.9 µg/L (50.0±2.0%) TREEs were obtained. Both hydrometallurgical and biosorptive methods extracted almost all of the REEs in the AMD, though pH was adjusted to 4.0 for the biosorptive method. After stripping, comparable amounts of TREEs were obtained by both methods.
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Fox, Dawn Iona. "Cactus Mucilage-Assisted Heavy Metal Separation: Design and Implementation." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3107.
Full textAbstract:
Natural contamination of groundwater by arsenic (As) has become a critical public health threat in many parts of the world. The well-known regions associated with As contamination of groundwater are Bangladesh and West Bengal, India where approximately 100 million people are exposed to high levels of arsenic by drinking arsenic-contaminated groundwater and about 35 million are already affected. Long-term drinking of arsenic-contaminated water leads to arsenicosis, which is characterized by cancers of the skin, organ disease and certain other types of cancer. Affected developing communities are at higher risk because they may not have access to conventional water treatment facilities. This problem has focused research efforts on providing accessible arsenic removal technologies. In this study, cactus mucilage, an extract from the Opuntia ficus-indica (also known as Nopal and Prickly Pear cactus), is investigated as a natural agent for As removal from water. Cactus mucilage is a natural hydrocolloid with known flocculant abilities and a demonstrated interaction with As. Two mucilage fractions were extracted - a gelling extract (GE) and a non-gelling extract (NE). Two As removal systems were studied: the cactus mucilage acting alone and a hybrid mucilage and iron treatment system. The mechanism of action of the mucilage's interaction with arsenic was also studied. Batch experiments were used to study the arsenic removal systems. Total As was determined with Hydride Generation - Atomic Fluorescence Spectroscopy (HGAFS) and Inductively Coupled Plasma - Mass Spectroscopy (ICPMS). In the hybrid system, iron (Fe) was also determined by ICP-MS. Total Organic Carbon (TOC) analysis
was used to determine mucilage concentration. Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Ultraviolet-Visible Spectroscopy (UVVIS) were used to study the molecular composition. Additionally, the mucilage was characterized by Transmission Electron Microscopy (TEM) for physical morphology and by Laser-induced Breakdown Spectroscopy (LIBS) and High Performance Liquid Chromatography (HPLC) for inorganics and sugars composition.
Both cactus extracts showed an interaction with As by binding and transporting As to the air-water interface of the treatment container, with GE and NE causing a 14% and 9% respective increase in As concentration at the air-water interface. TOC analysis showed that the mucilage migrated to the top of the treatment container but also settled on the bottom. This interaction with As was shown to be pH dependent - optimal performance was at pH 5.5 and 9. The mucilage interaction with As was also dependent on the ionic strength of the solution. ATR-FTIR showed the role of the carboxyl functional group as the binding site for the As(V). The hybrid iron-mucilage treatment system was studied in order to capitalize on the strong affinity of iron for As, as well as to exploit the flocculant properties of the mucilage. Mucilage was successfully applied as a coagulant aid in the removal of As by Fe(III) salt, achieving between 75% to 96% As removal. The process depended on the hydrolysis of the Fe(III) salt to form iron hydroxides and oxyhydroxides, which reacted with and adsorbed the dissolved As(V). The iron arsenate colloidal precipitate which formed was then adsorbed onto the mucilage surface forming larger, heavier, denser flocs. The As removal increased with increasing mucilage concentration reaching a maximum at 100 mg/L GE. Increasing Fe(III) concentration increased the As removal reaching an optimum concentration at 40 mg/L Fe. The As removal had rapid kinetics, achieving visual separation within 10 minutes and completing the majority of the removal within 30 minutes. These results are important because they demonstrate that the mucilage is the versatile basis for an As removal treatment, being able to interact as a complexant for the arsenic as well as an effective coagulant aid for iron arsenate precipitation.
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Friedrich, Karen. "Effects of a Non-Condensable Gas on the Vapex Process." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/861.
Full textAbstract:
It is estimated that Canada has 1. 7 trillion barrels of oil contained in oil sands located mainly in Alberta. However, the oil contained in the oil sands is a very viscous, tar-like substance that does not flow on its own and cannot be produced with conventional methods. Economical production of this vast resource requires new technology and research. Research in Canada has helped maintain leadership in heavy oil recovery technology. One method of viscosity reduction is through dilution, which is controlled by two mechanisms—mass transfer and gravity drainage. In the vapour extraction (Vapex) process, vapour of a light hydrocarbon solvent is injected into the reservoir. The mass transfer of vapour into bitumen is driven by a concentration gradient; the vapour diffuses into the heavy oil, causing a reduction in viscosity. The viscosity reduced oil is referred to as "live oil" and is now able to flow by gravity to a horizontal production well. At the surface, solvent can be easily separated and recovered from the produced oil through a flash separation/distillation process.
Under reservoir conditions, extraction solvents such as butane and pentane would condense, increasing the amount of solvent required and decreasing the density difference between solvent and bitumen. The solvent can be maintained in a gaseous phase, by co-injecting a non-condensable gas (NCG), reducing the partial pressure of the solvent and thus preventing condensation. Two types of models were used to observe the VAPEX process while varying the concentration of air and pentane in the system. Experimental results will help to determine the effect of increasing NCG concentration on the rate of live oil production.
The apparatus consists of a porous media model saturated with bitumen and placed inside acrylic housing. NCG (air) exists in the housing before liquid pentane is added. Pentane vapour continuously evolves from a reservoir of liquid pentane, maintained at constant temperature. A concentration gradient was established allowing pentane to flow into the system where the partial pressure of pentane in the bitumen phase is lower than the vapour pressure of pentane. The bitumen, diluted at the bitumen-gas interface, drains under the action of gravity. The advancement of the bitumen-gas interface was monitored to determine the live oil production rate. By varying the temperature of liquid pentane, the partial pressure of pentane in the extraction vessel was varied.
Results from five experiments in trough models and two in micromodels show that the rate of interface advancement in the presence of a NCG is proportional to the square root of time. Similarly, cumulative volume of oil produced was proportional to the square root of time. Previous works [Ramakrishnan (2003), James (2003), Oduntan, (2001)] have shown that interface advancement and production using a pure solvent was proportional to time. In the experimental range examined (24-32°C) temperature did not effect the rate of production for a given time or interface location.
The average steady state effective diffusion coefficient was calculated from production data to be 0. 116 cm2/s, five times larger than estimated from the Hirschfelder Equation.
Live oil properties were found to be consistent throughout each experiment and between experiments. On average, live oil contained 46-48 wt% pentane and viscosity was reduced by four orders of magnitude from 23,000 mPa?s to 4-6 mPa?s.
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Reeves, Alastair Ian. "Contaminant tracking through dendro-chemical analysis of tree-radii." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69688.
Full textAbstract:
The research used dendro-chemical analysis of ash tree rings and current year leaf litter to track Cd, Pb, Zn, Cu, Mn, Cr, and Sn spread and cycling from a closed garbage dump-toxic waste site. This technique allowed for determination of areal extent, contaminant levels and time period of initial contaminant contact. Only Zn, Sn, and Cu were found in elevated quantities in the xylem wood and Pb in the leaf litter. Elemental concentrations of Pb, Sn and Cd in xylem wood and leaves of ash were positively correlated. Tin was the only element to demonstrate a clear initial contact period and elemental accumulation with age. Significant levels of Cu accumulated in the heartwood while Zn revealed significant but inconsistent accumulated patterns. Expected attenuation zones associated with municipal solid waste landfill leachate dispersion were not found; thus the pathway for contaminant dispersion was likely through groundwater flow.An elemental index was developed to facilitate the use of dendro-chemical analysis in periods of suppressed tree growth resulting from environmental pollution.
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Ponce, de Leon Albarran Carlos. "The removal of heavy metal ions and organics from aqueous solutions using a reticulated vitreous carbon cathode cell." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240728.
Full text
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Menon, Akshay. "Partial hydrodeoxygenation of a heavy bio-based oil fraction : (A technical feasibility study)." Thesis, KTH, Kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-288988.
Full textAbstract:
This report is intended to provide the reader with an extensive background information on hydrode oxygenation (HDO) of Tall Oil Pitch (TOP), combined with results from chemical property analyses of the same. Firstly, the importance of hydrogenation and oxygen removal for a biomass-based feed material is highlighted. The chemical nature of TOP in general is described and the target for the research work is identified. It is decided to evaluate the possibility of TOP as a prospective material for achieving partial oxygen removal. The effect of catalysis on HDO behavior is assessed, and subsequently, conventional commercial catalysts are selected. Chemical analyses of the feed mixture provided data on various properties, which can then be correlated to the products from hydrogenation. Kinematic viscosity of TOP is determined, followed by acid number and saponification number tests to evaluate the free acid and total acid contents respectively. Reasoning for any deviations are highlighted and suggestions are provided to control deviation in process parameters. GC/MS analysisof the tall oil sample is also conducted to understand the presence of oxygen-containing species. Carbon residue and ash tests revealed the coking and ash forming tendency of the samples. In addition, XRF spectroscopy results indicated the metal presence in the TOP sample. Experimental trials are carried out to sulphide the catalysts prior to use in hydrogenation experiments. Catalyst sulphidation procedure is also outlined. Furthermore, the lab-scale reactor is tested for hydrogenation to determine challenges that normally arise during high-pressure working conditions. In addition to discussion of challenges regarding batch hydrogenations and sulfidations, proposals on future work in this domain is outlined, along with suggestions on an experimental pathway forward.
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Talbot, Victoria. "The chemical forms and plant availability of copper in composting organic wastes." Thesis, University of Wolverhampton, 2007. http://hdl.handle.net/2436/20493.
Full textAbstract:
A seven-step sequential extraction scheme was used to track changes in operationally defined copper speciation during the composting of a mixture of grass clippings and sawdust originating from tanalised timber. Starting materials were either unamended or treated with differing amounts of soluble copper, using a copper acetate solution, and then composted in the laboratory. Results showed that at the start of the experiment over 80% of the copper present in the unamended materials occurred in forms not immediately available for plant uptake. However, composting processes enabled the release of this copper which then, over time, became more bioavailable. Large amounts of copper in the copper amended materials were initially detectable in all fractions except the residual one, but over time it was seen to move from all fractions to the EDTA extractable fraction, thought to determine organically complexed / chelatable metals (Amir, 2005). This continued until an equilibrium was reached and then the water and calcium nitrate extractable forms appeared to hold the excess. Copper as determined by these extracts would be available for plant uptake. In the second experiment, three different organic wastes (grass/sawdust, pig slurry/sawdust and sewage sludge cake/sawdust) to which copper had been added as copper acetate, sulphate or EDTA, were composted in the laboratory. Samples were taken at 0, 105 and 318 days and subjected to a range of analyses: copper by sequential extraction using two different extraction schemes, a chelating resin membrane (CRM) procedure and by XRF spectrometry; FTIR analysis for functional groups; total carbon, nitrogen and sulphur; pH, EC, NH4+ and NO3- nitrogen, COD, germination indices and optical properties of water extracts. Sequential extractions demonstrated clear changes in copper distribution amongst various fractions within the materials, with copper originally present in the materials being transferred from the oxidisable fractions to easily extractable (and hence potentially phytoavailable) fractions. Transfer of copper from available to less available fractions in copper amended materials was also seen with movement of copper within copper EDTA treated materials being the slowest of all. Initial amounts of copper in fraction 1 extracted from all samples determined the rate at which copper was transformed. CRM determined copper correlated strongly with copper from fraction 1 of the Tessier scheme, although changes over time did not correspond well. Other parameters measured indicated that that the material was maturing (decreases in C/N and polysaccharide functional groups). However, other results demonstrated that the composts were still immature and unstable. Such slow decomposition was attributed to the high lignin content of the materials. Nevertheless, immobilisation of potentially phytotoxic level of copper was still demonstrated. The usefulness of chelating resin membrane as a predictor of phytoavailable copper is also discussed.
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Chamoun, Ninus, Viktor Kjellvertz, William Mahajan, and Yuanchao Song. "Fate of Heavy Metals in Waste to Energy (WtE) Processes." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208925.
Full textAbstract:
This study was made to increase the understanding of how heavy metals in the aqueous phase are removed at low initial concentrations in different pH and Eh values. The reaction that has been studied is mainly hydroxide precipitation and adsorption in a condensate treatment. In the study, data from one of Vattenfalls waste incinerators was analysed and the results from the data were then compared to previous studies. To increase the understanding, modelling of the heavy metals behaviour in the given concentrations was then made with Medusa and PHREEQC. The heavy metals that were analysed were Sb, As, Pb, Zn, Cr, and Cd. The low initial concentration that vary between 36.1-23600 μg/l complicates the removal process because it corresponds in a low driving force and the results are hard to compare to other studies since the initial concentrations vary between 10-100 mg/l. From the modelling and the measurement data it can be seen that Pb, Zn, Cr, and Cd was removed by hydroxide precipitation at pH 10. According to the speciation calculations, the dominant species at this pH are Pb(OH) 2 , Cd(OH)2, Zn(OH)2 and Cr(OH)3. For arsenic a clear conclusion could not be drawn from the modelling and the measurement data because of low precision. Due to the limited thermodynamic parameters of antimony in comparison with other heavy metals in the database of Medusa and PHREEQC, the modelling of antimony behaviour in condensate treatment has relatively larger uncertainty is low. The modelling results show that the main species in acidic solutions for antimony is Sb(OH)3 and in basic solutions Sb(OH)-6. Further investigation for antimony in needed for a clear conclusions to be drawn
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Peterson, Robert. "Interaction Effect of Filler Material on Fungal Biomass Activity for Heavy Metal Biosorption in Stormwater." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-14984.
Full textAbstract:
In the wake of ever more occurring and evident consequences brought by climate change such as droughts and an increasing world population, a responsible use and handling of freshwater has never been as important as before. Stormwater is more than often not treated and simply released back in nature with any kind of pollution it has collected on its way, one of which being heavy metals. By treating stormwater not only would this underutilised resource be made use of, creating a new source of freshwater, but environmental pollution caused by untreated stormwater could be potentially decreased, as it can be converted into a potential resource rather than a waste caused by nature. There are a number of already established methods to lower the concentration of heavy metals in water, however there are inherent economical and practical disadvantages with each of them. A method that has shown promising results with potential to challenge these contemporary solutions is biosorption. This study has explored the use of fungal biomass of Rhizopus oryzae for heavy metal biosorption in conjuncture with an organic filler material. The metals investigated were Zn, Cu and Fe. Moreover, the effects of pre-treating the fungal biomass with primarily NaOH were also investigated together with the optimal ratio between biomass and filler material and retention time, in order to maximise biosorption.Pre-treating the fungal biomass with NaOH resulted in a considerable increase in biosorption. Moreover, the presence of the filler material had a positive impact on biosorption by further enhancing it. The best effect was obtained at a 4:1 ratio between biomass and filler material. Finally, the best retention time was determined to be around 2 hours, slowly levelling off at higher retention times. However, the use of pre-treated R. oryzae with filler material did not prove to be efficient regarding the removal of heavy metal ions in stormwater at very low concentration of metals, between approximately 4 to 10 ppb. In the future, it would be worthwhile to investigate the viability of this method on stormwater with higher metal concentrations as well as looking into the effects of pH and temperature.Som en påföljd av de konsekvenser som klimatförändringen har orsakat, som till exempel svåra torkor tillsammans med en ökande världsbefolkning, har det blivit av allt större vikt att hanteringen av sötvatten sker på ett mer ansvarsfullt och hållbart sätt. Stormvatten brukar inte behandlas överhuvudtaget utan släpps tillbaka i miljön tillsammans med föroreningarna som det samlat på sig under sin väg, bland annat tungmetaller.Det finns redan ett antal metoder för att minska koncentrationen av tungmetaller i vatten, dock inte utan ekonomiska och praktiska svårigheter. Hur som helst så har det forskats en del kring en relativt ny metod som har tidigare visat goda resultat och skulle kunna konkurrera med befintliga lösningar, nämligen biosorption. I denna studie har man utforskat möjligheten att använda svampen Rhizopus oryzae tillsammans med ett organiskt fyllmedelsmaterial för biosorptionen av tungmetaller i stormvatten. De tungmetaller som undersöktes var Zn, Cu och Fe. Dessutom har man undersökt effekterna av ett förbehandlingssteg hos biomassan med NaOH tillsammans med det optimala förhållandet mellan biomassan och fyllemedelsmaterialet och retentionstiden för att maximera biosorptionen. Förbehandlingssteget visade en markant förbättring av biosorptionen. Fyllemedelsmaterialet hade för övrigt också en positiv inverkan genom att ytterligare öka biosorptionen. Ett 4:1 förhållande mellan biomassan och fyllemedelsmaterialet resulterade i det optimala förhållandet för komponenterna med tanke på biosorptionen. För retentionstiden visade det sig de bästa resultaten erhålles vid 2 timmar i lösningen. Emellertid visade det sig att användningen av den förbehandlade svampen tillsammans med fyllemedelsmaterialet inte var effektivt på stormvatten med en väldig låg tungmetallkoncentration, ungefär mellan 4 till 10 ppb. I framtiden skulle det vara intressant att undersöka inte bara metodens genomförbarhet på stormvatten med högre metallkoncentrationer, utan även hur pH-värde samt temperatur kan påverka resultaten.