Dissertations / Theses on the topic 'Sorption/desorption'
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Coover, James Brigham. "Phosphorus sorption and desorption in ephemeral gully erosion." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/17865.
Full textDepartment of Agronomy
Nathan O. Nelson
Phosphorus (P) is an essential nutrient in crop production, but P inputs to surface waters have resulted in impairments such as eutrophication and algae blooms. Non-point sources such as agricultural fields are a main contributor of P. Kansas, being a high agricultural dependent state, has frequent fresh water body impairments. Multiple erosion and transport processes contribute to P loss. While P loss from sheet and rill erosion has been studied extensively, P loss from ephemeral gully erosion is largely unknown. The objective of this study is to understand the effects ephemeral gullies have on the transport and transformation of P. Three fields in McPherson County with well-defined ephemeral gullies were studied. Soil samples were taken in field locations that are effected by ephemeral gullies at the 0 to 2, 2 to 5, 5 to 15, and 15 to 30 cm depths. Samples were analyzed for total P, anion exchange phosphorus (AEP) (labile P), ammonium-oxalate extractable Fe, Al, and P (Fe[subscript]ox, Al[subscript]ox, P[subscript]ox), Mehlich 3 extractable Fe, Al, Ca, and P (Fe[subscript]M3, Al[subscript]M3, Ca[subscript]M3, P[subscript]M3), equilibrium phosphorus concentration at zero net sorption (EPC[subscript]0), 1:1 soil to water pH, and texture. Soil testing showed that P quantities tend to be much higher in surface soils eroded by sheet and rill erosion and lower in subsoil soil that is eroded by ephemeral gullies. The quantity of sorptive elements such as Fe and Al, were not significantly different throughout the tested area except in areas of changing soil texture. EPC[subscript]0 testing showed it was likely that P desorbs from the surface erosion of sheet and rill and is adsorbing onto the subsoil eroded from ephemeral gullies. Sediment eroded by ephemeral gullies has a P buffering capacity greater than the sediment eroded by sheet and rill, and a small quantity of ephemeral gully subsoil will have a large effect on the dissolved P concentration of runoff. Sediment, total P loss and expected dissolved P in runoff was surveyed and modeled for two of the fields. Ephemeral gullies contributed to a majority of sediment and total P loss. The addition of ephemeral gully sediment to the erosional mix of sheet and rill sediment caused the dissolved P concentration to decrease from 0.0204 to 0.0034 mg L[superscript]-1 in one field and from 0.0136 to 0.0126 mg L[superscript]-1 in another. The results of this study show that best management practices (BMPs) such as grass waterways could cause the losses of total P to decrease as much as 2 to 12 times in fields with ephemeral gullies. However, reducing ephemeral gully erosion will likely increase dissolved P concentrations up to 600% more in runoff. Therefore, BMPs need to be combined to fully control P loss from agricultural fields.
Uygur, Veli. "Zn sorption/desorption chemistry in calcareous soils from Turkey." Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388131.
Full textWhitehead, Thomas William 1951. "Sorption and desorption of volatile alkyl halides in a desert soil." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191936.
Full textGarman, Stephanie Michelle. "Desorption Kinetics of Lead from Goethite: Effect of Mixing and Sorption Period." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/41240.
Full textMaster of Science
Mikutta, Christian. "Controls of the phosphate sorption and desorption kinetics of organic matter goethite associations." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979599083.
Full textShi, Zhenqing. "Kinetics of trace metals sorption on and desorption from soils developing predictive models /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 3.09 Mb., 309 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3205426.
Full textWang, Guohui. "Sorption, desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials." kostenfrei, 2008. http://d-nb.info/988782308/34.
Full textDavis, James Hal 1956, and James Hal 1956 Davis. "Sorption and desorption of benzene and para-xylene on an unsaturated desert soil." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/291366.
Full textKrajňáková, Soňa. "Interakce ibuprofenu s různými typy půd." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449400.
Full textPu, Xunchi. "EFFECTS OF SOIL PROPERTIES AND MICROBIAL SOURCE ON PENTACHLOROPHENOL BIOREMEDIATION." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133189415.
Full textAhart, Megan Leanne. "Sorption and desorption of the industrial chemical MCHM into polymer pipes, liners and activated carbon." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/73425.
Full textMaster of Science
Myneni, Satish Chandra Babu. "Oxyanion-mineral surface interactions in alkaline environments: AsO4 and CrO4 sorption and desorption in ettringite." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299004503.
Full textLoganathan, Vijay Anand Clement Prabhakar Feng Yucheng. "Effects of sorption and desorption on bioavailbility of atrazine in soils amended with crop residue derived char." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/LOGANATHAN_VIJAY-ANAND_27.pdf.
Full textElhaddad, Engy [Verfasser], Wolfgang [Akademischer Betreuer] Ensinger, and Christoph [Akademischer Betreuer] Schüth. "Sorption and Desorption Processes of Organic Contaminants on Carbonaceous Materials / Engy Elhaddad. Betreuer: Wolfgang Ensinger ; Christoph Schüth." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2012. http://d-nb.info/1106118332/34.
Full textSato, Shinjiro. "Phosphorus sorption and desorption in a Brazilian ultisol effects of pH and organic anions on phosphorus bioavailability /." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001359.
Full textAli, El Haj Mohammed Adam. "Sorption-desorption, extraction and mixed solvent studies of pyrethroids on soils and bed nets using GC-MS/NICI." Thesis, University of Salford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395922.
Full textLoffredo, Nicolas. "Devenir du séléniate dans les sols : mise en évidence expérimentale et modélisation des phénomènes d'hystérèse de sorption/désorption." Phd thesis, Université du Sud Toulon Var, 2011. http://tel.archives-ouvertes.fr/tel-00608532.
Full textSilva, Paulo Vinícius da. "Comportamento ambiental e bioatividade sobre plantas daninhas de herbicidas residuais aplicados sobre a palha de cana-de-açúcar em diferentes condições hídricas do solo." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-21082018-152101/.
Full textHerbicides applied to sugar cane systems, directly on the soils our by residues, are available to transport, retention and transformation phenomenon. In this context, the objective of this work was to evaluate the leaching and sorption of residual herbicides in soils with different physicochemical characteristics and in sugarcane residues. Four experiments were carried out. The first, was based on the bioassay methodology, followed the 8 x 2 x 2 factorial scheme, in a completely randomized design, with four replications, eight depths of the soil profile, two dry periods (0 and 30 days after application of the treatments (DAT) and two quantities of residues, this factorial was adopted individually for the herbicides amicarbazone (1225 g ia ha-1); imazapic (147 g i.a ha-1), sulfentrazone (800 g i.a ha-1) and tebuthiuron (900 g i.a ha-1). The herbicides were applied to the top of soil columns mounted in PVC tubes with 0 and 10 t ha-1 of straw, these treatments were submitted to the three different periods of dry (0 and 30 DATs), at the end of those times a 30 mm rainfall simulation and Cucumis sativus sowing (bioindicator plant), phytotoxicity (7, 10 and 15 DAE), dry mass and shoot height were evaluated. It was noted that the greatest phytotoxicity of the herbicide amicarbazone was in the 0-5 cm layer. And that periods of drought and straw decreased the mobility of this herbicide in the columns. In leaching tebuthiuron, imazapic and sulfentrazone the permanence of the product on the sugarcane straw during 30 DAT made the leaching of this herbicide minor. Thus, it can be concluded that the presence of straw on the soil surface coupled to the different periods of drought can affect the mobility of these herbicides in the environment. The second experiment consisted in the determination of coeficivity of adosorption and desorption (Kd and Koc) in 16 soils with different physicochemical characteristics, for the herbicides indaziflam, imazapic and amicarbazone. The C14- labeled radio-herbicide methodology was used to apply five different concentrations of the cold herbicides (0.125, 0.25, 0.50, 0.75 and 1.00 ppm), associated with the different soils and herbicides radio -marked at the concentrations of 0.24 KBq of indaziflam, 0.26 KBq of imazapic or 0.20 KBq of amicarbazone, individually in each experimental unit. The concentration of radiolabelled herbicides present in the supernatant was determined by liquid scintillation spectroscopy (LSS) and by difference between the amount initially applied and the present in the soil solution, determining adsorption. Through the same process the herbicide desorption was also evaluated in four days of analysis For imazapic and amicarbazone, Kd values were low due to their high solubility in water; however, the adsorption of imazapic was strongly influenced by the pH of the soil, and for amicarbazone the adsorption and desorption was influenced by the organic matter and pH of the soils. For indaziflam, Kd was negatively correlated with clay content but was positively correlated with organic matter. The third experiment evaluated the adsorption of indaziflam, imazapic and amicarbazone in sugarcane straw. A typical study and batch equilibrium was conducted to determine adsorption and desorption at different concentrations of the herbicides. Sugarcane residues (0.27 g) was combined with three concentrations of the herbicides (0.125, 0.5 and 1 ppm) plus 0.24 KBq of indaziflam, 0.26 KBq imazapic or 0.20 KBq of labeled amicarbazone radio. The adsorption of indaziflam, imazapic and amicarbazone was evaluated 24, 48 and 120 hours, respectively, after the contact of sugarcane residues. Indaziflam adsorption was greater than 80% at all concentrations, while imazapic adsorption was below 7% at all concentrations. The adsorption of amicarbazone was less than 20% at all concentrations. Indaziflam desorption was 30%, 28.5% and 27.5% at 0.125, 0.5 and 1 ppm, respectively, after 5 days. Maximum desorption for amicarbazone was observed at 1 ppm with 11%. The desorption for imazapic was not determined due to the low initial adsorption. A fourth experiment, addressed the interception of herbicides by sugarcane straw through simulated rainfall in various amounts of precipitation (3, 6, 12 and 24 mm). Two amounts of sugarcane straw were uniformly spread over a stainless steel screen (5 t ha-1 and 10 t ha-1), then the screen was placed on a Pyrex® pan. The rain simulations occurred at 0 hr, 24 hrs and seven days after the treatments were applied. For indaziflam, a period of seven days after application of the herbicides on the sugarcane straw was simulated a precipitation of 24 mm resulting in the removal of only 25% of the adsorbed herbicide. For the herbicide imazapic the sugarcane straw did not present an expressive barrier to interception of this product. Thus, the characteristics of the herbicides, such as water solubility and Kow, can be used to determine their dynamics in sugarcane production systems, and the leaching, straw sorption and soil attributes can a predilection for agronomic behavior and environmental fate of residual herbicides.
Ajmani, Manu. "Sorption of veterinary antibiotics to woodchips." Kansas State University, 2011. http://hdl.handle.net/2097/13169.
Full textDepartment of Civil Engineering
Alok Bhandari
In the upper Midwest, subsurface tile drainage water is a major contributor of nitrate (NO[subscript]3–N) coming from fertilizers and animal manure. Movement of NO[subscript]3-N through tile drainage into streams is a major concern as it can cause eutrophication and hypoxia conditions, as in the Gulf of Mexico. Denitrifying bioreactors is one of the pollution control strategies to treat contaminated tile drainage water. These bioreactors require four conditions which are: 1) organic carbon source, 2) anaerobic conditions, 3) denitrifying bacteria and 4) influent NO[subscript]3-N. This research focuses on investigating fate of veterinary antibiotics in woodchips commonly used in in-situ reactors. Tylosin (TYL) and sulfamethazine (SMZ) are two veterinary antibiotics which are most commonly used in the United States and can be found in tile water after manure is land applied. Partition coefficients of TYL and SMZ on wood were determined by sorption experiments using fresh woodchips and woodchips from an in situ reactor. It was concluded that the woodchips were an effective means to sorb the veterinary antibiotics leached into the tile water after application of animal manure. Linear partition coefficients were calculated and phase distribution relationships were established for both the chemicals. The fresh woodchips gave inconclusive data but predictions could be made by the information determined in the experiments using woodchips from a ten year old woodchip bioreactor. Desorption was also studied and the likelihood of desorption was predicted using the Apparent Hysteresis Index. Overall, it was found that the old woodchips allowed for quick sorption of both antibiotics. It was also found that SMZ had reversible sorption on old woodchips. Thus, it was concluded that the woodchip bioreactor would not be effective for removal of veterinary antibiotics from tile drainage. More research is required for the fate of TYL and to confirm the conclusion.
Arsego, Itacir Bandiera. "Sorção do herbicidas diuron e hexazinone em solos de texturas contrastantes." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-09092009-110016/.
Full textThe distinction of the recommendation rates of the residual herbicide found in the official recommendations for agriculture is normally based on three soil texture classes (sandy, medium and clayey), which are distinguished by the clay content in the soil top layer. However, the availability of the residual herbicides in the soil solution is function of the of the sorption process, which is determined mainly by the percent variations of the soil clay and organic matter content, and cationic exchange capacity (CEC). Therefore, the rate recommendations of residual herbicides by textural classes might not be adequate. Therefore, it was developed this research with the objective of evaluating the sorptive behavior of the herbicides diuron and hexazinone function of the four types of soil attributes of contrasting textural properties, and then verify the correlation of the soil attributes with the availability of these herbicides to plants. The soil samples were collected in four sugarcane production areas of São Paulo State, Brazil, presenting considerable variations in the content of clay (6 to 67%), sand (22 to 93%), cationic exchange capacity (CEC) (58.7 to 152.8 mmolc dm3) and organic carbon (O.C.) (13.95 to 19.19 g.kg-1). It was used the batch method with the radio labeled (14C) herbicide, using 2.0 g of soil for the herbicide diuron, and 4.0 g of soil for the herbicide hexazinone, and as herbicide extractor substance the CaCl2 in volume of 8.0 mL. Five concentrations of each herbicide were used, being for the diuron 0.19; 0.42; 0.84; 1.68 and 3.34 mg.L-1 and for hexazinone: 0.12; 0.22; 0.66; 2.17 and 6.03 mg.L-1. The sandy soil studied presented low sorption capacity and intense desorption of diuron, however, for clayey soils the sorption and retention process of diuron was more intense. The Kd values for diuron were higher in soils with higher content of O.C (g kg-1) and clay (%), so in general, the sorption of diuron was more correlated to the O.C. content of the soil, than to the clay content. The values of Kd, Koc, and Kf(sor) of the herbicide hexazinone were higher for the soils with higher content of O.C (g kg-1) and clay (%). The process of desorption of the herbicide hexazinone was intense for all the studied soils; the values of Kf(des) were higher than the respective Kf(sor), indicating that the process of desorption involves mechanisms with higher energy of linkage, than the sorption. The recommendations of herbicide rates of diuron and hexazinone to sugarcane should take into account other soil attributes, besides the texture each is normally used in the suggestions of the herbicide rates.
Minaya, Patricia [Verfasser], and Brigitte [Akademischer Betreuer] Urban. "Phosphorus Desorption and Sorption Processes in Activated Sludge Samples with Capacity to Perform EBPR Processes / Patricia Minaya. Betreuer: Brigitte Urban." Lüneburg : Universitätsbibliothek der Leuphana Universität Lüneburg, 2016. http://d-nb.info/1105035441/34.
Full textÅkerblom, Nina. "Bioavailability of pesticides in freshwater sediments : the importance of sorption and uptake routes /." Uppsala : Department of Environmental Assessment, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200703.pdf.
Full textEriksson, Johan. "Retention and mobilisation of trinitrotoluene, aniline, nitrobenzene and toluene by soil organic matter /." Umeå : Dept. of Forest Ecology, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s266.pdf.
Full textBuske, Elias. "Fuktegenskaper hos Quartzene impregnerat med salter." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-12541.
Full textInam, Deniz. "Organoclay Preparation For Anionic Contaminant Removal From Water." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606674/index.pdf.
Full text#8216
organoclay&
#8217
, can be used to remove hydrophobic organic and anionic contaminants from polluted water. Among the anionic contaminants, oxyanions such as nitrate, chromate are detrimental to human life and environment even at µ
g/L- mg/L levels. Application of organoclays for their removal from polluted water appears as one of the practical and rather cheap solution. In this study, a local clay from Ankara-Kalecik (Hanç
ili Bentonite) was modified by hexadecyltrimethylammonium bromide (HDTMA-Br) to a level of twice of its cation exchange capacity. This process alters the negatively charged surface of the clay into a positively charged one, providing sites for the removal of anionic contaminants. In this study, the degree of HDTMA+ uptake by the clay within a period of eight hours is found to be 97% of the initial amount added. In desorption studies it was revealed that only about 1% of the sorbed HTDMA+ was leached in a seven days of water-organoclay interaction revealing a rather stable organoclay structure in aqeous media. Sorption experiments with nitrate, borate, and chromate solutions were performed in order to determine the anion sorption capacity of the organoclays prepared. It turns out that while untreated clay has insignificant capacity, the modified clay can remove considerable amount of nitrate and chromate ions from aqeous solutions. While the nitrate sorption was increased about eleven fold, change in chromate sorption was reached to a level of twenty fold compared to that of the untreated clay. Sorption data for nitrate and chromate are both well described by the Langmuir isotherms. No significant change was observed in case of borate-organoclay interaction. Desorption of nitrate and chromate ions from organoclay surface were also investigated. Sorption of these oxyanions were found to be almost irreversible in aqeous media. The results imply that a properly prepared organoclay can be used for the removal of oxyanions, such as nitrate and chromate from polluted water systems.
Barizon, Robson Rólland Monticelli. "Sorção e transporte de pesticidas sob condições de não-equilíbrio." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-18112004-153828/.
Full textThe aim of this study was to evaluate the column flow and batch methods in the measurement of the imazaquin sorption: to evaluate de sorption kinetic and desorption of the imazaquin in soil by batch method and; to evaluate the time-dependent sorption of the diuron and the interaction with the aggregate size of the soil. In the first part it was evaluated the imazaquin mobility and sorption in soils with different mineralogical, physical and chemical characteristics. The imazaquin breakthrough curves were fitted by a mathematical model that considers the nonequilibrium sorption. The model provided sorption and transport parameters. In the batch method the experimental data were fitted to Freudlinch equation, which provided also the sorption parameters. In the second part were studied the imazaquin sorption/desorption in soils with with different mineralogical, physical and chemical characteristics. It was carried out by batch method and kinetics studies, which allowed quantifying the hysteresis in the sorption-desorption process. The experimental data were fitted to the Elovich equation. In the third and last part it was evaluated the time dependent sorption of the diuron and the influence of the aging and aggregate size. Samples of aged soil were extracted and combusted in pre-determined periods. It was obtained the equilibrium, sorbed and bound-residue fractions. Regarding the results, the imazaquin showed low sorption and high mobility in columns for the three soils, mainly the sandy soil. The imazaquin breakthrough curve fitted to the mathematical model that considers the nonequilibrium sorption. The miscible displacement method showed the lower values of the Kd than the batch method. This result was attributed to the nonequilibrium sorption during the imazaquin transport through the column. In the sorption/desorption study it was observed that the imazaquin sorption coefficients were low for the three soils. The RQ soil showed the lowest Kd value. This soil presented the lower clay and organic carbon content. The imazaquin desorption coefficients were higher than the sorption coefficients, evidencing that occurred hysteresis in the process. The imazaquin sorption occurred in two phases. The second phase, which is slower, seems to be influenced by diffusive processes. In the aging experiment it was noted negative correlation between extracted diuron in CaCl2 solution and organic carbon content. It was not observed interaction between the incubation period and aggregate size, demonstrating that the time dependent sorption, in this case, is not related to the soil structure. The sorbed fraction of the diuron increased during the aging, indicating that the sorption process is time dependent.
Jelena, Beljin. "Karakterizacija bioremedijacionih procesa u sedimentima zagađenim policikličnim aromatičnim ugljovodonicima i procena biodostupnosti." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2015. https://www.cris.uns.ac.rs/record.jsf?recordId=95994&source=NDLTD&language=en.
Full textThe aim of this study was to investigate: 1. The optimal conditions for the biodegradation of polycyclic aromatic hydrocarbons with the same and different numbers of rings; 2. The impact of structure and matrix biodegradation of polycyclic aromatic hydrocarbons with the same number of rings; 3. Phytotoxicity (germination tests and polycyclic aromatic hydrocarbon uptake); 4. The means for assessing the bioavailable fractions using various chemical sorbents (HPCD, βCD, MCD, XAD4 and TenaxTA) and 5. The correlation between the results of the biodegradation tests, germination tests, phytotoxicity tests and the results obtained from the experiments in the assessment of bioavailability and chemical tests. The results showed that the optimal conditions for biodegradation are achieved by the addition of mineral media, inoculum and surfactants. When considering the effect of the contents of clay and organic matter and the structure of the molecules, the highest degree of biodegradation was observed with fluoranthene, which is in line with its physico-chemical properties. The concentrations of pyrene and chrysene were not clearly correlated with the organic matter and clay contents. During thephytotoxicity tests, all seeds sprouted, which speaks in favor of a mixture of these contaminants not inhibiting the germination of the plants. Tests for the uptake of the investigated PAHs showed that the lowest percentage seed uptake was for benzo(a)pyrene, which is explained by its more complex structure. Chemical tests for evaluating bioavailability have shown that desorption in the presence of MCD, XAD4 and Tenax resins can be used as a simple method for the evaluation of a potential bioavailable fraction of organic compounds in water-sediment systems.
Vu, Cam Tu. "Comparison between granular and conventional activated sludge for trace metal elements sorption/desorption. Case of copper for landspreading application in France and in Vietnam." Thesis, Limoges, 2017. http://www.theses.fr/2017LIMO0008/document.
Full textThe spreading of sewage sludge is both ecological and economical in sofar as their quality is controlled and in particular the low level of the heavy metals available. Copper is a very common substance, naturally occurring in the environment, widely used in industry and agriculture. As a result, quantities of copper in the environment have increased, so it has been selected in this study as representing human-induced pollution to assess its mobility in relation to the quality of sludge and soil. 9 different sludges and 2 soils (grass soil from France and paddy soil from Vietnam) were studied as well as granular sludge. A methodology was developed to evaluate the effect of sludge and soil origin on copper leaching ability during sludge application for agricultural activities. Desorption tests in soil-amended sludge columns showed that: a) Whateverthe origin of soil, the centri-dried (BCD), centrifuged (BC), reed-bed (LR) sludges presented a Cu release lower than 2% while filter-pressed (BFP), digested (BD), thickened (BE) and limed (BCh) sludge amended soils increased Cu availability in soil; b) the copper leaching of granular sludge amended grass soil was higher than those measured for conventional sludge samples; c) in paddy soil, landspreading of granular sludge limited the Cu desorption compared to limed (BCh), filter-press (BFP), digested (BD) and centrifuged (BC) sludge samples. Four mechanisms groups are proposed to explain the fate of Cu in soils: 1) the control; 2) the group of Cp1, Cp2, BC, LR and BCD; 3) the group of BCh BD BE and BFP, and 4) the group of granular sludge. It is found that paddy soil containing low organic matter, application of granular sludge orother types such as composted or dried sludge can not only increase the nutrient content but also reduce the leaching capacity of copper
Neway, Bereket. "The influence of Morphology on the Transport and Mechanical Properties of Polyethylene." Doctoral thesis, KTH, Fibre and Polymer Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3668.
Full textThe sorption/desorption behaviour of n-hexane in high molarmass linear polyethylene (PE) and branched PEs with 0.39 and5.09 hexyl branches per 100 main chain C atoms andcrystallinities between 4 and 82% at 298 K has been studied.Crystal core contents determined by Raman spectroscopy werealways lower than those determined by density measurements. Then-hexane solubilities in the copolymers depended in anon-linear manner on the content of penetrable polymercomponent and were lower for homogeneous copolymers than forheterogeneous copolymers at the same contents of penetrablecomponent. The solubility of hexane in the linear PE sampleswas proportional to the volume fraction of the penetrablepolymer and the solubility was low in comparison with that ofthe branched PE of the same crystallinity. TheCohen-Turnbull-Fujita (CTF) free volume theory was capable ofdescribing the desorption process in the PEs studied. Theconcentration dependence of the thermodynamic diffusivitypredicted by the CTF free volume theory was confirmed by thedata obtained by the differential method, and the differencesbetween the results obtained by the integral and differentialmethods were within the margins of experimental error. Thedependence of the fractional free volume of the penetrablephases on the phase composition suggests that mass transporttakes place from the liquid-like component to the interfacialcomponent and that the penetrant molecules are trapped at theinterfacial sites. The linear PE samples showed a physicallyrealistic trend with a decrease in the geometrical impedancefactor (t) with decreasing degree of crystallinity, whereas theopposite trend was obtained for the copolymers. The decrease int with increasing crystallinity in the copolymers may beexplained by the presence of wide crystal lamellae in the lowcrystallinity samples.
A novel melt-extrusion method was used to createcircumferential chain orientation in pipes of crosslinked PE.The microstructure of the pipes was characterized usingdifferential scanning calorimetry (DSC), density measurements,X-ray diffraction, infrared dichroism and contractionmeasurements. The mechanical properties were assessed byuniaxial tensile tests. The maximum degree of circumferentialorientation was obtained at the inner wall of the orientedpipe. The oriented pipe material exhibited a 5-15% higherdegree of crystallinity and a greater crystal thickness thanconventionally crosslinked pipe. The circumferential and axialmoduli of the oriented, crosslinked pipe were greater than thecorresponding moduli of the non-oriented crosslinked pipe.
Blends of single-site materials of linear PE andethyl-branched PE were prepared using solution- and melt-mixingmethods. The thermal properties of the blends were studied byDSC and results obtained by the two mixing methods werecompared. Data obtained for heats of melting andcrystallization, melting and crystallization peak temperaturesand melting and crystallization temperature profiles wereessentially the same for the samples obtained by the two mixingmethods. The heat associated with the high temperature meltingpeak of the blend samples obtained by both preparation methodsafter crystallization at 398 K was higher than that of thelinear polyethylene included in the blends, suggesting that apart of the branched polyethylene crystallized at 398 K.
Key words:n-Hexane diffusion, polyethylene, free volume,solubility, sorption, desorption, mechanical properties,orientation, thermal properties, blend.
Sabah, Aboubakr. "Présence et comportement des butylétains dans les stations d'épuration des eaux usées par lagunage naturel." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS020/document.
Full textThis thesis deals with the behavior of a priority compound on the basis of the framework Directive on water at European level: tributyltin (TBT) ) and its metabolites (dibutyltin (DBT) and monobutyltin (MBT)). The study is focused on two waste stabilization pond treatment plants (WSP), which is an appropriate treatment to domestic effluents from sparsely urbanized areas.This thesis comes to fill the lack of scientific results on (1) the level of butyltin concentrations in domestic effluents from sparsely urbanized areas, in the input of the WSP and the output after treatment; (2) the efficiency of butyltins elimination by the WSP treatment; (3) the identification of the processes that control the fate of these elements during the treatment.Butyltins are measured in particulate and dissolved matrices and in sludge, by GC-ICP-MS, in all stages of the treatment by lagooning of two villages of the Department of Hérault (34, France): Gigean (6000 p.e.) and Montbazin (4500 p.e.).It is shown that the three butyltin species are consistently present in all samples taken from the two WSP. Butyltins arrive primarily in particulate form in the raw water. During treatment, the processes of sorption onto particulate matter and the settling of the latter at the bottom of each basin are the main factors for the elimination of butyltins. The first anaerobic ponds, characterized by deep depth and long residence times, allow the elimination of more than 60% Gigean (93% at Montbazin) of butyltins. Bottom sludge of each basin show high butyltins concentrations. The resuspension of butyltins is noted in the last maturation ponds, characterized by shallow depth, which may be due to re-thermal stratification. At the outlet, despite significant butyltin removal, concentrations in butyltins remain high (12 to 228 and 1.8 to 15 ng (Sn). L-1, respectively for Montbazin and Gigean).Laboratory batch experiments were conducted to study sorption processes following several experimental protocols. It was thus shown that: (1) the distribution of the butyltin species between solid and liquid phases is different from one test to another according to the operating conditions; (2) the affinity between butyltins and bottom sludge is important, regardless of its provenance. 98% of the butyltins are found in the solid phase, due to their hydrophobicity. The TBT sludge-water partition coefficient is higher than that obtained for other type of solid phases (75000 L.kg-1); (3) the process of sorption is fast.Moreover processes of sorption, desorption and dealkylation of TBT, explaining changes in concentrations of MBT and DBT in the solid phase were identified. Desorption of TBT is fast. It degrades in the liquid phase in DBT which part turns into MBT. The sorption of MBT on sludge has been systematically measured. Therefore, the sorption phenomenon is not completely reversible over time. These results help to explain the dysfunctions observed in WSP, for example after direct inputs of rainwater.This thesis shows the systematic presence of butyltin in waste stabilization pond treatment plants. In-situ data coupled with laboratory tests allow to understand the behaviour of these compounds during this treatment: the solid fraction plays a key role in the processes of sorption-desorption-(bio) degradation of butyltins
Ashworth, Hollie. "Partitioning of Sr-90 and Cs-137 in nuclear fuel storage ponds." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/partitioning-of-sr90-and-cs137-in-nuclear-fuel-storage-ponds(8ed21ee5-009d-4cd2-813a-bebad75e7a15).html.
Full textJelena, Tričković. "Primena sorpcionih parametara odabranih hidrofobnih organskih polutanata na organskoj materiji sedimenata za procenu njihove dostupnosti u sistemima sediment-voda." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2009. https://www.cris.uns.ac.rs/record.jsf?recordId=16659&source=NDLTD&language=en.
Full textNatural organic matter of soil/sediment make the main region for sorption of hydrophobic organic compounds, ant its properties influence the degree of retention and, consequently, (bio)availability of organic compounds. In order to assess the ecotoxicological risks of contaminated soils/sediments to the environment and design the appropriate remediation strategy or predict the fate and transport of organic pollutants in contaminated zones, it is necessary to understand the mechanisms of sorption/desorption at the level of the mechanism of established bonds. Study of the sorption and desorption of selected hydrophobic organic pollutants, pentachlorobenzene and lindane, on sequentially extracted humic acids and humins from a single sediment sample with the aim of finding the relationship between the structural characteristics of the isolated humic acids and humin and sorption and desorption parameters. Sorption affinity, nonlinearity of isotherms, and apparent sorption-desorption hysteresis were correlated to the sorbent characteristics obtained from elemental analysis and FTIR spectroscopic data. The proposed sorption mechanism on humic acids assumes that at low concentrations of pentachlorobenzene and lindane the sorption sites in the condensed aromatic region are occupied first, and then, at their higher concentrations, the sorption sites in the amorphous and aliphatic regions. Generally higher nonlinearity coefficient obtained for the sorption of pentachlorobenzene on umic acids compared with the nonlinearity of sorption isotherms for lindane, indicate that in the overall sorption of pentachlorobenzene of higher significance is the echanism of distribution and insertion of pentachlorobenzene molecule into hydrophobic dips of humic acids, compared to specific adsorption. These conclusions were confirmed with the results of spectroscopic investigation of intermolecular interaction of chosen organic compounds and N-methylformamide.Since suggested sorption mechanism could not explain sorption of pentachlorobenzene and lindane onto humin samples, it is supposed that the nonlinearity can be a result of surface interactions, while the high sorption affinity is result of distribution of organic compounds in the amorphous aliphatic regions that offer an excellent environment for sorption.With the aim of further insight into the sorption mechanism, investigation of desorption kinetics of three chosen hydrophobic organic compounds, pentachlorobenzene, lindane and pentachloroaniline, in the presence of soild adsorbent XAD-4 macroporous ion-exchange resin was performed. On the basis of the results obtained for sediment sample and fraction < 125 µm at two equilibrium times (15 and 90 days) and for all selected organic compounds, it can be concluded that the assessment of the potential (bio)avialable fraction of organic compounds may be obtained by using simple method of desorption in the presence of XAD-4 macroporous ion-exchange resin, performed in two ways: (1) by sediment extraction during 24 hours, when the desorbing fraction corresponds to the fraction of he compound that is found in the fast-desorbing domain of organic matter, or (2) by 6-hour extraction, when the desorbing fraction corresponds to one half of the fraction appearing in the fast-desorbing domain of the organic matter.
Berhane, Tedros Mesfin. "KINETIC AND EQUILIBRIUM SORPTION EXPERIMENTS INVESTIGATING PALYGORSKITE-MONTMORILLONITE AS A POTENTIAL FILTER MEDIUM FOR REMOVAL OF PHARMACEUTICALS AND ENDOCRINE-DISRUPTING COMPOUNDS." Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1429882830.
Full textMichel, Julien. "Transport d'hydrocarbures aromatiques polycycliques et de métaux dans les sols non saturés." Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL058N/document.
Full textPAHs and heavy metals are major soil pollutants and most of former industrial soils are co-polluted by both types of compounds. The aim of this work was to assess their transport in polluted soils under saturated and unsaturated flow conditions. This study was carried out by two approaches. First, heavy metal influence on PAH sorption and vice versa was studied with a “model” system. We showed that when the soil was simultaneously contaminated with fluoranthene and zinc, zinc retention was lower than when it was alone in the soil. As a consequence zinc would be expected to migrate more easily to the water table in co-polluted soils. Lead was more strongly retained in the presence of fluoranthene. But heavy metal influence on fluoranthene sorption was of minor importance. Then, PAH and heavy metal transport in a former coking plant soil was evaluated at the laboratory scale, under saturated and unsaturated flow conditions, by means of column experiments, and at the lysimeter scale under natural atmospheric conditions. The goal of these experiments was to compare PAH and heavy metal migration in a field-like situation with results obtained in the laboratory and to determine the appropriate experimental device for risk assessment studies. We showed that column experiments may overestimate PAH migration at the field scale. However heavy metal leaching was in accordance with what was expected from lysimeter experiments. But such experiments are rather time consuming and quite expensive, and as a consequence not adapted for risk assessment studies. Therefore we designed an original laboratory set up able to represent PAH and heavy metal migration at the field scale
Gujisaite, Valérie. "Transport réactif en milieux poreux non saturés." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL056N/document.
Full textThe aim of this work was to study the link between water flow and physical and chemical interactions in soils under variably water flow conditions, in order to improve the prediction of contaminants fate. It deals with understanding how the porous media water content can modify soil reactivity towards contaminants, and assessing the possibility to predict reactivity under unsaturated conditions with reactive solute transport studied in saturated porous media. Various processes were considered: cations exchange calcium-zinc on a model porous media (sand-kaolinite), sorption and desorption of an organic compound on a non polluted soil, transport of priority contaminants such as PAHs on an industrial contaminated soil. In each case, experiments were carried out with soil columns at the laboratory scale under saturated and unsaturated steady-state flow conditions, in order to characterize at first hydrodynamics and then to study the link with reactivity. Modeling of the breakthrough curves was then performed with codes such as CXTFIT. We showed an influence of porous media water content on reactive transport which was different as a function of the interaction. Porous media structure must also be taken into account. Ions exchange on a model porous media was not globally modified by the water content varying in a range close to saturation. On the contrary, higher sorption and lower migration of organic contaminants were observed under unsaturated conditions. Reactive transport of these compounds cannot therefore be predicted under unsaturated conditions with tests performed on saturated porous media which may overestimate transport
El, Fgaier Faycal. "Conception, production et qualification des briques en terre cuite et en terre crue." Thesis, Ecole centrale de Lille, 2013. http://www.theses.fr/2013ECLI0023/document.
Full textNowadays, the reduction of energy consumption in buildings industry represents a major issue in industrialized countries’ policies. In France, the building sector consumes about 43% of final energy and accounts for nearly a quarter of the national emissions of greenhouse gas emissions [ADEME]. It is considered as a key factor to overcome the environmental challenges we have to face.In front of these significant challenges, the thermal regulations requirements were seriously intensified during the last 40 years until the notification of the thermal regulation 2012. This latter enable the construction of low energy buildings (BBC) whose consumption is equivalent to 50 kWh/m² per year on average. This new regulation provides a strong incentive for innovation of materials, products and envelope systems. Under these conditions, improving hygrothermal performance of building materials will allow a substantial economic and environmental benefits. This work was conducted in this context. It aims to study and improve the performance of the company Briqueteries du Nord (BdN) products. It is divided in two main axis: the first consists on studying the thermal inertia and hygroscopic capacity of unfired clay bricks. However, the second axis aims to develop possible solutions for improving the thermal resistance of fired clay bricks. This research was conducted in the laboratory of the Ecole Centrale de Lille with close collaboration with the University of Artois and the BdN company
Gharemeshg, Gharavi Ayshe. "Thickness Effects In Hydrogen Sorption Of Magnesium/palladium Thin Films." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614051/index.pdf.
Full textwhile a considerable portion of the thicker films remain unreacted. Significance of this is discussed with reference to the design of hydrogen storage systems based on thin films or nanoparticles.
Flower, Hilary. "Phosphorus Sorption Dynamics in Shallow Groundwater, Coastal Everglades, Florida, USA." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5946.
Full textNiemeyer, Antje. "Prozessanalyse mit Hilfe von mathematischen und statistischen Methoden am Beispiel von Ad- und Desorption im Boden /." Aachen : Shaker, 2000. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009102162&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full textBrouard, Yoann. "Caractérisation et optimisation d'un composite biosource pour l'habitat." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR4024.
Full textThe purpose of this study was to compare hygrothermal acoustical and mechanical properties ot different materials based on vegetal aggregates and clay in order to characterize the performances of different biocomposites to provide building insulation solutions with a view to valorizing agricultural waste. We first analyzed the raw materials in order to get the density, thermal and hydric properties of the vegetal aggregates in one hand and the mineralogy and gravimetric data of the selected crude earth in the other hand. Thermal behavior of earth:vegetal aggregates mixes have been investigated at different humidity rates and different density ranges. Additionally, hydric properties have been measured to produce sorption and desorption curves and moisture buffer values (MBV) in one hand and capillarity of both aggregates and biocomposites on the other hand. One of the main interests of this study is to confirm that a wide range of locally produced vegetal byproducts could be used as - bioaggregates for concretes. Local biomaterials industries could therefore emerge depending on the locally available resources at country scale
Cong, Lili. "Sorption/desorption of arsenic to nanometer scale magnetite." Thesis, 2005. http://hdl.handle.net/1911/18750.
Full textChou, Yi-Shin, and 周怡馨. "Sorption and Desorption Study of Biofuels in Aquifer." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/95801028942665592252.
Full text高雄師範大學
生物科技系
98
The high fuel price triggered awareness among many countries of their vulnerability to oil shortages. The dwindling fossil fuel sources and the creasing dependency on imported crude oil have led to a major interest in expanding the use of bioenergy in many countries. Therefore, Taiwan is promoting the use of E3 (gasoline with addition of 3% ethanol) and B1 (diesel fuel with addition of 1% biodiesel) in 2007 and 2008, respectively. Consequently, a thorough understanding of the environment fate of potential biofuels additives (i.e., ethanol, biodiesel) and the influence that these compounds may have on the fate of other fuel constituents should be obtained before biofuels widely utilized. In this study, batch and column experiments were designed to simulate potential spills of biofuels in the subsurface environment and to evaluate the sorption behavior of hydrophobic organic compounds (HOCs) of biofuels in soils. This study provides fast estimation of contamination potential of target compounds (i.e., monoaromatic and polyaromatic hydrocarbons), and possibly other organic contaminants in various types of soil. The extent and reversibility of sorption of major components from biofuels onto major soils and groundwater was determined. The results showed that when the proportion of ethanol in gasoline increased, the easier desorption of pollutants to water occurred, which is obvious when ethanol content exceeds 25%. However, if more biodiesel was added to diesel fuel, sorption of HOCs increased. In addition, when content of soil organic carbon was increased, desorption of target compounds was decreased. The empirical relationship between Koc and water solubility (S), Koc and octanol-water partition coefficient (Kow) were established as the follings: logKoc = 0.6212 logKow+0.7919 logKoc = 0.4172 logS + 3.5475 This study will provide a basis to predict fate and transport of HOCs due to spills of biofuels. The spill scenarios generated may assist the assessment of biofuel contaminated sites.
Chang, Kwo-Ping, and 張國平. "Sorption and Desorption Behavior of Cesium in Soil." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/11483102122269020002.
Full textHsiao, Chien-hung, and 蕭健宏. "Carbon dioxide sorption/ desorption characteristics of coals in Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/89508266068570651926.
Full text國立中央大學
應用地質研究所
101
Geological sequestration of CO2 into depleted oil reservoir, saline aquifer or unmineable coal seam is now being actively investigated for the purpose of reducing greenhouse gas in the atmosphere. Understanding the physical, chemical, and thermodynamic phenomena occurred with CO2 injection is very important in making a reliable prediction of sequestration. This study examined the feasibility of carbon dioxide sequestration into unmineable coal seams in Taiwan. A total of 20 Miocene-aged coal samples from Western Foothill Belt, NW Taiwan, were collected. The stratigraphy include Mushan, Shihti, and Nanchuang Formation from bottom up. Proximate and petrographic analyses include maceral composition and vitrinite reflectance were also measured. Carbon dioxide adsorption isotherms were analyzed at 35℃ and up to 800 psi, by using a gravimetric ad/desorption apparatus. Isotherms were then fitted with a modified Langmuir Isotherm model by using Langmuir Pressure and Langmuir Volume so the model can be applied to supercritical conditions. According to the result of adsorption experiment, the pressure and temperature were quite significant. The gas storage capacity of CO2 was about 250~500 scf/ton at pressure up to 800 psi. Comparing the results of adsorption capacity with Proximate and Petrographic analyses, the Langmuir Volume shows a strong positive correlation with fixed carbon and vitrinite content. Furthermore, Adsorption capacity is closely related to micropores which were also rank and maceral dependent. It is noticed that the observed coal pore structures were affected by rank, and thus exhibit different diffusion rate. Finally, images under SEM were evaluated to understand the pathways of gas sorption.The filling mineral matter (mostly clay) will lead to the decrease of gas sorption.
Li, Chia-feng, and 李佳峰. "Dynamics of bacteriophages’ sorption and desorption in sandy soil." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/vv5vtj.
Full text逢甲大學
環境工程與科學所
91
During the outbreak of foot-and-mouth disease in pigs in 1997, the corpses of ill pigs were buried. To study whether the residual viruses on corpses have penetrated and polluted the ground water, a simulation model can be used to study the transport of bacteriophage in soil. The main object of this study was to establish a model that exhibited transport of bacteriophage in soil, especially the effect of inactivation and desorption on bacteriophage transportation were taken into consideration. Several parameters were obtained from batch experiments, and based on the equations used in the adsorption of phages to soil, the parameters of adsorption, desorption and inactivation were the key factors affected the reaction between bacteriophage and Ottawa sand. The results from batch experiments showed that the adsorption equilibrium time of bacteriophages and Ottawa sands was 60 minutes. To ensure the consistency of unit measurement, the concentration of free bacteriophage ( ) and the concentration of bacteriophages adsorbed to sand ( ) were multiplied with, and , solid-liquid conversion coefficients. The results from batch experiments were used along with Taylor’s expansion to obtain the adsorption coefficient, =2.23 10-11 and the amount of saturated adsorptive bacteriophage on Ottawa sand, = 4.3 107 PFU/g. In addition, two functions were obtained from batch experiment, that was the and varied with the concentration of bacteriophage (C), and . Finally, simulation was performed on the bacteriophage transport model. The soil condition, such as velocity ( ) and diffusion coefficient ( ) were especially examined. The pressure of Ottawa sand in soil column (pressure factor ) was then taken into consideration to modify the model and verify the relationship between the effluent of bacteriophage from the soil column as well as the validity of simulation model.
Yuan, Guoshu. "Sorption/desorption of organic compounds by soil organic matter /." 1999. https://scholarworks.umass.edu/theses/3478.
Full textMuller, Heike K. "Laboratory study of chromium sorption and desorption in undisturbed soil." Thesis, 1992. http://hdl.handle.net/1957/36308.
Full textYang, Sheng-Fu, and 楊昇府. "Sorption/Desorption and Biodegradation of Sulfonamide Antibiotics by Activated Sludge." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/98884610668449615306.
Full text國立臺灣大學
環境工程學研究所
100
Antibiotic were used widespread to protect humans and animals from illness and infection, throughout the world. The parent compound or their metabolites will be excreted by human beings and enter waste water treatment plants (WWTPs) through sewer system. To date, little has been quantified for the interactions, biodegradation and sorption, of sulfonamide antibiotics with activated sludge. Hence, three frequently occurring sulfonamide antibiotics including sulfamethoxazole (SMX), sulfadimethoxine (SDM), and sulfamonomethoxine (SMM) were selected to study sorption/desorption and biodegradation of antibiotics by the activated sludge process. Our objectives were to determine the distribution of sulfonamides in the aqueous and solid phases, the concentration changes of the compounds in both phases over time, and the sorption and biodegradation mechanisms contributed by the activated sludge for removal of the compounds. The distribution of antibiotics in municipal sewage sludge was also investigated in this research. The results of distribution of antibiotics in WWTPs activated and digested sludge showed the concentrations of penicillins in sewage sludge samples were found to be well below the limit of quantification (LOQ). This may be perhaps due penicillins prefer to hydrolyze in the water and are degraded to different products. Average concentrations of sulfamethoxazole, sulfamethazine, sulfamonomethoxine, sulfadimethoxine, erythromycin-H2O, tylosin, tetracycline, oxytetracycline and chlortetracycline in sewage sludge ranged between 2.56 and 56.6 μg/kg of dry weight. Experimental results in the presence of activated sludge with and without being subjected to NaN3 biocide showed that the antibiotic compounds were removed via sorption and biodegradation by the activated sludge, though biodegradation was inhibited in the first 12 h possibly due to competitive inhibition of xenobiotic oxidation by readily biodegradable substances. The affinity of sulfonamides to sterilized sludge was in the order of SDM>SMM>SMX. The sulfonamides existed predominantly as anions at the study pH of 6.8, which resulted in a low level of adsorption to the activated sludge. The adsorption/desorption isotherms were of a linear form, as well described by the Freundlich isotherm with the n value approximating unity. The linear distribution coefficients (Kd) were determined from batch equilibrium experiments with values of 28.6 ± 1.9, 55.7 ± 2.2, and 110.0 ± 4.6 mL/g for SMX, SMM, and SDM, respectively. SMX, SMM, and SDM desorb reversibly from the activated sludge leaving behind on the solids 0.9%, 1.6%, and 5.2% of the original sorption dose of 100 µg/L. In addition to apply biocide, an ultrasonic solvent extraction method was employed to quantify and delineate biosorption and biodegradation of three sulfonamide antibiotics in this work. All sulfonamides were removed completely over 11 – 13 d. Sorptive equilibrium was established well within the first few hours, followed by a lag period of 1-3 days before biodegradation was to deplete the antibiotic compounds linearly in the ensuing 10 days. Apparent zeroth-order rate constants were obtained by regression analysis of measured aqueous concentration vs. time profiles to a kinetic model accounting for sorption and biodegradation; they were 8.1, 7.9, and 7.7 µg/L/d for SDM, SMX, and SMM, respectively, at activated sludge concentration of 2.56 g/L. The results obtained in this study illustrate: 1. the sorbed antibiotics can be introduced into the environment if no further treatments were employed to remove them from the biomass; 2. the existence of antibiotics in municipal sewage sludge and the importance of concern about distribution of antibiotics in the environment when sewage sludge is reutilized in land application; 3. the measured kinetics implied that with typical hydraulic retention time (e.g. 6 h) provided by WWTP the removal of sulfonamide compounds from the wastewater during the activated sludge process would approximate 2 µg/L.
Wu, Bingyan. "Factors controlling alkylbenzene sorption and desorption in municipal solid waste." 2002. http://www.lib.ncsu.edu/theses/available/etd-07062002-190324/unrestricted/etd.pdf.
Full textHou, Chia-hui, and 侯佳蕙. "Sorption/desorption of Strontium and Cesium Cations on Clay colloids." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/kb8y8q.
Full text萬能科技大學
工程科技研究所
96
This study investigates the surface properties of clay particles and colloids of kaolinite, montmorillonite and ri-hsing bentonite. Moreover, the sorption/desorption of Cs+ and Sr2+ on the above three kinds of colloid in artificial buffered aqueous solutions were conducted to understand the fate of radioactive cations in the subsurface environment. The results show that the variation extents of specific surface area and cation exchange capacity depend on the kinds of clay particles and colloids. The sorption sites of montmorillonite colloid can be divided into two categories: sites of high energy that are effective sites for low cation concentration and sites of low energy that are only effective under high cation concentration. The fractions of the two kinds of sites vary with different pH conditions. When log [Cs+] or log [Sr2+] ranges among -3.5 to -1.5 mmol/L, the values of partition coefficient remain constant, which contributes to the bases of prediction for the Cs+ and Sr2+ sorption in subsurface environment. The sorbed Cs+ and Sr2+ could not completely desorb from colloids. X-ray defraction spectrums show that the sizes of clay lattice changed after sorption, which is worthy to investigate. The separation with centrifuge in this study was not satisfactorily to evaluate the rapid sorption rates.