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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.
21

Arsenic Release from Dechlorination Remediation Processes of Biostimulation and Bioaugmentation

Smith, Suzy 01 May 2015 (has links)
Arsenic (As), a known carcinogen, is a groundwater contaminant in many parts of the world. Arsenic contamination is enhanced through carbon addition, such as biostimulation, a remediation process, which has been used to remove trichloroethylene (TCE) from sediment and groundwater. Two studies were designed to evaluate the effect of different carbon sources on the removal of TCE through dechlorination and on As solubilization and mobilization in response to carbon addition. The first set of columns (15.2 cm diameter, 183 cm long) used whey, Newman Zone® standard surfactant emulsified oil, Newman Zone® nonionic surfactant emulsified oil, and no carbon controls as carbon and energy sources and were fed for 7.5 years. The second set (7.62 cm diameter and length) used whey, lactate, and no carbon control as carbon sources with columns being dismantled and analyzed over a 5-month time period. These studies showed that reducing conditions, caused by the carbon sources, was the driving force for As mobilization as As(V) was reduced to the more mobile As(III). Total As mass in the sediment was lost with all carbon treatments within the first study with whey having a greater loss; however, within the second study, both whey and lactate treatments had the same extent of As mass loss over time. The results also indicated that some As could be attenuating with carbonates or other highly soluble minerals.
22

Treatment of Petroleum Hydrocarbons in Oil-Based Drill Cutting Mud Using BiOWiSH Bioaugmentation Products

Zepeda, Diego Jose Cardenas 01 June 2015 (has links) (PDF)
The efficacy of BiOWiSHTM-Thai Aqua, a commercially discontinued microbial product, in remediating oil based drill-cutting mud (DCM) was researched in this study. Experimentation was performed directly on DCM and on sand contaminated with oil extracted from DCM. A gas chromatograph-mass spectrometrer and a respirometer were used for analysis of total petroleum hydrocarbons (TPH) and CO2 production respectively. Five experiments were analyzed by TPH extraction and analysis; four experiments were analyzed by respirometric analysis. The specific microcosm conditions tested in the experiments were control, nutrient-only control, and bioaugmentation product. This study concluded that there might be potential for bioaugmentation of TPH using BiOWiSHTM-Thai Aqua. However, a more extensive study including multiple replicates of samples over a longer sampling time period is required to make a conclusion. TPH analysis from the Sand Microcosm Experiment suggested that in seven days, the addition of BiOWiSHTM-Thai Aqua improved TPH removal relative to the control by 89% while the nutrient-only control improved by 58%. Respirometric analysis suggested CO2 respiration of glucose overshadowed CO2 respiration from biodegradation. Thus, major conclusions could not be made from the respirometric analysis.
23

TREATMENT OF WASTEWATER CONTAINING PHENOL AND HEAVY METALS USING NATURAL ZEOLITE AND BIOAUGMENTATION

Jameson, Patrick Brian January 2007 (has links)
No description available.
24

Enhancement of hydrolysis from co-fermentation of food waste and primary sludge / Förstärkning av hydrolys genom samfermentering av matavfall och primärt slam

Hagelin, Johnny January 2021 (has links)
Research about resource recovery from complex waste streams is getting an increased scientific attention since valuable resources can be produced by sustainable biological means. In anaerobic degradation processes, resources such as volatile fatty acids (VFAs) and biogas are highly coveted. One of the key parameters affecting the yield of resources is the hydrolytic efficiency in the waste stream by hydrolytic bacteria. The aim of this study was to examine how bioaugmentation can be implemented as a strategy to enhance hydrolysis in complex waste streams. In pursuit of this aim, three selected species of hydrolytic bacteria, Bacteroides thetaiotaomicron, Bacteroides amylophilus and Bacteroides ruminicola were inoculated both in pure culture combinations and bioaugmented with granular sludge as mixed culture in reactors. The studied waste stream was food waste mixed with primary sludge collected from Henriksdals wastewater treatment plant at Stockholm, Sweden.  The highest hydrolytic efficiency (90%) was reached by the pure culture fermented reactor inoculated with Bacteroides thetaiotaomicron and Bacteroides ruminicola. This efficiency was measured at day 10 after reactor set-up. Among the bioaugmented reactors, highest hydrolytic activity (66%) was achieved by the reactor inoculated with Bacteroides thetaiotaomicron and it was measured at day 10. The increase in hydrolytic efficiency for bioaugmented reactors was slower compared to pure culture fermented reactors and the most probable reason to that is due to competition amongst introduced species and pre-existing mixed culture in granular seed sludge. / Mer uppmärksamhet riktas till forskning kring resursåtervinning från komplexa avfallsströmmar eftersom värdefulla resurser kan produceras genom mer hållbara biologiska tillvägagångssätt. I anaeroba nedbrytningsprocesser är produkter såsom flyktiga fettsyror (VFAs) och biogas mycket eftertraktade. En av huvudparametrarna som påverkar utbytet av återvunna resurser är den hydrolytiska effektiviteten i avfallsströmmen av hydrolytiska bakterier. Syftet med studien var att undersöka hur bioaugmentering kan implementeras som strategi för att förstärka hydrolys i komplexa avfallsströmmar. Därav utfördes fermentering med tre valda hydrolytiska bakterier, Bacteroides thetaiotaomicron, Bacteroides amylophilus och Bacteroides ruminicola både i renkultur och bioaugmenterat med granulärt slam som mixad kultur i reaktorer. Avfallsströmmen som studerades var matavfall mixat med primärt slam hämtat från Henriksdals vattenreningsverk i Stockholm, Sverige.  Högsta hydrolytiska effektivitet (90%) uppnåddes för reaktorn inokulerat med Bacteroides thetaiotaomicron och Bacteroides ruminicola i renkultur. Denna effektivitet uppmättes dag 10 efter reaktorerna sattes upp. För de bioaugmenterade reaktorerna så uppnåddes högsta hydrolytiska effektivitet (66%) dag 10 av reaktorn inokulerat med Bacteroides thetaiotaomicron. Ökningen i hydrolytisk effektivitet var långsammare för de bioaugmenterade reaktorerna jämfört med reaktorerna med renkultur. Den mest sannolika förklaringen till det är tävling om näringsämnen och vitaminer mellan introducerade bakterier och de bakterier som redan existerar i det granulära slammet.
25

Biodegradation and Dewatering of an Industrial Waste Oil

McInnis, Jeffrey A. 01 May 2003 (has links)
Waste oil generated from industrial operations at a diesel locomotive maintenance facility was investigated to establish its treatability and potential volume reduction. The waste oil and water mixture separated into four distinct layers; free oil, emulsified oil, weathered oil, and wastewater. The research was conducted in a series of three batch experiments and focused on the emulsified and weathered oils. The waste oil was aerobically treated in nutrient amended, 55 gallon (208 L) drums for 38 to 42 days in 10 and 20 % mixtures with sufficient air for mixing and oxygen. Biodegradation, and the role of a synthetic surfactant in promoting biodegradation, was measured using chemical oxygen demand (COD), fluorescein diacetate (FDA), and gas chromatography (GC) analyses with extractable material. Dewatering of biodegraded oil was measured using capillary suction test (CST), time to filter (TTF), and percent cake solids. Batch 1 examined the role of bioaugmentation by comparing a 10% waste oil mixture that was augmented with a mixture of hydrocarbon degraders to a 10 % mixture of waste oil with no bioaugmentation. Final COD reductions were 59 (± 9) and 38 (±3) % for the bioaugmented and non-bioaugmented reactors, respectively. Chromatographs showed significant reduction in the abundance of peaks by the end of the experiment for both reactors. Overall results suggested that there was no significant difference in biodegradation capabilities between the amended and native microorganisms. Batch 2 was conducted to determine if a synthetic surfactant (Tween-80) could enhance biodegradation of a 10 % waste oil mixture. The surfactant-amended reactor showed COD reduction 3 days before the non-surfactant-amended reactor. Chromatographs showed similar results for both reactors with the non-surfactant-amended reactor showing slightly better degradation by the end of the experiment. The total COD reduction by the end of the experiment was the same in both (R1: 85 ± 20%, R2: 84 ± 16 %), suggesting that exogenous surfactant addition did not have a long-term impact in the biodegradation of the waste oil. Batch 3 examined the effect of different oil phases and concentrations on biodegradation and the dewatering characteristics of post-biodegraded waste oil. The 20 % weathered and emulsified waste oil mixture showed a clear delay in COD reduction (no notable reduction until day 24) compared to the 10 % weathered waste oil mixture. The final COD reductions were the same (R1: 48 ± 13%, R2: 49, ± 23 %). Chromatographs showed similar results for both reactors and indicated that degradation of the waste oil occurred in both reactors. The data suggest that the 20 % waste oil mixture can be degraded to the same extent as the 10 % mixture in 38 days. Dewatering characteristics, as measured by CST, were poor for the 20 % post-biodegraded combined waste oil mixture without conditioning. Conditioning with alum or ferric chloride substantially improved dewatering of the waste oil for the 20 % mixture but was of limited benefit for the 10 % mixture. Percent cake solids for conditioned 10 % post-biodegraded waste oil mixture was 44 (± 0.3) to 50 (± 1.7) % and 34 (± 0.3) to 50 (± 1.8) % for the 20 % mixture. The cake solids for the unconditioned 10 % mixture was 50 to 65 % and 54 to 68 % for the 20 % mixture. The higher percent cake solids for the unconditioned 20 % mixture was countered by the very high TTF (up to 30 min. to filter 50 mL) and the inability to dewater the sludge during the last five sampling events. Conditioning appeared to have a limited effect on the dewatering properties of the 10 % mixture. / Master of Science
26

Impact des exsudats racinaires de Miscanthus x giganteus sur les microorganismes impliqués dans la bioremédiation d’un sol contaminé au benzo(a)anthracène / Impact of Miscanthus x giganteus root exudates on microorganisms invoved in the bioremediation of a benzo(a)anthracene contaminated soil

Mazziotti, Mélanie 03 May 2017 (has links)
Les activités industrielles sont à l’origine d’un grand nombre de sites et sols pollués en France. Parmi les polluants retrouvés, les hydrocarbures aromatiques polycycliques (HAP), notamment ceux de haut poids moléculaire, posent un réel problème environnemental et de santé publique en raison de leur toxicité et de leur persistance dans les sols. Les techniques biologiques de remédiation qui stimulent la dégradation microbienne des HAP en utilisant des plantes (phyto/rhizoremédiation), des nutriments (biostimulation), ou encore des microorganismes (bioaugmentation), apparaissent comme des stratégies intéressantes car elles sont plus respectueuses de l’environnement et moins onéreuses que les méthodes physico-chimiques. Dans ce contexte, la capacité de la plante Miscanthus x giganteus (MxG) à améliorer la dissipation du benzo(a)anthracène (BaA), un HAP de haut poids moléculaire peu étudié en remédiation, a été évaluée par une approche pluridisciplinaire en réalisant deux types d’expérimentations à partir d’un sol artificiellement contaminé. La première a consisté à analyser l’influence rhizosphérique de la plante (phyto/rhizoremédiation) au cours d’une période de 12 mois. Les résultats ont montré que la présence de MxG conduisait en fin d’exposition à une réduction 3 fois plus importante de la teneur en BaA dans le sol grâce à une augmentation de la biodisponibilité du contaminant et à un effet positif sur les communautés microbiennes via une modification de leur diversité et une augmentation de leur densité de gènes ARNr 16S et PAH-RHDα GP. Afin d’améliorer la compréhension de ce phénomène, une deuxième expérimentation a été mise en place sur une durée de 105 jours dans le but d’étudier spécifiquement l’influence de certaines molécules exsudées au niveau du système racinaire de la plante (biostimulation) et de microorganismes spécifiques, associés à sa rhizosphère, ayant la capacité de dégrader le BaA (bioaugmentation). Ces essais ont témoigné de la complexité des mécanismes rhizosphériques et de la nécessité d’approfondir ce type d’analyses afin d’améliorer la compréhension des processus de biodégradation dans la rhizosphère de la plante. L’ensemble de ces résultats a alors montré que MxG était une candidate idéale pour la phyto/rhizoremédiation de sols contaminés par des HAP de haut poids moléculaires mais que des études supplémentaires étaient encore nécessaires pour comprendre les processus intervenant dans sa rhizosphère / Industrial activities result of a large number of contaminated sites and soils in France. Among the pollutants found, polycyclic aromatic hydrocarbons (PAHs), and especially those of high molecular weight, are a real environmental and public health problem because of their toxicity and persistence in soils. Biological remediation techniques which stimulate microbial degradation of PAHs using plants (phyto/rhizoremediation), nutrients (biostimulation), or microorganisms (bioaugmentation), appear as interesting strategies because they are more environmental friendly and less expensive than physico-chemical methods. In this context, the ability of the plant Miscanthus x giganteus (MxG) to improve benzo(a)anthracene (BaA) dissipation, a high molecular weight PAH few studied in remediation, was assessed with a multidisciplinary approach through two types of experimentations using an artificially contaminated soil. The first one was to analyze the rhizospheric influence of the plant (phyto/rhizoremediation) over a period of 12 months. Results showed that the presence of MxG led to a 3-fold reduction in BaA concentration in soil at the end of exposure thanks to an increase in pollutant bioavailability, and a positive effect on microbial communities due to a modification of their diversity and an increase in their 16S rRNA and PAH-RHDα GP genes density. In order to improve the understanding of this phenomenon, a second experiment was carried out for 105 days to study specifically the influence of certain molecules exuded in the plant’s root system (biostimulation), and specific microorganisms associated with its rhizosphere having the capacity to degrade BaA (bioaugmentation). These tests demonstrated the complexity of rhizospheric mechanisms, and the necessity to explore this type of analysis to improve the understanding of biodegradation processes in plant rhizosphere. All these results showed that MxG was an ideal candidate for phyto/rhizoremediation of soils contaminated with high molecular weight PAH, but that further studies were still needed to understand processes involved in its rhizosphere
27

Using bioaugmentation to enhance the denitrification process in a treatment plant for landfill leachate

Skirfors, Oscar January 2020 (has links)
It has been illegal to deposit household waste in Swedish landfills since 2005. The large amount of waste deposited prior to this does however continue to pose an environmental concern, mainly in the form of leachate water. This study focused on enhancing the denitrification process in a leachate water treatment plant through bioaugmentation. The two strains Brachymonas denitrificans and Comamonas denitrificans as well a commercial seed mix from ClearBlu Environmental® (CBE-mix) containing amongst others, Pseudomonas putida AD 21 and Pseudomonas fluorescens, were investigated as candidates. Nitrite, nitrate, and ammonium concentrations were measured in laboratory-, and pilot-scale studies to follow the processes of nitrification and denitrification. The pilot study was conducted for 10 days in the middle of May 2020 with leachate from the treatment plant in an aerated and nonaerated setup in open field conditions. C. denitrificans and B. denitrificans were both shown to be able to adapt to growth in landfill leachate. The addition of these strains led to a higher rate of nitrate reduction compared to the control during the first days of the pilot experiment but showed no difference in the total amount of nitrate reduced. The combined nitrogen concentration of ammonium, nitrate, and nitrite was 6.7% lower than the control when using a culture augmented with the CBE-mix in the aerated setup. This could indicate aerated denitrification. The amount of nitrate reduced during the pilot experiment was increased with 32% when augmenting the community with the CBE-mix in a nonaerated setup. An explanation could be that certain strains in the mix were able to utilize hard to degrade organic carbon present in the leachate or that the mix had a higher ratio of reduced nitrate to consumed organic carbon than the indigenous community. / Det har varit olagligt att deponera hushållsavfall i Sverige sedan 2005, den stora mängd avfall som deponerats innan dess fortsätter dock att utgöra ett miljöproblem, främst genom genereringen av lakvatten. Den här studien fokuserade på möjligheten att förbättra denitrifikationen i ett reningsverk för lakvatten genom bioaugmentation. Två stammar tillhörande Brachymonas denitrificans, och Comamonas denitrificans, samt en kommersiell bakterieblandning från ClearBlu Environmental® innehållande bland andra Pseudomonas putida AD 21 och Psedomonas flourescens, undersöktes som möjliga kandidater. Ammonium-, nitrat- och nitritkoncentrationer mättes i odlingsstudier i labbskala och i en pilotstudie för att undersöka nitrifikation och denitrification. Pilotstudien utfördes i en luftad och en o luftad konfiguration utomhus i mitten av maj 2020, med lakvatten från reningsverket under en 10 dagars period. C. denitrificans och B. denitrificans klarade båda av att anpassa sig till tillväxt i lakvatten. Tillsats av dessa arter ledde till en ökning i nitratreduktionshastighet i början av pilotexperimentet men gav ingen total minskning av nitratmängden. Den sammanlagda slutkoncentrationen av ammonium-, nitrat- och nitritkväve var 6,7% lägre än i kontrollen när en kultur argumenterad med den kommersiella bakteriemixen användes i den luftade konfigurationen. Mängden reducerat nitrat ökade med 32% när en kultur augmenterad med den kommersiella mixen användes i den oluftade konfigurationen. En möjlig förklaring är att vissa stammar i mixen klarade av att tillgodogöra sig svårnedbrytbara kolföreningar i lakvattnet eller att ration mellan reducerat nitrat mot konsumerat organiskt kol var högre än i det ursprungliga microbsamhället.
28

Développement d'un procédé de traitement de matrices d'origine viticole polluées par des herbicides par couplage bioaugmentation/phytoremédiation : sélection d'un triplet bactéries - sorbant - plante testé en microcosme

Bois, Paul 17 May 2010 (has links) (PDF)
Cette étude vise à développer un système de dépollution d'eau et de sédiments viticoles. Le glyphosate, diuron et 3,4-dichloroaniline (3,4-DCA) sont considérés, en tenant compte de la charge en cuivre. L'augmentation du temps de séjour des polluants dans le système et le choix de la bioaugmentation couplée à la phytoremédiation est la stratégie retenue. Chaque composante d'un triplet " sorbant-inoculum bactérien-plante " a été sélectionnée en laboratoire et le triplet mis en oeuvre en microcosmes en conditions partiellement contrôlées.La sélection de matériaux sorbants dans différentes matrices liquides en présence des polluants seuls ou en mélange montre que les capacités de sorption des différents matériaux testés varient selon le polluant, sa formulation (seul ou en mélange) et la matrice liquide. Le sédiment se révèle être le meilleur sorbant pour le glyphosate ; le sable pour le diuron et le 3,4-DCA.Les performances de dissipation des colonies tolérantes isolées varient fortement selon le polluant. Le consortium sélectionné pour le procédé dissipe le glyphosate, le diuron et le 3,4-DCA en milieu liquide et complexe par ailleurs le cuivre.L'expérience en microcosmes montre que le temps de rétention hydraulique influe sur l'efficacité du système et que les matériaux sorbants sont efficaces. De plus les performances de dissipation atteintes sont bonnes. L'effet de la bioaugmentation sur les performances de dissipation n'est pas significatif pour le glyphosate et le 3,4-DCA, mais améliore en moyenne la dissipation du diuron. Un temps d'action prolongé dans la matrice solide s'avère nécessaire pour obtenir une bonne efficacité du procédé.
29

Bioestímulo e bioaumento na remediação de solo contaminado com óleo lubrificante usado escala piloto / Biostimulation and bioaugmentation in the remediation of soil contaminated by oil lubrificant pilot reactors

Graciane Silva 17 November 2010 (has links)
O óleo lubrificante mineral é amplamente utilizado no cenário mundial no funcionamento de máquinas e motores. No entanto, o ciclo de vida deste petro-derivado resulta na geração de um resíduo (óleo lubrificante usado), o qual é nocivo ao meio ambiente quando não descartado adequadamente ou reciclado. No Brasil, apesar das normas que tratam especificamente do armazenamento, recolhimento e destino de óleo lubrificante usado, grande parte do mesmo ainda é despejado diretamente no meio ambiente, sem qualquer tratamento, sendo de grande importância estudos que visem o entendimento dos processos e o desenvolvimento de tecnologias de remediação de áreas contaminadas por esse resíduo. O objetivo geral do presente trabalho foi conduzir estudos de tratabilidade de solo arenoso contaminado experimentalmente com 5% (m m-1 seco) de óleo lubrificante usado, através de duas diferentes estratégias de biorremediação: bioestímulo e bioaumento. Foram conduzidos dois experimentos. No primeiro, foi avaliada a atividade microbiana aeróbia na biodegradação do OLU através do método respirométrico de Bartha. No segundo, foram montados três biorreatores de fase sólida simulando biopilhas estáticas com aeração forçada, cada um contendo 125 kg de solo e 5% (m m-1 seco) de óleo lubrificante automotivo usado, os quais receberam como tratamento: bioestímulo por ajuste de pH e umidade (BIOSca); bioestímulo por ajuste de pH e umidade associado ao bioaumento com a adição de composto maduro (BIOA1ca) ; e bioestímulo por ajuste de pH e umidade associado ao bioaumento com a adição de composto jovem (BIOA2ca). Foram também montados três biorreatores de bancada simulando biopilhas estáticas sem aeração forçada, cada um contendo 3 kg de solo e 5% (m m-1) do mesmo contaminante, sendo que o primeiro continha solo sem contaminação - CONTsa, o segundo, solo contaminado com ajuste de pH BIOSsa e o terceiro, solo contaminado com adição de 0,3% de azida sódica - ABIOsa. Os tratamentos foram avaliados pela remoção de hidrocarbonetos totais de petróleo (HTPs) e após 120 dias de experimento obteve-se remoções de HTPs de 84,75%, 99,99% e 99,99%, com BIOS, BIOA1 e BIOA2, respectivamente, demonstrando que a estratégia de bioestímulo associada ao bioaumento foram promissoras na remediação do solo contaminado pelo óleo lubrificante usado. Os tratamentos que receberam composto (BIOA1 e BIOA2) não apresentaram diferenças quanto à remoção de HTPs, evidenciando que a fase de maturação dos compostos não apresentou influência na eficiência do processo. No entanto, verificou-se uma eficiência nos tratamentos que receberam composto quando comparado ao tratamento sem adição de composto / Lubricating oil is worldwide in machinery and motors. The life-cycle of this petroleum-based product generates a waste, the spent lubricating oil SLO, which is hazardous to the environment when inappropriately disposed. In Brazil, regardless the norms that establish rules for storage, collection, recycling and final disposal of spent-lubricating oil, a large part of it ends up in different environment compartments, causing among others, soil contamination. Therefore, it is important to carry out studies focusing on processes and technology development for remediation of sites contaminated by SLO. The objective of this work was to carry out two experiments of treatability studies for sandy soil contaminated experimentally with 5% (weight/dry weight) of SLO, through two different bioremediation strategies: biostimulation and bioaugmentation. During the first experiment, the aerobic microbial activity in SLO-contaminated soil was assessed through Barthas respirometry (CO2 productino). During the second experiment, three reactors simulating static biopiles with forced (up-flow) aeration received 125 kg of soil contaminated with 5% (w/dw) SLO, which received the following treatments: pH and moisture adjustment-BIOSca; pH and moisture adjustment associated to bioaugmentation through addition of mature compost from urban solid waste-BIOA1ca and pH and moisture adjustment associated to bioaugmentation with non-mature compost-BIOA2ca. Another group of three bench reactors with no forced aeration, each one containing 3 kg of soil also contaminated with 5% (w/dw) of SLO were filled as following: the first received non-contaminated soil-CONTsa; the second received contaminated soil with pH adjustment-BIOSsa; the third one received contaminated soil with addition of 0.3% (w/dry w) of sodium azide-ABIOsa. The treatments were compared based on removal of total petroleum hydrocarbons (TPHs) and its fractions. After 120 days, the TPH removal was about 75%, 99.99% and 99.99% in BIOS, BIOA1 and BIOA2 respectively, suggesting that optimization of conditions associated to bioaugmentation were the most promising strategy to treat SLO contaminated soils. The fact that after 120 days BIOA1 e BIOA2 did not present differences regarding TPH removal shows that giving time enough, the degree of the compost maturation does not influence the TPH removal. However, treatments that received compost were more efficient than biostimulation alone
30

Avaliação do pré-tratamento do efluente de indústria química com adição de linhagens microbianas especializadas na degradação de compostos tóxicos / Evaluation of the industrial wastewater pretreatment adding microbial strains specialized in toxic compounds degradation

Machado, Flavio Silva 28 July 2009 (has links)
As indústrias químicas são consideradas como o segmento industrial que gera os efluentes mais perigosos ao meio ambiente. Em virtude das concentrações expressivas de poluentes, tanto orgânicos quanto inorgânicos, os efluentes dessas indústrias podem interferir na atividade da biomassa de estações de tratamento de efluentes (E.T.E.), diminuindo sua eficiência e gerando efluentes tratados, porém em desacordo com a legislação pertinente. Para prevenir tais efeitos, o recebimento de efluentes industriais em E.T.E.s pode ser precedido por pré-tratamento, dentre os quais, o biológico, otimizado pela adição de microrganismos com capacidade de degradar poluentes. Foram isolados microrganismos com capacidade de degradar os compostos identificados como responsáveis pela toxicidade do efluente final da E.T.E.: benzeno, clorofórmio, 1,2-dicloroetano, pentaclorofenol, tricloroeteno, tolueno e p-xileno. Foram realizados testes de bioaumentação para pré tratar o efluente industrial, que foram avaliados através de ensaios físico-químicos e de toxicidade aguda para Vibrio fischeri e Daphnia similis. Os resultados obtidos demonstraram que o pré tratamento reduziu a toxicidade do efluente final da estação de tratamento. / Chemical industries are considered the industrial sector that generates the most dangerous effluents to the environment. Due to the high pollutant concentration, either organics or inorganics, the chemical industries effluents may interferer in the biomass activity in wastewater treatment plants (WWTP), what may reduce its efficiency and generate treated effluents in disagreement to the concerned law. In order to prevent such effects, the industrial effluents disposal in WWTPs can be preceded by biological pretreatment, which can be optimized by adding microorganisms capable of pollutants degradation. Microorganism strains that are able to degrade the compounds identified as the responsible for toxicity levels in the WWTP final effluent: benzene, chloroform, 1,2-dichloroethane, pentachlorophenol, trichloroethene, tolune and p-xylene were isolated. Bioaugmentation tests aiming the chemical effluent pretreatment were performed and they were evaluated through physical-chemical analysis and acute toxicity tests for Vibrio fischeri and Daphnia similis. The results showed that the industrial effluent pretreatment reduced the toxicity levels in the WWTP final effluent.

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