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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Catalytic and Photocatalytic Removal of Contaminants of Emerging Concerns (CECs) and Per-/Polyfluoroalkyl Substances (PFAS) from Wastewater Effluents for Water Reuse Applications

Abdelraheem, Wael H.M. January 2020 (has links)
No description available.
162

PERFLUOROALKYL ACIDS AND OTHER TRACE ORGANICS IN WASTEDERIVED ORGANIC PRODUCTS: OCCURRENCE, LEACHABILITY, AND PLANT UPTAKE

Rooney Kim Lazcano (7038074) 14 August 2019 (has links)
<p>Waste-derived organic products are nutrient-rich materials often applied to agricultural land as a fertilizer to enhance agricultural production and soil quality. Commercially available biosolid-based products, which are sold and distributed in bags or bulk, are rapidly gaining popularity for urban and suburban use. Although biosolid-derived products have many benefits, they may contain trace organic contaminants such as per- and polyfluoroalkyl acids (PFAAs) and pharmaceutical and personal care products (PPCPs), in varying levels, depending on waste source composition. These organic compounds have been used in a variety of consumer and industrial products and are known to accumulate in biosolids due to their recalcitrance in conventional wastewater treatment processes. Thus, the application of commercially available biosolids-based products on urban and suburban gardens may lead to transfer and accumulation of organic contaminants into food crops, raising food safety concerns. Most studies to date have focused on municipal biosolids application on agricultural lands with very few studies focused on commercial products available for home and urban gardens. For the latter, the evaluations of bioavailability and subsequent plant uptake of organic contaminants from biosolids have also often been conducted by adding organic contaminants to the growing media (e.g., soil or hydroponic) at a concentration that greatly exceed environmentally relevant concentrations. Moreover, there are currently no studies evaluating leaching and plant uptake potential of contaminants from commercially available (e.g., local stores) biosolids. The research described in this dissertation 1) assessed the occurrence of PFAAs and representative PPCPs in commercially available biosolid-based products and their porewater concentrations in saturated media as a measure of bioavailability and leachability; 2) investigated how heat-treatment, composting, blending and thermal hydrolysis processes on biosolids to convert them to commercial biosolid-based products affect PFAA concentrations in the production of commercial biosolid-based product; and 3) assessed the bioavailability and plant uptake of PFAAs and targeted PPCPs by kale and turnips grown in soil-less potting media amended with Milorganite (a commercially available biosolids-based fertilizer product) at the recommended rate and four times the recommended rate.</p><p>The biosolid-based products displayed varying levels of organic contaminants. Higher PFAA concentrations were detected in biosolid-based products compared to nonbiosolid-based products. The common treatment processes used in taking biosolids to commercially available products were ineffective in reducing PFAA levels in the products except for blending with other essentially PFAA-free materials, thus served as a simple dilution. Porewater concentrations of PFAAs and PPCPs as an indicator of leachability and bioavailability were higher for the less hydrophobic compounds (e.g., short-chain PFAAs and diphenhydramine and carbamazepine with lower octanol-water partition coefficient). Leachability alone did not explain the observed plant uptake potential of PFAAs and PPCPs. With similar leachability and molecular weight/size between diphenhydramine and carbamazepine, higher uptake was observed with a positively charged compound (diphenhydramine compared to a neutral compound (carbamazepine). However, not all positively charged compounds were taken up by the plant. Azithromycin, a positively charged compound, had lower uptake than other contaminants which may be due to its large molecular size compared to diphenhydramine. Higher concentrations of miconazole, triclosan, and triclocarban were found in the biosolids-fertilizer; however, these compounds had low leachabilities and limited uptake by plants. Also, for PPCPs, the application rates of biosolid-based products did not necessarily correlate with the higher uptake and translocation of contaminants to the above-ground portion of plants. </p><p>This study provides an evaluation of commercially available waste-derived organic products under condition comparable to home and urban garden setting. Although biosolids-based products can serve as alternatives to synthetic fertilizers, they contain higher levels of trace organic contaminants than nonbiosolid-organic products. Common biosolids treatment processes are ineffective for reducing the levels of trace organic contaminants in biosolids, particularly for PFAAs. Thus, it is critical to control the sources contributing to the higher level of these contaminants in biosolids-based products. Also, regulations (e.g., triclosan and triclocarban) and replacements (e.g., longer-chain PFAAs to short-chain PFAAs) of persistent trace organic chemicals have led to a reduction in their levels in biosolids-based products. Although longer chain PFAAs are more likely to bioaccumulate and persistent than the replacement short-chain alternatives, the current study has shown that the short-chain PFAAs are more readily taken up to edible parts of plants than longer-chain PFAAs even when applying at the recommended fertilizer rate. Thus, the current movement to replace longer chain PFAAs with short chains has the potential to result in higher total PFAA concentrations being bioavailable for plant uptake, thus increasing the risk of food contamination by PFAAs. </p>
163

Efeito tóxico da cafeína sobre o ciclo de vida de Chironomus sancticaroli (Chironomidae, Diptera) e Daphnia magna (Daphniidae, Cladocera) / Caffeine toxic effect on Chironomus sancticaroli (Diptera: Chironomidae) life cycle and Daphnia magna (Cladocera: Daphnidae)

Bernegossi, Aline Christine 02 April 2019 (has links)
A cafeína está presente no cotidiano humano desde o tradicional café até como constituinte de medicamentos, estimulantes, chás, chocolate entre outros produtos alimentícios. Essa substância é considerada um contaminante orgânico emergente provindo de águas residuárias não tratadas. Sua presença nos corpos hídricos vem sendo documentada em baixas concentrações, desde &eta;g.L-1 até &#181;g.L-1 e os efeitos dessas concentrações nos organismos aquáticos ainda não foram efetivamente investigados. Com o objetivo de avaliar os efeitos tóxicos da cafeína em concentrações comumentemente encontradas em corpos hídricos, foram realizados testes de ecotoxicidade aguda e crônica com os organismos-teste Chironomus sancticaroli e Daphnia magna e intergeracional com C. sancticaroli, com enfoque em respostas biológicas de mortalidade, imobilidade, crescimento, desenvolvimento e reprodução. Como resultado, a cafeína não apresentou toxicidade aguda no teste de curta duração realizado para D. magna e C. sancticaroli. Foi observado efeito de toxicidade crônica da cafeína, havendo interferência no desenvolvimento das larvas de Chironomus principalmente na concentração de 200 &#181;g.L-1 e no crescimento e reprodução de D. magna, na qual foi observada indução na produção de neonatos e desaceleração para o desenvolvimento do organismo (retardo no processo de ecdise). No teste intergeracional, foram observadas mudanças nos padrões de desenvolvimento larval. Os resultados demonstram que a cafeína, em concentrações ambientalmente detectadas, pode causar pequenas alterações no ciclo de vida dos organismos, como por exemplo, alterações no tamanho das asas das fêmeas e no comprimento do corpo das larvas de C. sancticaroli. Recomendam-se o uso de técnicas biomoleculares para avaliar as respostas metabólicas dos organismos quando exposto à cafeína em baixas concentrações. / Caffeine is present in human daily life either as traditional coffee or constituent of medicines, stimulants, teas, chocolate, among other products. This substance is an emerging organic contaminant from untreated wastewater. Its presence in aquatic systems has been documented at low concentrations, from &eta;g.L-1 to &#181;g.L-1 and the effects of these concentrations on aquatic organisms have not yet been effectively investigated. In order to evaluate the toxic effects of caffeine, at concentrations usually found in aquatic systems, acute and chronic ecotoxicological tests were performed with Chironomus sancticaroli and Daphnia magna and, an intergenerational with C. sancticaroli, focusing on biological responses of mortality, immobility, growth, development and reproduction. As a result, caffeine did not present acute toxicity in the shor-term test performed for D. magna and C. sancticaroli. Chronic toxicity of caffeine was observed, with interference in the Chironomus larvae development, mainly in the concentration of 200 &#181;g.L-1, and in the growth and reproduction of D. magna, in which it was observed presence of induction in the production of neonates and deceleration to the development of the organism (delay in the process of ecdysis). In intergeneration test, changes in the larval developmental patterns were observed. In intergenerational testing, changes in larval developmental patterns were observed. The results demonstrate that caffeine, in concentrations detected environmentally, can cause small influences in the organism\'s life cycle of the, for example, changes in the size of the wings of the females and in the length of the body of the larvae of C. sancticaroli. The use of biomolecular techniques to evaluate the metabolic responses of organisms when exposed to caffeine at low concentrations is recommended.
164

Detecção e quantificação de alguns elementos químicos inorgânicos em sangue e tecidos de tartarugas-verdes - Chelonia mydas (Linnaeus, 1758) - da costa brasileira: possível correlação com a fibropapilomatose / Detection and quantification of selected inorganic chemical elements in blood and tissue samples from green turtles Chelonia mydas (Linnaeus, 1758) from the Brazilian coast: possible correlation with fibropapillomatosis

Prioste, Fabiola Eloisa Setim 30 March 2016 (has links)
A fibropapilomatose é uma doença multifatorial em tartarugas marinhas caracterizada por tumores cutâneos benignos. O surgimento da doença é atribuído à associação do Chelonid herpesvirus 5 (ChHV-5), à genética e à fatores ambientais. A tartaruga-verde (Chelonia mydas) é a espécie mais acometida pela doença, sendo esta uma das maiores ameaças à sua sobrevivência. Este estudo teve por objetivo detectar e mensurar seis elementos químicos inorgânicos: Arsênio (As), Cádmio (Cd), Chumbo (Pb), Selênio (Se), Zinco (Zn) e Mercúrio (Hg) em sangue de tartarugas-verdes (Chelonia mydas) capturadas vivas e tecidos (baço, rins, fígado, glândula de sal, musculatura esquelética e tecido ósseo) de necropsias realizadas em indivíduos encontrados mortos. Quatro localidades da costa brasileira foram amostradas: Almofala CE; Fernando de Noronha PE; Vitória ES e Ubatuba SP. Foram colhidas 233 amostras de sangue e 488 amostras de tecido entre março de 2012 e outubro de 2015. As amostras foram analisadas em um espectrômetro de massas com plasma indutivamente acoplado (ICP-MS). Os resultados das análises de sangue apontaram Fernando de Noronha como um possível grupo controle para estudos desta ordem. As e Se foram encontrados em Fernando de Noronha em níveis séricos muito baixos. Tartarugas-verdes das outras três localidades estudadas apresentaram uma diminuição desses elementos quando com sinais de FP, ao mesmo tempo em que apresentaram concentrações maiores de algum elemento químico tóxico, como Pb e Hg. Quanto aos resultados obtidos com amostras teciduais, as tartarugas-verdes com sinais de FP apresentam menores concentrações de As e Se em todos os órgãos analisados, ao mesmo tempo que apresentam maior concentração de Pb em fígado, rins e ossos / Fibropapillomatosis is a multifactorial disease of sea turtles characterized by benign cutaneous tumors. The development of this disease is attributed to the association of Chelonid herpesvirus 5 (ChHV-5), to genetics and environmental factors. The green turtle (Chelonia mydas) is the species most affected by fibropapillomatosis, one of the biggest threats to the survival. The aim of this study was to detect and quantify six inorganic chemical elements: Arsenic (As), Cadmium (Cd), Lead (Pb), Selenium (Se), Zinc (Zn) and Mercury (Hg) in blood samples of green turtles trapped alive, and tissue samples (spleen, kidneys, liver, salt glands, skeletal muscles and bone tissue) collected during necropsies of carcasses. The samples was collected in four different locations of the Brazilian coast: Almofala Ceará; Fernando de Noronha Pernambuco; Vitória Espírito Santo e Ubatuba São Paulo. We collected 233 blood samples and 488 tissue samples between March 2012 and October 2015. Samples were analysed by inductively coupled plasma mass spectrometry (ICP-MS) techniques. The results of the blood analyses indicated Fernando de Noronha as a possible control group for studies of this nature. As and Se were observed in Pernambuco (Fernando de Noronha) in very low blood levels. Green turtles from the three other locations presented decreased levels of the same elements in cases with signs of FP, while presenting higher concentrations of some of the toxic chemical elements, such as Pb and Hg. The results obtained from tissue samples showed that green turtles with signs of FP present lower As and Se in all analysed organs, and higher [Pb] in liver, kidneys and bone tissues
165

Avaliação da técnica de eletroosmose na remoção de contaminante orgânico em meios particulados. / Eletrochemical techniques for particulate system decontamination treatments.

Silva, Eliandro Rezende da 07 June 2001 (has links)
O tratamento por técnicas eletroquímicas é provavelmente uma das metodologias mais prometedoras na descontaminação de sistemas particulados, sendo capaz da remoção, total ou parcial, de contaminantes como metais pesados, radionuclídeos, orgânicos e inorgânicos. Pelo uso de uma diferença de potencial elétrico em correntes baixas aplicadas através de pares de eletrodos, os contaminantes são movidos sob a ação do campo elétrico. A extração de impurezas pelo método eletrocinético é baseada na suposição que as moléculas estejam ou sejam evoluídos para a fase liquida. O ciclo completo envolve a adsorção, o transporte, a captação, e a remoção do contaminante dos meios porosos. Neste trabalho avaliou-se o emprego da técnica de eletroosmose na remoção de fenol em meios líquidos e porosos. O fenol foi escolhido por ser um composto altamente tóxico, proveniente de refinarias de óleos, industrias de tintas e principalmente pesticidas. Para a validação do processo em escala de laboratório, foi confeccionada uma célula eletroquímica para um volume de 700 cm3, com eletrodos de titânio. A concentração de fenol utilizada para este experimento foi constante de 11 mM. Água destilada, areia, pós de vidro e solo foram classificados, caracterizados e selecionados como meios porosos experimentais. As aplicações das cargas variaram de O a 120-140-240 minutos, sendo que o mapeamento do pH indicou eletromigração de espécies em todos os sistemas. Na eletroosmose temos o arraste das moléculas de fenol em direção ao catodo simultâneo à eletrólise da água, cujas concentrações relativas de contaminante foram avaliadas por espectroscopia de UV-Vis. A montagem dispõe de um reservatório para coleta de produtos de reação em cada eletrodo sendo possível a remoção do íon fenólico migrado. O processo apresentou eficiências variando de 40% a 60% na extração, dependendo das características do meio poroso. De um modo geral a técnica apresentou-se ecologicamente viável e econômica, como procedimento de remediação de solos e sistemas particulados diversos. / The use of electrochemical techniques is probably one of most promising technology for particulate system decontamination treatments. This methodology appears as able to remove heavy metals, radionucletides and organic and inorganic contaminations. By using an electric potential difference with low currents intensities through electrodes, the contaminants in the porous medium are dragged under electric field action. The contaminant removal is base on the supposition that the impurities are in solution or elute to the liquid phase. The whole cycle involves adsorption, transport, collection and removal of contaminants from the medium. In this work it was studied the use of the electroosmosis technique for removal of phenol from porous and aqueous medium. Phenol was chose because of its high toxicity and the regularly use in oil refineries, ink industries and pesticides. To validate the process, in laboratorial scale, an electrochemical cell of 700 cm3 volume, with titanium electrodes was constructed. The phenol concentration was 11 mM. Distillated water, sand, glass powder and sample of soil were classified, characterized and selected to constitute the porous media. The charge application time varied from 120 to 140 to 240 minutes and the pH mapping showed migration effect in ali of the systems. In the electroosmosis process we have the molecules of phenol dragged towards the cathode simultaneously to the water electrolysis. The relative concentrations of phenol were evaluated by UV-Vis spectroscopy. In the experimental setup a reservoir in each electrode was assembled in order to collect the reaction products. The process efficiencies are in a range from 40% to 60%, dependent of the porous medium characteristics. In a broad sense, the technique showed feasible as an economic and ecological procedure for soil and particulate system remediation.
166

Adsorção de fármacos em carvão ativado : processo em batelada, leito fixo e modelagem das curvas de ruptura

Franco, Marcela Andrea Espina de January 2018 (has links)
O presente trabalho estuda a remoção dos fármacos amoxicilina (AMX), diclofenaco sódico (DCF) e paracetamol (PAR) em solução aquosa pelos processos de adsorção em batelada e coluna de leito fixo utilizando o carvão ativado granulado (CAG) como adsorvente. Os experimentos foram realizados para cada fármaco de forma independente. Na adsorção em batelada foram avaliadas as influências do pH (2 – 10), concentração de adsorvente (5 – 20 g L-1) e tempo de contato (5 – 350 min). Foi realizada a investigação da cinética de adsorção e também do equilíbrio de adsorção através de isotermas nas temperaturas de 25, 35 e 45 ºC. A adsorção em leito fixo foi estudada através de planejamentos experimentais, onde foram avaliados os efeitos da concentração inicial do poluente (C0: 20 – 100 mg L-1), massa do leito (W: 0,5 – 1,5 g) e vazão (Q: 3 – 5 mL min-1) sobre o tempo de saturação (tsat) e a quantidade adsorvida (qsat). Os modelos de Thomas, Bohart-Adams e Yan, além de um modelo desenvolvido no software EMSO foram utilizados para análise das curvas de ruptura. O CAG utilizado apresentou área BET de 463 m² g-1 e maior volume de microporos, de 0,20 cm³ g-1. Os experimentos em batelada mostraram que o pH não teve influência significativa sobre a remoção dos três fármacos. O equilíbrio de adsorção da AMX e do DCF foi atingido após 150 min e do PAR após 180 min. O modelo de PSO foi o que melhor representou a cinética de adsorção dos três fármacos. A isoterma de Langmuir descreveu o equilíbrio da AMX a 25 e 35 ºC, e o modelo de Sips a 45 ºC. Já a adsorção do DCF foi representada pela isoterma de Freundlich e o PAR pela de Redlich-Peterson. O estudo termodinâmico indicou que a adsorção dos três fármacos foi espontânea e favorável, além de aumentar com o aumento da temperatura. Na adsorção em leito fixo, foi observado menores valores de tsat com o aumento de C0 e de Q e diminuição de W. Foi verificado que qsat aumentou com o aumento de C0 e diminuição da Q para o planejamento do PAR, onde essa variável foi significativa. Já o aumento de W aumentou qsat no planejamento do PAR e diminuiu nos casos da AMX e DCF. A AMX foi o poluente que apresentou os menores tempos de saturação, seguido do DCF e do PAR, na adsorção em leito fixo. Foi constatado que o modelo de Yan foi o que melhor reproduziu o comportamento das curvas de ruptura para os três fármacos, na comparação com os outros modelos analíticos e com o modelo numérico proposto no software EMSO. De forma geral, foi verificado que os processos de adsorção tanto em batelada quanto em leito fixo apresentam potencial de aplicação como alternativa de tratamento avançado de água e efluentes que contenham fármacos. / The present work studies the removal of amoxicillin (AMX), sodium diclofenac (DCF), and paracetamol (PAR) from water by adsorption onto granular activated carbon in batch process and fixed bed column. Batch adsorption experiments were performed to evaluate the influence of pH (2 – 10), adsorbent concentration (5 – 20 g L-1) and contact time (5 – 350 min). Pseudo-first order, pseudo-second order and intraparticle diffusion models were evaluated in the kinetics investigation. Equilibrium adsorption was investigated using Langmuir, Freundlich, Sips and Redlich-Peterson equations. Fixed bed adsorption was studied through experimental design to evaluate initial contaminant concentration (C0, 20 – 100 mg L-1), amount of adsorbent (W, 0.5 – 1.5 g) and feed flow rate (Q, 3 – 5 mL min-1) effects. The analytical models of Thomas, Bohart-Adams and Yan were selected to investigate the breakthrough curves behavior. In addition, a numerical model was developed and solved using EMSO software. The granular activated carbon (GAC) used had BET surface area of 463 m² g-1 and volume of 0.20 cm³ g-1 of micropores. The pH had no significant effect on the adsorption removal of the three drugs. Adsorption equilibrium of AMX and DCF was reached after 150 min and 180 min for PAR. Pseudo second order model best represented kinetic adsorption of the three compounds. At best conditions in batch process, adsorbent concentration was 12.5 g L-1 for AMX and DCF and 10 g L-1 for PAR. Langmuir isotherm best described AMX adsorption equilibrium at 25 and 35 ºC, and Sips model at 45 ºC. DCF and PAR adsorption followed the Freundlich isotherm and Redlich-Peterson model, respectively. Thermodynamic study indicated that the three drugs adsorption were spontaneous and favorable processes. In addition, adsorption increased at higher temperatures. In fixed bed adsorption experiments, saturation time (tsat) decreased with the increase of initial concentration and flow rate for both drugs. W had positive effect on tsat. The amount adsorbed (qsat) was enhanced at higher C0 and lower Q. qsat was higher at higher Q for AMX and DCF and lower Q for PAR adsorption. Yan model best reproduced breakthrough curves behavior for all drugs among the analytical models and the numerical model developed on EMSO software. Thus, adsorption processes in batch mode and fixed bed column showed to be effective for the removal of drugs of different therapeutic classes from water.
167

Degradação do antibiótico tetraciclina por vários processos em mistura salina / Degradation of antibiotic tetracycline by various processes in saline medium

Gul, Saima 25 April 2014 (has links)
A degradação de antibiótico tetraciclina (TeC) foi avaliada por vários processos a saber, eletroquímico, eletroquímico foto-assistido, Fenton e foto-Fenton. Uma vez que este tipo de antibiótico é excretado principalmente pelo sistema urinário, o meio selecionado foi uma mistura de sais predominantes na composição de urina, a qual apresenta alta concentração de diferentes íons, especialmente íons cloretos. As degradações eletroquímica e eletroquímica foto-assistida foram realizadas em uma célula de fluxo do tipo filtro-prensa, usando um ânodo dimensionalmente estável comercial com composição nominal Ti/Ru0,3Ti0,7O2. O decaimento da concentração do TeC foi determinado por cromatografia líquida de alta eficiência (CLAE) e a remoção da carga orgânica por análise de carbono orgânico total (COT). Os processos de degradação eletroquímica e eletroquímica foto-assistido utilizaram densidades de correntes de 20 a 40 mA cm-2 e concentração inicial de TeC de 200 mg L-1. Aplicando 30 mA cm-2, após duas horas a remoção de TeC foi de 91% e 98%, utilizando processo eletroquímico sem e com foto- assistência, respectivamente. A remoção de COT foi incompleta com um máximo de 17%. A fim de comparar o efeito da mistura salina sobre a degradação de TeC, as eletrólises também foram realizadas em NaCl 0,1 mol L-1, onde foi obtida degradação rápida e completa (100%) em ambos os processos, a remoção de COT também foi melhorada (~29%). A degradação de TeC obedeceu uma cinética de pseudo-primeira ordem. A degradação também foi avaliada utilizando os processos Fenton e foto-Fenton na mesma mistura salina variando a concentração inicial de H2O2 (50-150 mg L-1) e de Fe2+ (2,5-15 mg L-1). A concentração inicial de Fe2+ e H2O2 tem uma influência maior sobre a degradação durante ambos os processos. Durante o processo Fenton, sob condições otimizadas, a TeC foi degradada >96%, sendo 57% a redução de COT correspondente, enquanto em meio de NaCl ocorreu a remoção de 99% e redução de COT de 41%. Um ligeiro decaimento foi observado utilizando o processo foto-Fenton devido à influência de íons presentes no meio. Os intermediários de degradação também foram identificados por CLAE acoplado a espectrometria de massa durante os processos Fenton e foto-Fenton, sendo então proposta uma sequência reacional de degradação da TeC . / The degradation of antibiotics tetracycline (TeC) was evaluated by various processes such as electrochemical, photo-assisted electrochemical, Fenton and photo-Fenton. Since this type of antibiotic is excreted mainly by urinary system, the selected medium was a mixture of salts prevailing in composition of urine, which has high concentration of different ions, especially chloride ions. The electrochemical and photo-assisted electrochemical degradations were performed in a filter press type flow cell using a dimensionally stable anode with nominal composition of Ti/Ru0.3Ti0.7O2. The decrease in TeC concentration was analyzed by high performance liquid chromatography and total organic carbon analysis. The electrochemical and photo-assisted electrochemical degradation was performed at current densities of 20 to 40 mA cm-2 and initial TeC concentration of 200 mg L-1. At a current density of 30 mA cm-2,91% and 98% TeC was removed after 2 hours, during electrochemical and photo-assisted electrochemical processes respectively. The TOC removal was incomplete with maximum of 17%. In order to compare the TeC degradation in saline medium, electrolysis was also carried out in 0.1 mol L-1 NaCl, where fast and complete (100%) degradation was observed in both processes and TOC removal was also improved (~29 %). The degradation of TeC followed pseudo-first order kinetics. Fenton and Photo-Fenton process was also evaluated for the degradation of TeC in similar saline medium varying the initial concentration of H2O2 (50_150 mg L-1) and Fe2+ (2.5-15 mg L-1). The initial concentration of Fe2+ and H2O2 has a high influence upon TeC degradation during both processes. During Fenton process under optimized conditions, >96% of TeC was degraded and 57% TOC was removed. However in NaCl medium, 99% degradation 41% TOC was obtained. The degradation was slightly decreased during photo-Fenton process due to the influence of ions in the medium. The degradation Intermediates were also identified by HPLC coupled with mass spectrometer and proposed a reaction sequence for the degradation of TeC.
168

Towards A Better Understanding of Contaminant Fate in Plastic Plumbing Systems and Their Remediation

Xiangning Huang (5929781) 17 January 2019 (has links)
<p><a>This dissertation focused on better understanding the fundamental processes that control organic and inorganic contaminant interaction with plastic plumbing pipes. Plastic pipes are increasingly being installed for drinking water plumbing, but their role in affecting drinking water quality has received little study. It is well-known that plastic pipes can sorb and release organic contaminants and be difficult to decontaminate. Several problems were identified in the literature and through discussions with industry: (1) Past guidance issued to communities affected by petroleum contaminated water does not seem to specifically consider plastic plumbing pipe remediation, (2) investigators have also identified heavy metals can accumulate on pipe inner walls, (3) Others have proposed certain heavy metals can catalyze plastic water pipe degradation, (4) No nondestructive cleaning methods were found for removing metal scales from plastic pipes.</a> These topics were a basis for studies conducted because lack of information inhibits greater protection of public health, safety, and welfare.</p> This dissertation involved the application of knowledge and techniques from the environmental engineering and science, polymer engineering, and material science disciplines. Chapter 1 focused on the response of copper and plastic pipes (i.e., chlorinated polyvinylchloride (cPVC), high-density polyethylene (HDPE), crosslinked polyethylene (PEX)) exposed to petroleum contaminated drinking water. Bench-scale results revealed that pipe rinsing followed by a single 3 day water stagnation period removed target monoaromatic hydrocarbons (MAH) from copper pipes, but much longer (<u>></u>15 days) time was required for decontaminating cPVC, HDPC, and PEX pipes. Benzene, trimethylbenzene and polynuclear aromatic hydrocarbons, some of which are not typically considered in drinking water contamination investigations, were found desorbed into clean drinking water from pipes. Future plumbing decontamination guidance should consider the conditions necessary for plastic pipe remediation. Chapter 2 describes the influence of drinking water conditions on heavy metal contaminant – low density polyethylene (LDPE) pellet surface interactions. Mixed metal drinking water solutions were applied and contained Cu, Fe, Mn, Pb and Zn at 30 µg/L. LDPE was selected as the model polymer because of its prior use for piping in Europe, use in bench-scale studies by others, and similarity to products used for the manufacture of more complex materials in the USA (HDPE, PEX). As expected, metal loadings were about 5 times greater for aged LDPE pellets suspended in solution compared to new LDPE pellets. This difference was attributed to the aged plastic surfaces having oxygen containing functional groups, increased surface area, and enhanced hydrophilicity. Metal loading was lower at pH >9.5 and in the presence of dissolved organic contaminants. The presence of free chlorine and corrosion inhibitor also decreased metal adsorption onto LDPE pellets. These factors likely enabled metal precipitation thereby not allowing metal species to adsorb to LDPE pellets suspended in water. XPS results showed deposited metals (i.e., Cu, Pb, Zn) primarily consisted of hydroxides and oxides. To further understand heavy metal – plastic pipe interactions, Chapter 3 involved the use of metal and plastic pipe rigs and exhumed PEX plumbing pipes. Exhumed cold and hot water PEX pipes contained a noticeable amount of heavy metals (i.e., most abundant metals were 2049 mg/m<sup>2</sup> Fe, 400 mg/m<sup>2</sup> Ca, 438 mg/m<sup>2</sup> Zn and 150 mg/m<sup>2</sup> P). Metal release and deposition onto PEX pipe was examined using bench-scale pipe rigs that contained new PEX pipe, brass valves, and copper pipe. Two water matrices (pH 4 and 7.5) and two temperatures (23<sup>o</sup>C and 55<sup>o</sup>C) were explored. The pH 4 water often accelerated metal leaching from brass valves, and a greater amount of heavy metals deposited on PEX pipes at high water pH and temperature (pH 4 and 55<sup>o</sup>C) conditions. Oxygen containing functional groups were detected on PEX pipes connected to a brass valve or a brass valve combined copper pipe, but were not found on PEX pipe only (controls) samples, indicating that certain configurations may facilitate plastic pipe degradation. The last chapter describes the ability of a new lignin derived ligand to remove metal deposits from exhumed PEX plumbing pipes. When the ligand concentration was ≥ 5mM, more than 95% of sorbed metals (i.e., Cu, Fe, Mn, Pb and Zn) were removed. The ligand favored certain metals over others (Cu > Zn > Fe > Mn > Pb) and heavy metal removal mechanisms were proposed. This dissertation provides insights into the role of plastic pipes on drinking water quality. As plastic pipes continue to be installed, it is in the interest of public health, welfare, and safety to understand their role in positively and negatively affecting drinking water safety.
169

Occurrence, fate and effects of selected pharmaceuticals in sewage treatment plants.

January 2011 (has links)
Guan, Lijie. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 139-161). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Table of contents --- p.vii / List of Figures --- p.X / List of Tables --- p.xiii / Abbreviations --- p.xiv / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Source and Fate of Pharmaceuticals in the Environment --- p.1 / Chapter 1.2 --- Occurrence of Pharmaceuticals --- p.2 / Chapter 1.2.1 --- Wastewater --- p.2 / Chapter 1.2.2 --- Sewage sludge and soil --- p.5 / Chapter 1.2.3 --- "Surface water, ground water and seawater" --- p.6 / Chapter 1.2.4 --- Drinking water --- p.9 / Chapter 1.3 --- Effects on the Environment --- p.11 / Chapter 1.3.1 --- Antibiotic resistance --- p.11 / Chapter 1.3.2 --- Ecotoxicity on the aquatic organisms --- p.14 / Chapter 1.4 --- Removal in the Environment --- p.19 / Chapter 1.4.1 --- Adsorption --- p.20 / Chapter 1.4.2 --- Photodegradation and hydrolysis --- p.22 / Chapter 1.4.3 --- Biodegradation --- p.23 / Chapter 1.5 --- Analytical Method of Pharmaceuticals in Environmental Samples --- p.25 / Chapter 1.5.1 --- Solid-phase extraction --- p.25 / Chapter 1.5.2 --- Liquid chromatography mass spectrometry --- p.30 / Chapter 1.6 --- Objectives and Outline of Thesis --- p.33 / Chapter 2 --- OCCURRENCE AND FATE OF SELECTED PHARMCEUTICALS IN STPS --- p.35 / Chapter 2.1 --- Introduction --- p.35 / Chapter 2.2 --- Materials and Methods --- p.36 / Chapter 2.2.1 --- Choice of pharmaceuticals for study --- p.36 / Chapter 2.2.2 --- Description of sewage treatment plants (STPs) --- p.41 / Chapter 2.2.3 --- Experimental approach --- p.49 / Chapter 2.3 --- Results and Discussion --- p.55 / Chapter 2.3.1 --- Occurrence of azithromycin --- p.55 / Chapter 2.3.2 --- Fate of azithromycin --- p.59 / Chapter 2.3.3 --- Occurrence of erythromycin --- p.63 / Chapter 2.3.4 --- Fate of erythromycin --- p.67 / Chapter 2.3.5 --- Occurrence of roxithromycin --- p.70 / Chapter 2.3.6 --- Fate of roxithromycin --- p.74 / Chapter 2.3.7 --- Occurrence of atenolol --- p.75 / Chapter 2.3.8 --- Fate of atenolol --- p.79 / Chapter 2.3.9 --- Occurrence of simvastatin --- p.81 / Chapter 2.3.10 --- Fate of simvastatin --- p.84 / Chapter 2.3.11 --- Fate of pharmaceuticals during different treatment process --- p.85 / Chapter 2.3.12 --- Contribution of industrial (manufacturing) plants to STPs --- p.87 / Chapter 2.3.13 --- Seasonal variation --- p.87 / Chapter 2.4 --- Summary --- p.90 / Chapter 3 --- EFFECTS OF PHARMACEUTICALS ON ACTIVATED SLUDGE BACTERIA --- p.91 / Chapter 3.1 --- Introduction --- p.91 / Chapter 3.2 --- Materials and Methods --- p.92 / Chapter 3.2.1 --- Growth inhibition test --- p.92 / Chapter 3.2.2 --- Nitrification inhibition test --- p.94 / Chapter 3.3 --- Results and Discussion --- p.96 / Chapter 3.3.1 --- Growth inhibition of activated sludge bacteria --- p.96 / Chapter 3.3.2 --- Inhibition of nitrifying bacteria --- p.102 / Chapter 4 --- BIODEGRADATION PATHWAYS OF FOUR PHARMACEUTICALS --- p.106 / Chapter 4.1 --- Introduction --- p.106 / Chapter 4.2 --- Materials and Methods --- p.107 / Chapter 4.2.1 --- Test procedures --- p.107 / Chapter 4.2.2 --- Detection method --- p.108 / Chapter 4.3 --- Results and Discussion --- p.109 / Chapter 4.3.1 --- Degradation of atenolol --- p.109 / Chapter 4.3.2 --- Degradation of azithromycin --- p.117 / Chapter 4.3.3 --- Degradation of erythromycin --- p.129 / Chapter 4.3.4 --- Degradation of roxithromycin --- p.133 / Chapter 4.4 --- Summary --- p.134 / Chapter 5 --- GENERAL CONCLUSIONS --- p.136 / References --- p.139
170

Avaliação da contaminação por metais em solos impactados pela disposição de rejeitos industriais: estudo de caso – CENTRES (Queimados, RJ)

Santos, Maria Carla Barreto 21 September 2017 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-09-21T15:44:28Z No. of bitstreams: 1 Dissertação BancaBiblioteca 2.pdf: 4027206 bytes, checksum: 021859ae1f610282130511ff3c163b0f (MD5) / Made available in DSpace on 2017-09-21T15:44:28Z (GMT). No. of bitstreams: 1 Dissertação BancaBiblioteca 2.pdf: 4027206 bytes, checksum: 021859ae1f610282130511ff3c163b0f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O Centro Tecnológico de Resíduos (CENTRES) é um exemplo de passivo ambiental localizado no município de Queimados, RJ. Neste local, toneladas de resíduos industriais foram armazenadas sem nenhum critério ou fiscalização. Os recipientes contendo rejeitos químicos sofreram vazamentos e ocasionaram o contato de metais tóxicos com o solo. Metais tóxicos no solo associam-se a diversos componentes orgânicos e inorgânicos, apresentando-se em diversas formas químicas que podem interferir na mobilidade destes metais no solo Este estudo visa observar a presença e a mobilidade dos metais Cádmio, Cromo, Cobre, Níquel, Chumbo e Zinco no solo do CENTRES. Para tal foram realizadas análises de caracterização do solo e extrações pseudototais e sequenciais em amostras de sete diferentes pontos da localidade mencionada. As análises físicas do solo foram realizadas segundo a metodologia da EMBRAPA (1997). As análises químicas para avaliação da concentração dos metais no solo e para fracionamento geoquímico foram realizadas com os métodos US EPA3051 e BCR, respectivamente. No método BCR as frações solúveis em ácido, redutível e oxidável, e residual são obtidas através de ataques químicos sucessivos. As análises de caracterização física mostraram um solo predominantemente franco-argiloarenoso, com pH variando entre 4,2 e 6,9 e baixa capacidade de troca de cátions. As análises de concentração de contaminantes mostraram solos com valores acima da recomendação sugerida pela Companhia de Tecnologia de Saneamento Ambiental (CETESB, 2005) e pela Resolução CONAMA (2009), com destaque para os pontos P5 e P6, que apresentaram altas concentrações de contaminantes. Dos sete pontos analisados, quatro estavam classificados como solos Classe 3 ou Classe 4 de acordo com CONAMA (2009), o que demonstra a gravidade da contaminação da área. O Fracionamento Geoquímico das amostras mostrou que em P1, P2, P5 e P6 os metais que apresentam maiores concentrações, encontram-se também na Fração Trocável do solo, ou seja, a Fração mais disponível ao ambiente. Em contrapartida, Zinco e Chumbo apresentaram altas concentrações na Fase Residual do solo. / Centro de Tecnológico de Resíduos (CENTRES) is an example of environmental liabilities in the town of Queimados, RJ. In this place, tons of industrial waste were stored without any discretion or supervision. The containers of chemical waste have suffered and caused leaks of toxic metals contact with the ground. Toxic metals in soil are associated with various organic and inorganic components, performing in various chemical forms that can interfere with the mobility of these metals in the soil. This study aims to observe the presence and mobility of metals Cadmium, Chromium, Copper, Nickel, Lead and zinc in soil from the center. For this analysis were performed to characterize the soil and pseudototais extractions and sequential samples from seven different points in the locality mentioned. The physical analysis of soil were performed using the methodology of EMBRAPA (1997). The chemical analysis to assess the concentration of metals in soil and geochemical fractionation methods were performed with the US EPA3051 and BCR, respectively. In BCR fractions soluble in acid, reducible and oxidizable, and residual are obtained by successive chemical attacks. The analysis of physical characterization showed a sandy-clay loam, with pH ranging between 4.2 and 6.9 and low cation exchange capacity. The analysis showed the concentration of contaminants in soil above the recommended values suggested by the Companhia de Tecnologia de Saneamento Ambiental (CETESB, 2005) and by CONAMA (2009), highlighting the points P5 and P6, which showed high concentrations of contaminants in area. Of the seven points analyzed, four were classified as Class 3 soils or Class 4 according to CONAMA (2009). The Geochemical fractionation of samples showed that in P1, P2, P5 and P6, the metals that have higher concentrations are also found in the exchangeable fraction of soil, the fraction most available to the environment. In contrast, zinc and lead concentrations were high in Residual Phase soil.

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