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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.
71

Characteristics and mechanisms of atrazine sorption to biochar for land remediation

McMillan, Oliver January 2018 (has links)
Contaminated land is a widespread, global issue affecting millions of people. Atrazine is a commonly used herbicide which often contaminates groundwater and drinking water supplies and is associated with adverse health outcomes. Biochar is the solid product of pyrolysis and is associated with several environmental benefits. It may be an effective remediation tool when used as a soil amendment. This thesis investigates the mechanisms through which biochar can immobilise atrazine, and the implications of the mechanisms for remediating contaminated land. Nine biochar samples were obtained from the United Kingdom Biochar Research Centre , which were produced from softwood pellets (SWP), wheat straw pellets (WSP), miscanthus straw pellets (MSP), rice husk (RH) and oil seed rape (OSR) each at pyrolysis temperatures of 550°C and 700°C (excluding OSR at 700°C). The sorption mechanisms controlling atrazine sorption to these biochars were determined through various characterisation methods and batch sorption experiments. The sorption tests showed that sorption to each of the standard biochars occurs via multiple simultaneously occurring mechanisms, which are each promoted under certain conditions. Studies investigating sorption kinetics, isotherms and interactions with humic acids showed that for all biochars in this study, pore filling was a significant process through which atrazine is transported to adsorption sites, although poor intraparticle diffusion for softwood and oil seed rape biochars can prevent efficient transport. Wheat straw and rice husk biochars showed effective pore diffusion, resulting in high sorption capacities. Partitioning was associated with poor remediation outcomes and was significant to softwood biochars, although adsorption dominated overall sorption for all other biochars. pH was shown to significantly influence the occurrence of various sorption mechanisms. At low pH values, most biochars showed evidence of electrostatic repulsion between positive atrazine species and the positively charged biochar surface. At intermediate pH values, all biochars showed strong hydrogen bonding between H+ groups on the surface of the biochar and atrazine. A meta-analysis of previous relevant studies provided further evidence for hydrogen bonding of atrazine to biochar and showed that hydrophobic effects likely play little role in adsorption after accounting for the effects of surface area. Varying contributions of π-π EDA interactions, hydrogen bonding involving biochar O- groups, and interactions with ash minerals resulted in different sorption profiles for each biochar at high pH values. In order to further determine the mechanisms controlling sorption at high pH, surface compositions of SWP550, RH700 and OSR550 biochars were modified using hydrofluoric acid. Modification with hydrofluoric acid successfully removed the ash contents of rice husk and oil seed rape biochars and reduced atrazine removal at high pH values. This suggested that the ash fraction increases atrazine removal at high pH through complexation or catalytic hydrolysis. The roles of the various mechanisms are related to remediation outcomes in a novel manner allowing for the improved design of biochar for environmental remediation.
72

Ocorrência e comportamento ambiental de resíduos de antibióticos de uso veterinário / Occurrence and environmental behavior of residues of veterinary antibiotics

Leal, Rafael Marques Pereira 28 May 2012 (has links)
Muitos antibióticos de uso veterinário não são totalmente metabolizados no organismo animal, ocasionando a presença de resíduos destes compostos em várias matrizes ambientais, tais como estercos animais, solos e sedimentos fluviais. A ocorrência destes resíduos no ambiente pode favorecer a resistência de microrganismos aos agentes antibióticos, ocasionar problemas de ordem toxicológica em determinados organismos e, além disso, interferir nos ciclos biogeoquímicos mediados por microrganismos. Apesar do uso de antibióticos de uso veterinário ser elevado no Brasil, até o momento não existem dados quanto à ocorrência e comportamento ambiental dos principais compostos atualmente empregados no país. Neste sentido, este trabalho investigou a ocorrência em amostras ambientais (cama de frango e solo) de uma importante classe de antibióticos, as fluoroquinolonas, além de aspectos do comportamento de fluoroquinolonas e sulfonamidas através de ensaios de sorção. No exterior, estudou-se a dissipação e a sorção de fluoroquinolonas em solos neozelandeses. Para a quantificação de resíduos de fluoroquinolonas em amostras de cama de frango e solo, a metodologia analítica foi adaptada e validada. No geral, os resíduos de fluoroquinolonas ocorreram em concentrações equiparáveis (mg kg-1 para cama de frango e g kg-1 para solo) aos encontrados em outros países (China, Áustria e Turquia) e os seus coeficientes de sorção às partículas do solo foram sempre elevados (Kd = 544 a 1.277.874 L kg-1), maiores do que aqueles encontrados internacionalmente (Kd = 260 to 5.012 L kg-1), e bastante superiores aos encontrados na cama de frango (Kd 65 L kg-1), o que demonstra que o transporte destas moléculas ocorre somente em associação às partículas do solo, podendo atingir fontes de águas superficiais. Já os coeficientes de sorção das sulfonamidas foram relativamente baixos (Kd = 0,7 a 70,1 L kg-1), mostrando seu potencial de lixiviação no perfil dos solos. A textura e a capacidade de troca catiônica influenciaram significativamente o potencial de sorção das fluoroquinolonas e das sulfonamidas aos solos, evidenciando a importância dos processos de troca iônica na sorção desses antibióticos em solos tropicais. Nos solos neozelandeses, com maior capacidade tampão, o potencial de sorção das fluoroquinolonas também foi elevado, mas menor que em solos brasileiros, sendo que a adição de cama de frango diminuiu o seu potencial de sorção. A dissipação das fluoroquinolonas variou consideravelmente (DT50 = 16 a >70 dias), tendo sido mais rápida em sub-superfície apesar da sua menor atividade biológica. Antibióticos são usados rotineiramente na produção animal, representando uma fonte potencial de poluição ao meio ambiente que tem sido largamente ignorada, devendo ser melhor investigada no Brasil / Many antibiotics used for veterinary purposes use are not fully metabolized in the animal body, resulting in the presence of residues in a wide range of environmental matrices such as animal manures, soils and sediments. The occurrence of these residues in the environment can favour microorganisms resistance to antibiotic agents, cause toxicological problems to certain organisms and, besides, also interfere in the biogeochemical cycles mediated by microorganisms. Despite the high use of veterinary antibiotics in Brazil, so far there are no data regarding the occurrence and environmental behavior of the main compounds currently in use in the country. This work represented a first investigation on the occurrence of an important class of antibiotics, the fluoroquinolones, in environmental samples (poultry litter and soil), also investigating aspects of the environmental behavior of fluoroquinolones and sulfonamides in these matrices through sorption experiments. Overseas, dissipation and sorption behavior of fluoroquinolones were studied for New Zealand soils. For the quantification of fluoroquinolone residues in poultry litter and soil samples, an analytical methodology was adapted and validated. Overall, the results demonstrated the occurrence of fluoroquinolone residues in concentrations (mg kg-1 for poultry litter and g kg-1 for soil) comparable to those found elsewhere (China, Austria and Turkey), a high sorption potential of fluoroquinolones to soils (Kd from 544 to 1,277,874 L kg-1), higher than the reference values for soil (Kd = 260 to 5,012 L kg-1), and much higher than for poultry litter (Kd 65 L kg-1), showing that the transport of these molecules will only occur in association with the soil particles, possibly reaching superficial water sources. In the case of sulfonamides, sorption coefficients were relatively low (Kd = 0.7 to 70.1 L kg-1), showing their leaching potential in the soil profile. Texture and cation exchange capacity greatly affected the sorption of sulfonamides and fluoroquinolones to soils, emphasizing the importance of ion exchange processes on the sorption of antibiotics in tropical soils. In New Zealand soils, with a higher buffer capacity, sorption of fluoroquinolones was also high, but lower than to Brazilian soils, and the addition of poultry litter to soil reduced the sorption potential of these compounds. Fluoroquinolones dissipation varied considerably ((DT50 = 16 to >70 days), being faster in sub-surface samples despite its lower biological activity. Antibiotics are routinely used in animal production, representing a potential source of pollution to the environment that has been largely ignored and should be further investigated in Brazil
73

Ocorrência e comportamento ambiental de resíduos de antibióticos de uso veterinário / Occurrence and environmental behavior of residues of veterinary antibiotics

Rafael Marques Pereira Leal 28 May 2012 (has links)
Muitos antibióticos de uso veterinário não são totalmente metabolizados no organismo animal, ocasionando a presença de resíduos destes compostos em várias matrizes ambientais, tais como estercos animais, solos e sedimentos fluviais. A ocorrência destes resíduos no ambiente pode favorecer a resistência de microrganismos aos agentes antibióticos, ocasionar problemas de ordem toxicológica em determinados organismos e, além disso, interferir nos ciclos biogeoquímicos mediados por microrganismos. Apesar do uso de antibióticos de uso veterinário ser elevado no Brasil, até o momento não existem dados quanto à ocorrência e comportamento ambiental dos principais compostos atualmente empregados no país. Neste sentido, este trabalho investigou a ocorrência em amostras ambientais (cama de frango e solo) de uma importante classe de antibióticos, as fluoroquinolonas, além de aspectos do comportamento de fluoroquinolonas e sulfonamidas através de ensaios de sorção. No exterior, estudou-se a dissipação e a sorção de fluoroquinolonas em solos neozelandeses. Para a quantificação de resíduos de fluoroquinolonas em amostras de cama de frango e solo, a metodologia analítica foi adaptada e validada. No geral, os resíduos de fluoroquinolonas ocorreram em concentrações equiparáveis (mg kg-1 para cama de frango e g kg-1 para solo) aos encontrados em outros países (China, Áustria e Turquia) e os seus coeficientes de sorção às partículas do solo foram sempre elevados (Kd = 544 a 1.277.874 L kg-1), maiores do que aqueles encontrados internacionalmente (Kd = 260 to 5.012 L kg-1), e bastante superiores aos encontrados na cama de frango (Kd 65 L kg-1), o que demonstra que o transporte destas moléculas ocorre somente em associação às partículas do solo, podendo atingir fontes de águas superficiais. Já os coeficientes de sorção das sulfonamidas foram relativamente baixos (Kd = 0,7 a 70,1 L kg-1), mostrando seu potencial de lixiviação no perfil dos solos. A textura e a capacidade de troca catiônica influenciaram significativamente o potencial de sorção das fluoroquinolonas e das sulfonamidas aos solos, evidenciando a importância dos processos de troca iônica na sorção desses antibióticos em solos tropicais. Nos solos neozelandeses, com maior capacidade tampão, o potencial de sorção das fluoroquinolonas também foi elevado, mas menor que em solos brasileiros, sendo que a adição de cama de frango diminuiu o seu potencial de sorção. A dissipação das fluoroquinolonas variou consideravelmente (DT50 = 16 a >70 dias), tendo sido mais rápida em sub-superfície apesar da sua menor atividade biológica. Antibióticos são usados rotineiramente na produção animal, representando uma fonte potencial de poluição ao meio ambiente que tem sido largamente ignorada, devendo ser melhor investigada no Brasil / Many antibiotics used for veterinary purposes use are not fully metabolized in the animal body, resulting in the presence of residues in a wide range of environmental matrices such as animal manures, soils and sediments. The occurrence of these residues in the environment can favour microorganisms resistance to antibiotic agents, cause toxicological problems to certain organisms and, besides, also interfere in the biogeochemical cycles mediated by microorganisms. Despite the high use of veterinary antibiotics in Brazil, so far there are no data regarding the occurrence and environmental behavior of the main compounds currently in use in the country. This work represented a first investigation on the occurrence of an important class of antibiotics, the fluoroquinolones, in environmental samples (poultry litter and soil), also investigating aspects of the environmental behavior of fluoroquinolones and sulfonamides in these matrices through sorption experiments. Overseas, dissipation and sorption behavior of fluoroquinolones were studied for New Zealand soils. For the quantification of fluoroquinolone residues in poultry litter and soil samples, an analytical methodology was adapted and validated. Overall, the results demonstrated the occurrence of fluoroquinolone residues in concentrations (mg kg-1 for poultry litter and g kg-1 for soil) comparable to those found elsewhere (China, Austria and Turkey), a high sorption potential of fluoroquinolones to soils (Kd from 544 to 1,277,874 L kg-1), higher than the reference values for soil (Kd = 260 to 5,012 L kg-1), and much higher than for poultry litter (Kd 65 L kg-1), showing that the transport of these molecules will only occur in association with the soil particles, possibly reaching superficial water sources. In the case of sulfonamides, sorption coefficients were relatively low (Kd = 0.7 to 70.1 L kg-1), showing their leaching potential in the soil profile. Texture and cation exchange capacity greatly affected the sorption of sulfonamides and fluoroquinolones to soils, emphasizing the importance of ion exchange processes on the sorption of antibiotics in tropical soils. In New Zealand soils, with a higher buffer capacity, sorption of fluoroquinolones was also high, but lower than to Brazilian soils, and the addition of poultry litter to soil reduced the sorption potential of these compounds. Fluoroquinolones dissipation varied considerably ((DT50 = 16 to >70 days), being faster in sub-surface samples despite its lower biological activity. Antibiotics are routinely used in animal production, representing a potential source of pollution to the environment that has been largely ignored and should be further investigated in Brazil
74

Pesticidas Organoclorados (OCPs) em peixes comerciais capturados na Ba?a de Guanabara do Estado do Rio de Janeiro, Brasil / Organochlorine Pesticides (OCPs) in commercial fish from Guanabara Bay of Rio de Janeiro State, Brazil

FERREIRA, Verona Borges 21 February 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-18T13:59:23Z No. of bitstreams: 1 2017 - Verona Borges Ferreira.pdf: 1252759 bytes, checksum: 291a4f24b8d135e118f8e80afed31cfd (MD5) / Made available in DSpace on 2017-09-18T13:59:23Z (GMT). No. of bitstreams: 1 2017 - Verona Borges Ferreira.pdf: 1252759 bytes, checksum: 291a4f24b8d135e118f8e80afed31cfd (MD5) Previous issue date: 2017-02-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Brazil is among the world?s largest fish producers, and the state of Rio de Janeiro is one of the main responsible for this production. In addition, there is a substantial increase in fish consumption which is associated to its functional and nutritional properties, such as its lipid profile. Today the hydrographic bays of Rio de Janeiro suffer the impacts of excessive use of toxic substances, such as Organoclorine Pesticides (OCPs), which has a characteristic lipophilicity and tend to accumulate in adipose tissue of organisms. As a consequence, this may pose risk to consumers of fish from polluted environments. The human exposure to these pollutants is highly related to health problems, such as cancer, immunity diseases and endocrine disruptions. Thus, the present study aims at investigating the occurence of OCPs in sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri) and mullet (Mugil liza) from Guanabara Bay, located in the state of Rio de Janeiro, and also to estimate the OCPs intake through fish consumption. The analyses were carried out at the Laboratory of de Radioisotopes Eduardo Penna Franca at UFRJ. The analitical steps included sohxlet extration, purification and subsequent injection in a Gas Chromatography system coupled to a Mass Spectrometer on Negative Chemical Ionization mode (GC/MS/ENCI) to determine the OCPs concentrations. The estimative of the toxic compound intake was performed based on the obtained data for OCP in fish samples, the fish intake of the brazilian population, andavailable data of Acceptable Daily Intake (ADI) for each investigated pesticide. All samples had at least one OCP. Metoxichlor had the highest concentration for the three studied species. There was significant difference between the species concerning the concentration of o,p?-DDD and o,p?-DDT. These DDT metabolites were found at higher concentration in sardine samples in comparison to croaker and mullet ones. However, there was no significant difference between the species in relation to ?OCP. It was evidenced the greater proportion of DDE among the DDT metabolites which suggests the past use of this pesticide. Results for ?-HCH isomer indicate the contamination by the use of Lindane instead of the technical HCH mixture. There was no significant difference among the contamination of the three studied species in regard to sample's acquisition locations, showing that the locality does not influence the content of OCPs in fish, probably due the species behavior which travel big distances along the brazilian coast throughout their life cycle. No sample exceeded the maximum residue limit stipulated for OCPs at both national or international level. Based on the estimated intake data no species exceeded the toxicological safety parameter. Thus, the three studied fish species can be considered safe for human consumptiom in regard to OCPs exposure / O Brasil est? entre os maiores produtores mundiais de pescado, sendo o estado do Rio de Janeiro um dos principais respons?veis por essa produ??o. Al?m disso, existe um aumento substancial do consumo de peixes, que est? associado ? suas propriedades nutricionais e funcionais, como o seu excelente perfil lip?dico. As bacias hidrogr?ficas do Rio de Janeiro sofrem hoje os impactos do uso excessivo de subst?ncias t?xicas, como os Pesticidas Organoclorados (OCPs), que devido ? caracter?stica lipof?lica, tendem a se acumular no tecido adiposo de organismos aqu?ticos, o que pode representar um risco a sa?de de quem consome pescado oriundos de ambientes contaminados. Por sua vez, a exposi??o humana a estes poluentes est? altamente relacionada a problemas de sa?de, tais como o surgimento de c?ncer, problemas de imunidade e interfer?ncias end?crinas. Desta forma, o presente estudo tem por objetivo investigar a ocorr?ncia de OCPs em amostras de sardinha-verdadeira (Sardinella brasiliensis), corvina (Micropogonias furnieri) e tainha (Mugil liza) capturados na Ba?a de Guanabara, localizada no estado do Rio de Janeiro, assim como estimar a ingest?o de OCPs por meio do consumo de pescado. As an?lises foram realizadas no Laborat?rio de Radiois?topos Eduardo Penna Franca da UFRJ, atrav?s de sua extra??o, purifica??o e posterior inje??o em um sistema de Cromatografia Gasosa acoplada a um Espectr?metro de Massa por ioniza??o qu?mica negativa (CG/EM/NCI) para determinar as concentra??es de OCPs. Para estimar a ingest?o desses compostos t?xicos foram utilizados os dados de contamina??o das amostras, consumo do pescado pela popula??o brasileira, assim como os dados de Ingest?o Di?ria Aceit?vel (IDA) para cada contaminante. Todas as amostras investigadas estavam contaminadas com pelo menos um OCP, o Metoxicloro foi o pesticida encontrado em maior concentra??o nas tr?s esp?cies estudadas e houve diferen?a significativa entre as esp?cies em rela??o a concentra??o de o,p?-DDD e o,p?-DDT, estes metab?litos do DDT foram encontrados em maior concentra??o nas amostras de sardinha-verdadeira em rela??o as amostras de corvina e tainha, entretanto n?o houve diferen?a significativa entre as esp?cies em rela??o ao ?OCP. Ficou evidenciada a maior propor??o do DDE entre os metab?litos de DDT, n?o sugerindo o uso recente deste pesticida, e do is?mero ?-HCH entre os demais is?meros de HCH, evidenciando a contamina??o pelo uso de Lindano em rela??o ao HCH t?cnico. N?o houve diferen?a significativa entre a contamina??o das tr?s esp?cies com base nos diferentes pontos de coleta, demonstrando que a localidade de aquisi??o do pescado n?o influenciou no teor dessas subst?ncias, uma vez que estas esp?cies ao longo de seu ciclo de vida percorrem grandes dist?ncias pela costa brasileira. Nenhuma amostra excedeu os limites m?ximos de res?duo estipulados para esses contaminantes tanto a n?vel de regulamenta??o nacional quanto internacional. Com base nos dados de estimativa de ingest?o nenhuma esp?cie excedeu o par?metro toxicol?gico de seguran?a, sendo assim, as tr?s esp?cies estudadas s?o consideradas seguras para o consumo humano em rela??o a exposi??o a OCPs
75

Raspodela i profil zagađujućih jedinjenja u abiotskim i biotskim matriksima multivarijacionom analizom / Distribution and profile of pollutants in bioticand abiotic samples by multivariate statisticalapproach

Đurišić-Mladenović Nataša 16 November 2012 (has links)
<p>U okviru disertacije analizirano je prisustvo različitih postojanih zagađujućih<br />materija u abiotskim i biotskim uzorcima iz različitih regiona, uključujući i uzorke<br />zemlji&scaron;ta iz Novog Sada i okolnih naselja, i to zagađujuće materije organskog<br />(policiklične aromatične ugljovodonike, polihlorovane bifenile i organohlorne<br />pesticide) i neorganskog (te&scaron;ki elementi) porekla. Dobijeni rezultati uvr&scaron;teni su u<br />baze zajedno sa relevantnim podacima iz međunarodnih radova i na taj način<br />formirane su baze koje prevazilaze lokalne interese pojedinačnih istraživanja.<br />Primenom multivarijacionih metoda analize ovakvih baza utvrđen je stepen<br />zagađenosti ispitivanih uzoraka u odnosu na rezultate iz literature, a takođe je<br />razmatrana struktura formiranih multidimenzionalnih baza sa ciljem analize<br />raspodele postojanih zagađujućih jedinjenja u posmatranim matriksima i<br />identifikacije zajedničkih izvora zagađenja. Primenom različitih (matematičkih)<br />predtretmana podataka u bazama, a zatim njihovom analizom izabranim<br />multivarijacionim metodama, izvr&scaron;ena je procena uticaja predtretmana na<br />rezultate i mogućnosti njihove interpretacije, kao i ispitivanje zavisnosti između<br />posmatranih veličina i grupisanje uzoraka. Specifični ciljevi istraživanja su<br />omogućili da se:<br />- utvrde sličnosti i razlike pri kori&scaron;ćenju različitih načina izražavanja<br />analitičkih rezultata (apsolutne vrednosti koncentracije nasuprot relativnih<br />procentualnih udela, tzv. kompozicionih podataka) u okviru baza<br />podataka i pri izdvajanju informacija iz multidimenzionalnih baza<br />primenom multivarijacionih metoda,<br />- utvrdi uticaj različitih načina pripreme (obrade) podataka pre primene<br />multivarijacionih metoda radi dobijanja potpunijih informacija u cilju bolje<br />interpretacije podataka i smanjenja dimenzija baza podataka;<br />- ispitaju regionalne i vremenske razlike i/ili sličnosti između prisustva<br />posmatranih jedinjenja u abiotskim i biotskim matriksima radi uočavanja<br />dominantnih izvora zagađenja u određenim oblastima i vremenskim<br />periodima uz istovremenu karakterizaciju eksperimentalno ispitanih<br />uzoraka u odnosu na uzorke iz drugih regiona.<br />Postignuti rezultati predstavljaju jedinstvene rezultate primene multivarijacionih<br />metoda na bazama sastavljenim od podataka dobijenim u različitim<br />istraživanjima iz sveta o prisustvu postojanih zagađujućih materija u izabranim<br />abiotskim i biotskim uzorcima, doprinoseći tako analizi njihove op&scaron;te raspodele.</p> / <p>Presence of different pollutant classes of both organic (polycyclic aromatic<br />hydrocarbons, polychlorinated biphenyls and organochlorine pesticides) and<br />inorganic origin (heavy elements) were analysed in abiotic and biotic matrices<br />from various regions, including Novi Sad and its surrounding settlements.<br />Obtained results with available data published in the international articles were<br />included in the sets, forming the input matrices to be analysed by chemometric<br />techniques. Analysis of the created sets of data by multivariate approach was<br />performed due to determining pollution level of the investigated samples, as well<br />to elucidate the persistent pollutants distribution and profiles in the selected<br />matrices and to identify the common pollution sources.<br />Using different treatments of a set of input data, influence of these procedures to<br />results was assessed.<br />Specific aims of investigation were:<br />Determination of similarity and differences by using different ways of data<br />expression (apsolute values of concentrations as apposed to relative percent<br />fraction) in interpreration of multidimension data sets on the basis of multivariate<br />statistical approach<br />Determination of different processing of data before multivariate statistical<br />methods due to obtaining adequate information for interpretation of data and<br />reducing a set of original variables<br />Examination of regional and temporal differences and/or similarity among<br />presence of observed compounds in abiotic and biotic matrices due to<br />identification of dominant pollutant sources as well as comparative<br />characterisation of experimantally obtained data in relation to samples from<br />another regions worldwide.<br />Achieved results are unique examples of multivariate methods application on<br />large data sets with results on the occurance of pesistent organic compounds in<br />abiotic and biotic matrices obtained in different studies all over the world.</p>
76

Baseline Studies of Selected Polybrominated Diphenyl Ethers in the Air of the Nandamojo Watershed, Costa Rica

Geesey, Mary Sophia 24 March 2014 (has links)
Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in a number of common household and commercial products around the world. PBDEs enter the environment in a variety of ways, such as through emissions, leaching from end-of-life electronics in landfills, and incineration. While many countries have phased out the manufacturing of penta-, octa-, and deca-PBDEs or have banned the manufacture and use of these congeners altogether, these persistent organic pollutants (POPs) continue to be detected in humans and the environment. This study investigates spatial and temporal variations of selected PBDEs in the air of the Nandamojo watershed area in Costa Rica by comparing air concentrations of PBDEs in the dry winter vs. wet summer seasons and rural vs. urban areas and also investigates the impact of anthropogenic activities on air concentration of PBDEs. This study is significant to the field, because there are no baseline studies nor are there currently any monitoring programs to assess the environmental levels of PBDEs or other POPs for this region of the Guanacaste province. Baseline information is needed to track spatial and temporal trends as well as evaluate the effectiveness of control measures employed nationally and internationally. Samples obtained from passive air sampling devices were analyzed via GC/MS for a number of congeners. PBDE-47 and -99 were found to be the congeners present in greatest concentration in air samples from the Nandamojo watershed area. Air concentrations were estimated assuming an average sampler uptake rate of 3.5 m3/day and ranged as follows: ΣPBDE5 35.20-1549.25 pg/m3 over the entire study. The presence of PBDEs in remote and pristine environments indicates that PBDEs are now a global concern. This study suggests that the spatial and temporal distribution patterns observed are strongly related to anthropogenic activities and presence of a population similar to that observed in other studies. The presence of PBDEs has become a global issue and, as such, these results provide background information on air concentrations of PBDEs for use in a global-scale multimedia model. In order to monitor PBDEs globally, it is imperative to implement and/or expand surveillance programs internationally.
77

Persistent Organic Pollutants in Australian Sewage Sludge: Environmental Monitoring and Land Application Risk Assessment

Clarke, Bradley, Bradley.clarke@student.rmit.edu.au January 2008 (has links)
Presented is a study of persistent organic pollutants in Australian sewage sludge, focusing on environmental monitoring and a sewage sludge land application human health risk contaminated with these compounds. The chemicals of concern were: • Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and
78

Models of the Distribution of Persistent Organic Pollutants in the Marine Environment

Persson, N. Johan January 2003 (has links)
Persistent organic pollutants (POPs) is a group of chemicals that are toxic, undergo long-range transport and accumulate in biota. Due to their persistency the distribution and recirculation in the environment often continues for a long period of time. Thereby they appear virtually everywhere within the biosphere, and poses a toxic stress to living organisms. In this thesis, attempts are made to contribute to the understanding of factors that influence the distribution of POPs with focus on processes in the marine environment. The bioavailability and the spatial distribution are central topics for the environmental risk management of POPs. In order to study these topics, various field studies were undertaken. To determine the bioavailable fraction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated naphthalenes (PCNs), and polychlorinated biphenyls (PCBs) the aqueous dissolved phase were sampled and analysed. In the same samples, we also measured how much of these POPs were associated with suspended particles. Different models, which predicted the phase distribution of these POPs, were then evaluated. It was found that important water characteristics, which influenced the solid-water phase distribution of POPs, were particulate organic matter (POM), particulate soot (PSC), and dissolved organic matter (DOM). The bioavailable dissolved POP-phase in the water was lower when these sorbing phases were present. Furthermore, sediments were sampled and the spatial distribution of the POPs was examined. The results showed that the concentration of PCDD/Fs, and PCNs were better described using PSC- than using POM-content of the sediment. In parallel with these field studies, we synthesized knowledge of the processes affecting the distribution of POPs in a multimedia mass balance model. This model predicted concentrations of PCDD/Fs throughout our study area, the Grenlandsfjords in Norway, within factors of ten. This makes the model capable to validate the effect of suitable remedial actions in order to decrease the exposure of these POPs to biota in the Grenlandsfjords which was the aim of the project. Also, to evaluate the influence of eutrophication on the marine occurrence PCB data from the US Musselwatch and Benthic Surveillance Programs are examined in this thesis. The dry weight based concentrations of PCB in bivalves were found to correlate positively to the organic matter content of nearby sediments, and organic matter based concentrations of PCB in sediments were negatively correlated to the organic matter content of the sediment.
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Methodology for evaluation of hazards from solid waste and landfill-generated leachate

Svensson, Britt-Marie January 2008 (has links)
A methodology based on an analytical protocol for evaluation of hazards from landfill leachate and solid waste is described. A dynamic analytical protocol, the LAQUA protocol, including measurements of inorganic and water-quality parameters, polar and non-polar organic marker compounds, and toxicity, was constructed. An acute toxicity test, using the brackish water crustacean Artemia salina as test organism, was developed. The methodology was applied to authentic problems such as investigation of different treatment techniques for landfill leachate, evaluation of leaching tests and characterization of solid wastes, and an investigation of a filter material aimed for leachate treatment. Investigated treatment methods comprised in all cases pre-treatment by aeration combined with sedimentation, followed by one of: bioremediation, ozonation, chemical oxidation by Fenton’s reagent, or geo-bed filters. Evaluated filter materials were mixtures of natural or residual waste products. A combination of pre-treatment followed by a geo-bed filter containing a mixture of peat and carbon-containing ash gave an efficient simultaneous removal of metals and organic pollutants. The performance of two leaching tests for characterization of solid waste, the up-flow percolation test (SIS-CEN/TS 14405:2004) and the batch test (SS-EN 12457 -3), was investigated. Solid waste materials (sludge from street gutters and fragmented metallic waste) were characterized using leaching tests and the hazards of the materials were evaluated in the eluate, obtained at specific liquid-to-solid ratios (L/S). The L/S 2 and L/S 10 values were compared with limit values included in the waste acceptance criteria (WAC). The analyses were extended towards specific organic compounds, such as individual phenolic compounds and polychlorinated biphenyls (PCB). Organic compounds were found in eluates from both types of tests, showing the possibility to use these methods to evaluate the leaching of such compounds from waste materials. The use of authentic leachate as leachant, leads to increased concentrations of heavy metals in the eluate, compared to the prescribed use of demineralised water as leachant. Generally good agreement was found between the results of the two leaching methods. A strategy based on batch tests is described for investigation of a filter material for leachate treatment. Batch tests gave suitable information about the leaching from new and used material, and showed high removal efficiencies of metals and non-polar organic compounds. However, for investigation of removal of polar organic markers (e.g. phenolic compounds) a batch test is not sufficient and should be supplemented by a column test. / Avfall har alltid uppkommit i alla samhällen i alla tider. Det vanligaste sättet att hand om det har varit att samla avfallet i soptippar (deponier) på mark som ansetts obrukbar, t.ex. i sankmarker utanför bebyggelsen. I takt med ökad konsumtion och produktion har också mängderna avfall ökat. Anledningen till att avfall och avfallshantering kommit alltmer i fokus i miljödebatter under de senaste decennierna, är inte bara de stora mängderna avfall på de många och stora sopbergen runt om i världen. Deponierna släpper också ifrån sig miljöfarliga ämnen från de alltmer komplexa produkter som blivit lagda i deponin. Dessa kommer att fortsätta att läcka ut länge efter det att deponeringen på soptippen slutat, och skapa problem för människor och miljö i flera generationer. Som en konsekvens av internationella beslut bl.a. Agenda 21 (FNs miljökonferens i Rio) och EUs lagstiftning om avfallshantering som Sverige har tagit in i sin lagstiftning, kommer bl.a. antalet soptippar att minska. Efter den 31 december 2008 beräknas endast ett 90-tal deponier för kommunalt avfall att vara i drift i Sverige. Lagstiftningen beskriver en avfalls hierarki där deponering är den sämsta och absolut sista åtgärden som får göras bara när inget av de andra alternativen kan uppfyllas. Det ställs stora krav på de soptippar som är godkända enligt den nuvarande lagstiftningen. Olika typer av deponier ska finnas för olika slag av avfall. En deponi för farligt avfall har bättre skydd mot läckage både under och över tippen än en tipp för icke-farligt avfall. För att ha kontroll på vilket avfall som läggs på deponin och därmed kunna behandla det på korrekt sätt, måste avfallet beskrivas och klassas innan det skickas för deponering. Karakteriseringen görs bl.a. med hjälp av lakningstester. Syftet med denna avhandling har varit att utarbeta en metodik för at utvärdera miljöfarliga ämnen som kommer från avfall och lakvatten från soptippar. Den inledande forskningen utgjordes av ett projekt kallat Laqua, finansierat av EU-kommissionens program för samarbete inom Östersjöregionen, SweBaltcop. Projektets uppgift var att främja utveckling av ekologiskt och ekonomiskt hållbara reningsmetoder för lakvatten. Lakvattnet bildas främst av nederbörd som faller över deponin. Det vatten som kommer in i soptippen tar med sig många av de ämnen som finns i tippen när det rinner ut. Dessa ämnen kan komma från sådant som har deponerats eller bildas när avfallet bryts ner. Lakvattnet samlas upp och renas på något sätt innan det släpps ut till ett naturligt vattendrag. En vanlig metod att behandla lakvatten är att pumpa det till det kommunala avloppsreningsverket och rena det tillsammans med avloppsvatten. Men detta är ingen optimal lösning eftersom lakvatten innehåller andra föroreningar än avloppsvatten, t ex salter, tungmetaller och svårnedbrytbara organiska föreningar. Avloppsreningsverken är konstruerade för att rena avloppsvatten och lakvattnets föroreningar kan störa reningsprocessen. Framför allt kan de känsliga mikroorganismerna i det biologiska reningssteget påverkas negativt. Slammet som bildas vid reningsprocessen kommer att koncentrera många av de oönskade föroreningarna som härstammar från deponin. Slammet är egentligen ett utmärkt gödselmedel för jordbruket, men på grund av att slammet är förorenat av tungmetaller och svårnedbrytbara organiska ämnen kan inte slammet användas. Slammet blir då ett avfall som kommunen inte kan bli av med utan stora kostnader. Många kommuner har därför valt en separat rening av lakvattnet. Val av reningsteknik är beroende av flera faktorer, som volymerna lakvatten som uppkommer, innehållet av de olika miljöfarliga ämnena, vart det renande vattnet ska släppas ut och utrymme för att bygga en reningsanläggning. För att utvärdera olika tekniker för rening av lakvatten, byggdes en försöksanläggning på soptippen i Kristianstad. För att kunna utvärdera en reningsmetod måste bestämningar av koncentrationer av olika ämnen (analyser) göras. På grund av den ökande oron för organiska miljögifter som PCB och fenoler, skulle reningsteknikerna utvärderas med fokus sådana eller liknande ämnen. Analyser av organiska ämnen är komplicerade och tidskrävande, och det är inte möjligt att analysera alla ämnen. I många undersökningar används endast generella parametrar för att uppskatta innehållet av organiska ämnen, men dessa metoder ger ofta inte tillräcklig information om det egentliga innehållet i lakvattnet. Därför utarbetades ett utvärderings protokoll, LAQUA protokollet (artikel I) för bestämning av organiska miljögifter i olika förorenade vatten. Detta protokoll innehåller förutom analyser för organiska miljögifter som PCB och fenoler och en akut toxicitetstest, även standardiserade rutinanalyser av metaller och vattenkemiska parametrar. Eftersom separat analys av alla organiska ämnen inte nödvändig för att bedöma olika reningsmetoder för lakvatten, innehåller protokollet ett antal markörer för polära, respektive opolära organiska föreningar. Den biologiska giftighetstesten som utvecklades (artikel III) och ingår i protokollet är ett s.k. akut toxicitetstest, dvs. organismen påverkas direkt av höga halter av föroreningar. I testen används det lilla saltvattentåliga kräftdjuret Artemia salina, som säljs som föda åt akvariefiskar. En bestämd volym med ett antal Artemia larver läggs i små brunnar med olika koncentrationer av lakvatten under 24 timmar. Sedan jämförs vid vilken inblandning av lakvatten som hälften av kräftdjuren har fått rörelsestörningar. Resultaten på tester med obehandlat lakvatten, respektive behandlat med olika reningstekniker jämförs, och på det viset kan effektiviteten på reningsmetoder bedömas gentemot en vattenlevande organism. Utvärderingen av försöksanläggningen (artikel II) visade att vid förbehandlingen, bestående av luftning och sedimentering, togs mycket av föroreningarna bort, och det rekommenderas att ett sådan reningssteg alltid bör finnas vid en reningsanläggning för lakvatten. De kemiska behandlingsmetoderna med ozon och Fentons reagens (tvåvärt järn och väteperoxid) var effektiva på att ta bort de organiska miljögifterna, men även de mer kostnadseffektiva filterbäddarna visade sig fungera bra. Den goda erfarenheten från försöksanläggningen av filterbäddar ledde till att effektiviteten hos fler filter material undersöktes. I artikel VI beskrivs ett försök, gjord i laboratorium, där lakvatten från en soptipp som tar hand om industri avfall (metallavfall från bl.a. bilar och kylskåp) fick rinna genom kolonner med olika filtermaterial. Mixen av torv och aska med kolinnehåll visade sig vara bra på att ta bort både metaller och organiska ämnen från lakvattnet. Kunskapen från bl.a. dessa undersökningar har bidragit till att en fullskaleanläggning för lokal rening av lakvatten har kunnat byggas i anslutning till Stena metalls soptipp i Halmstad. Den andra delen i avhandlingsarbetet riktade in sig mot lakningstester. För att undersöka vilka ämnen som kan lakas ut från ett avfall rekommenderas två olika standardiserade lakningstests metoder. Vid den ena metoden pumpas en vätska genom en kolonn med en uppvägd mängd avfall tills ett visst vätske/fast fas förhållande (L/S halt) har uppnåtts. Vid den andra snabbare metoden, skakas en bestämd mängd avfall tillsammans med en bestämd volym vätska under 24 timmar. Den vätska som man får efter testerna kan jämföras med ett lakvatten och ska simulera den urlakning som avfallet ger ifrån sig under sin tid på deponin. Denna urlakningsvätska analyseras och de uppmätta halterna av olika ämnen jämförs med en gränsvärdes tabell och avfallet kan hänföras till en avfalls klass. De två lakningstesterna användes för att karakterisera olika avfallsslag, sönderdelat metall skrot (artikel IV) och slam från gatubrunnar (artikel V). För att få mer kunskap om metoderna och kunna vidareutveckla dem, utökades undersökningarna och analyserna. De urlakade vätskorna analyserades därför enligt Laqua protokollet, dvs med markörer för organiska miljögifter. Dessutom gjordes undersökningar där lakvatten användes som lakningsvätska istället för avjonat vatten som testmetoderna föreskriver. Dessa visade att den mer jonstarka vätskan (lakvattnet) ökade urlakningen av metaller från avfallet. En jämförelse av de två metoderna visade att den snabbare skaktesten oftast gav likvärdiga eller högre halter av de analyserade ämnena i urlakningsvätskan, och därmed kan den i många fall användas i första hand. För att bedöma ett filtermaterial ur ett livstidsperspektiv, utvecklades en strategi baserad på skaktester (artikel VII). Ett filtermaterial, en mix av torv och aska med kolinnehåll, undersökes före och efter att det använts i en filterbädd för rening av lakvatten. För att vara säker på att filtermaterialet i sig själv inte släppte ifrån sig några föroreningar gjordes en lakningstest. För att se hur effektivt materialet var på att ta bort metaller, PCB och fenolföreningar, gjordes skaktester med vätskor med kända halter av dessa föroreningar. När filtermaterialet är förbrukat och skall bytas ut anses det som ett avfall, och det karakteriserades med lakningstest för att hur det skulle tas om hand. Metodiken med skaktester ger bra information om utlakning från ett material, och skaktester är också bra instrument för att utvärdera ett filtermaterials effektivitet på att ta hand om metaller och opolära organiska ämnen som PCB. Men för att utvärdera effektiviteten av borttagandet av polära organiska ämnen (t ex. fenoler), är inte en korttids skak test något bra instrument. Reduceringen av dessa ämnen sker genom nedbrytning med hjälp av mikroorganismer, och för att undersöka detta behövs tester som varar en så lång tid att en mikrobiologisk miljö hinner etablera sig, t ex. kolonn tester. Utvärderingen av detta avhandlingsarbete visar på några ytterligare slutsatser och förslag till fortsatt arbete. Toxicitetstesten med Artemia bör kompletteras med tester på t ex. bakterier och växter, eftersom det inte räcker med en test på bara en organism för att bedöma giftigheten av en förorening ett naturligt ekosystem. Vidare behövs en biologisk test för att påvisa kroniska effekter, så som skador på fortplantning eller tumörsjukdomar. Dessa skador kan uppkomma genom att organismer påverkas under en lång tid av de låga, men därmed inte ofarliga halter av organiska miljögifter som ofta förekommer i lakvatten. Den presenterade metodiken kan användas för att utvärdera miljöfarliga ämnen från olika förorenade områden. Avhandlingen har visat att LAQUA protokollets sammansättning och dess analyser är ett bra instrument för att utvärdera reningstekniker för lakvatten och för att ge ytterligare information om organiska ämnen i fast avfall. Bedömning av luft kvalitet och karakterisering av dagvatten är andra exempel där metodiken kan användas. Avslutningsvis är det förstås lättare att utvärdera farligheten från avfall när det är mindre volymer avfall att utvärdera. Detta kan uppnås genom att konsumera mindre, återanvända produkter, återvinna material, utvinna energi ur avfallet och välja miljövänliga produkter när man köper nytt.
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Fate of polybrominated diphenyl ethers during wastewater treatment process producing reclaimed water

Siegel, Kristy 01 January 2013 (has links)
Polybrominated diphenyl ethers (PBDEs), flame retardants, have been applied to consumer goods, such as furniture, electrical devices, textiles, and appliances for decades. Due to their physico-chemical properties, PBDEs are semi-volatile and easily leach off the consumer good during aging, stress, or normal wear and tear of the good. Once airborne, they pose an environmental health threat because they can adsorb onto dust particles, soil, or other particulates that can be inhaled, ingested, or come into contact with the dermal layer. Additionally, PBDEs have a molecular structure similar to other persistent organic pollutants, such as polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and furans. They are a health threat due to their endocrine-disrupting nature by affecting thyroid functioning, fertility, and child development. The purpose of the study is to measure selected PBDEs in a wastewater treatment plant (WWTP) that produces reclaimed water, such that a mass balance can be completed, and to compare this mass balance with theoretically expected concentrations. The mass balance includes the collection of samples from wastewater, sewage sludge, and air at points within the WWTP. The PBDEs examined are BDE-28, 47, 99, 100, 153, 154, and 183. The second part of the study will compare effluent concentrations to reclaimed water concentrations in order to examine the potential exposure (if any) of using reclaimed water. Influent concentration of mean (sum7)PBDE was found to be 49,117 pg/L and effluent concentration was 4,603 pg/L, illustrating a 91% removal rate of PBDEs during the wastewater treatment plant. Sludge samples contained the highest total concentrations of PBDEs with mean (sum7)PBDE ranging from 14.0 to 41.3 ug/kg dry weight. Air samples were highest at the post-aeration (248 pg/m3 mean (sum7)PBDE) step due to the use of highly oxygenated air assisting in the release and volatilization of the PBDEs. Sludge was found to carry the largest mass loading at 14.2 lb/day (sum7)PBDE. Of the total mass loading of PBDEs from the WWTP, sludge is responsible for 86.7%, followed by reclaimed water and effluent (11.7% and 1.6%, respectively). The mass loading from air was negligible with less than 0.01% contribution to the total mass loading. Whereas reclaimed water overall had higher PBDE congener mean concentrations than the effluent, the independent samples t-test found no statistically significant differences between the two groups. The results of this study can be used to improve the wastewater treatment process to reduce the impact of PBDEs being released into the environment by WWTPs, and to educate the public on utilizing reclaimed water in a safe and healthy manner.

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