Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016. / The worldwide high demand for drinking water has led to the development of numerous advanced wastewater treatment processes. Photocatalysis has recently become an alternative and attractive technique for green energy production and environmental remediation. It is also a wastewater treatment technique which is considered reliable and is expected to provide a sustainable solution to the scarcity of clean water. In particular, heterogeneous photocatalysts based on TiO2 nanoparticles and sunlight have been proposed as a powerful technique for degradation and mineralisation of persistent organic pollutants (POP`s). Although this method seems promising, some critical challenges are still to be addressed: namely, low photoefficiencies, faster electron and hole (𝑒−⁄ℎ+) pair recombination, utilisation of UV light and catalyst removal after treatment of pollutants.

Thesis (DTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / The high rate of industrialisation in most developing countries has brought about challenges of wastewater management especially in the mineral processing industry. Cyanide has been used in base metal extraction processes due to its lixiviant properties thus, its presence in wastewater generated is inevitable. Furthermore, partial and/or the use of unsuitable treatment methods for such wastewater is a potential hazard to both human and the environment. There are several reports on biotechnological treatments of cyanide containing wastewater but few mineral processing industries have adopted this approach. Hence, the thermodynamic study of biodegradation of cyanide containing wastewater was undertaken. The primary aim of this study was to explore the application of bioenergetic models and biological stoichiometry to determine the functionality and thermodynamic requirements for cyanide degrading isolate (Fusarium oxysporum EKT01/02), grown exclusively on Beta vulgaris, for a system designed for the bioremediation of cyanidation wastewater. Chapter 2 reviews some of the applicable thermodynamic parameters such as enthalpy, entropy, heat of combustion, heat capacity, Gibbs energy, including stoichiometry models in relation to their applicability for microbial proliferation in cyanidation wastewater. The chapter places emphasis on the application of agro-industrial waste as a suitable replacement for refined carbon sources for microbial proliferation in bioremediation systems because such systems are environmentally benign. The choice of using agro-industrial waste is due to organic waste properties, i.e. agro-industrial waste is rich in nutrients and is generated in large quantities. Chapter 3 presents the materials and various standardised methods used to address the research gaps identified in chapter 2. For an organism to degrade free cyanide in wastewater, it must be able to survive and perform its primary function in the presence of such a toxicant. Chapter 4 exemplifies both molecular and biochemical characteristics of Fusarium oxysporum EKT01/02 isolated from the rhizosphere of Zea mays contaminated with a cyanide based pesticide. The molecular analyses confirmed the fungal isolate to be Fusarium oxysporum EKT01/02 and the nucleotide sequence of the isolates were deposited with National Centre for Biotechnology Information (NCBI) with accession numbers KU985430 and KU985431. The biochemical analyses revealed a wide substrate utilisation mechanism of the isolate dominated by aminopeptidase including nitrate assimilation capabilities. A preliminary investigation showed free cyanide degradation efficiency of 77.6% (100 mg CN-/L) after 5 days by the isolate. The excess production of extracellular polymeric substance (EPS) was attributed to the isolates’ strive to protect itself from cyanide toxicity.

Thesis (DTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / Industrial wastewater management pertaining to the mining industry has become increasingly stringent, with companies being required to develop environmentally benign wastewater management practices worldwide. The industries that utilise cyanide compounds for the recovery of precious and base metals in a process known as the cyanidation process, have contributed substantially to environmental deterioration and potable water reserve contamination due to the discharge of poorly treated, or untreated, cyanide containing wastewater. Hence, a biotechnological approach was undertaken in this study to remediate free cyanide (CN-) and thiocyanate (SCN-), which are the major chemical contaminants which are normally found in cyanidation wastewaters. Furthermore, this biotechnological approach was investigated to understand the fundamental aspects of using this approach such that the information gathered can be utilized in pilot plant studies. Therefore, bioprospecting of potential CN- and SCN--degrading organisms was undertaken using two approaches; (i) culture-dependent approach and (ii) culture-independent approach. Using the culture-dependent approach, Pseudomonas aeruginosa STK 03, Exiguobacterium acetylicum and Bacillus marisflavi were isolated from an oil spill site and river sediment samples, respectively. STK 03 was evaluated for the biodegradation of CN- and SCN- under alkaline conditions. The organism had a CN- degradation efficiency of 80% and 32% from an initial concentration of 250 and 450 mg CN-/L, respectively. Additionally, the organism was able to degrade SCN-, achieving a degradation efficiency of 78% and 98% from non- and CN- spiked cultures, respectively. Furthermore, the organism was capable of heterotrophic nitrification but was unable to denitrify aerobically, with the autotrophic degradation of CN- by STK 03 being abortive.

O potencial de um sistema de biopilhas em degradar resíduos oleosos provenientes de refinaria de petróleo também chamado de borra de óleo foi estudado, assim como a possibilidade de otimizar o mesmo através da bioestimulação (adição de fertilizantes) e bioenriquecimento (adição de inóculo). Primeiramente, verificou-se a biodegradabilidade do resíduo através do método respirométrico de Bartha, quantificando o CO2 emitido, observando os efeitos do uso de inóculo e de fertilizantes neste processo. Os microrganismos utilizados na produção do inóculo, fungos e bactérias, foram isolados de "landfarming" da Refinaria de Paulínia, REPLAN, estado de São Paulo, por serem adaptados ao ambiente de estresse ocasionado pelo resíduo oleoso e por terem demonstrado capacidade em biodegradar hidrocarbonetos de petróleo, em ensaios prévios realizados em laboratório. Foram construídas cinco biopilhas contendo solo poluído pela borra de óleo, nas constituições: 1 controle do experimento; 2 adicionada com inóculo; 3 com inóculo e fertilizante para plantas; 4 com inóculo e palha de arroz; 5 com inóculo, fertilizante e palha de arroz. Os resultados após 350 dias demonstraram redução da quantidade de resíduo em todas as biopilhas: 67%, 70%, 75%, 82% e 79% nas biopilhas 1, 2, 3, 4 e 5 respectivamente. As biopilhas contendo palha de arroz demonstraram degradação mais rápida do resíduo, principalmente nos dois primeiros meses deste estudo, provavelmente devido ao maior número de microrganismos que foram observados nas mesmas decorrente da adição do inóculo ou estimulação da microbiota natural. Nas condições de estudo, o inóculo adicionado nas biopilhas 2 e 3 não sobreviveram ao novo ambiente não influenciando a degradação do resíduo assim como a... (Resumo completo, clicar acesso eletrônico abaixo) / The potential of a biopile system to degradate oily residues from a petroleum refinery also called oil sludge was studied, as well as the possibility of its optimization through biostimulation (fertilizers addition) and bioaugmentation (inoculum addition). First, the biodegradability of the residue was verified through the Bartha flasks, quantifying the CO2 emitted, observing the effects of the inoculum and fertilizer use in this process. The microorganisms used in the inoculum production were isolated from the landfarming of Refinery of Paulínia, REPLAN, São Paulo State, as they are adapted to the environmental stress provoked by the oily residue showed the capacity to degradate petroleum hydrocarbons in previous assays in laboratory. Five biopiles were built with the soil polluted by the oil sludge, they were constituted by: 1 experimental control, 2 with inoculum; 3 with inoculum and plant fertilizer; 4 with inoculum and rice straw; 5 with inoculum, fertilizer and rice straw. The results after 350 days showed a reduction of the residue quantity in all the biopiles: 67%, 70%, 75%, 82% and 79% in the biopiles 1, 2, 3, 4 and 5 respectively. The biopiles containing rice straw showed a faster degradation of the residue mainly during the first two months of this study, probably due to the higher number of microorganisms provoked by the addition of the inoculum or stimulation natural microorganisms. At the conditions of this study, the addition of the inoculum to the biopiles 2 and 3 did not survive in the new environment not influencing the residue degradation, as well as the fertilizer addition did not have any influence to the biopiles 3 and 5. It was clear the importance of the addition of materials and aggregated such as the rice straw, to improve the soil characteristics regarding to aeration and permeability... (Complete abstract, access undermentioned electronic address) / Orientador: Sâmia Maria Tauk-Tornisielo / Coorientador: Ana Paula de Arruda Geraldes Kataoka / Banca: Ariovaldo José da Silva / Banca: Roberto Naves Domingos / Mestre

Orientador: Alcides Lopes Leão / Banca: Claudio Angeli Sansígolo / Banca: José Claudio Caraschi / Banca: Derval dos Santos Rosa / Banca: Elisabete Frollini / Resumo: Neste trabalho são discutidos os resultados referentes aos ensaios de biodegradabilidade de fibras naturais utilizadas pela indústria auotomobilística: fibra de coco, de coco com látex e e sisal. Estes ensaios foram realizados junto ao Laboratório de Microbiologia Industrial do Agrupamento de Biotecnologia da Divisão Química do Instituto de Pesquisas Tecnológicas do Estado de São Paulo. Apresenta-se uma revisão de literatura sobre biodegradabilidade e sobre as fibras em estudo. Realizou-se a análise elementar de CHN, a qual é um pré-requisito para o Teste da Biodegradabilidade Imediata pela Medida do Dióxido de Carbono Desprendido em Sistema Aberto (norma IBAMA - E.1.1.2. - 1998). Utilizou-se também a norma DIN 53739 (1984) - Testing of Plastics - Influence of dungi and bacteria - visual evaluation - change in mass or physical properties, baseada na ISO 846 - 1978. Fez-se a determinação de extrativos totais, de lignina, de holocelulose e do teor de cinzas das fibras em estudo para se conhecer o teor ral de lignina, celulose e hemicelulose presentes e, compreender os resultados obtidos nos testes de biodegradação. A partir do teste de biodegradabilidade (IBAMA E.1.1.2.-1998), observou-se uma taxa de biodegradação de cerca de 10% para todos os materiais em estudo após 45 dias de ensaio, demonstrando difícil degradação. Nenhum material inibiu a degradação da glicose. No entanto, a porcentagem de degradação da fibra de sisal foi superior a da fibra de coco com látex, conseiderando-se o mesmo intervalo de tempo de cultivo. Quanto a esse teste, pode-se concluir que 45 dias de ensaio é pouco tempo para a biodegradação dessas fibras naturais levando-se em consideração os teores de lignina, celulose e hemicelulose encontrados por Young (1997) para a fibra de sisal e por Han e Rowell (1997) para a fibra de coco. E, analisando-se os teores de lignina, celulose... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Presented in this study are the testing results regarding the biodegradation of natural fibres utilized by automotive industry, in this case, coir and sisal fibers, where the coir fiber was used also as rubberized mat. These biodegradation testing where carried on at th Laboratory of Industrial Microbiology by the Biotechnology Group of the Chemistry Division of the Institute of Technological Research of São paulo State - IPT. Next is presented a literatura review on biodegradation and over the studied fibers, coir and sisal, besides all the details about the testing used evaluate biodegradation and its respectively obtained results. An elementary analysis of CHN was carried out, which is a prerequisite for the Immediate Biodegradation Test of the Mesaure of the Carbon Dioxide Released in Open System (standard IBAMA - E.1.1.2. - 1998). Alson used was the standard DIN 53739 - 1984 - Testing of Plastics - influence of fungi and bacteria - visual evaluation - change in mass or physical properties, established in the ISO 846 - 1978. Also was realized the determination of total extractives, lignin, holocellulose and ash contents of the studied fibers as well as the determination of it's true content and understand the obtained biodegradation testing results. There was hence observed from the biodegradation test (standard E.1.1.2.-1998) a biodegradation tax about 10% for all the studied material after 45 days of assay, which indicates a difficult degradation. None of the material inhibited the glucose degradation. However, the percentage of sisal degradation was greater than that of the coir fiber with latex. It can be concluded about this test, that a 456 day trial is a short lapse of time for the biodegradation of these natural fibers when the contents of lignin, cellulose and hemicellulose that were found by Young (1997) for the sisal fiber and by Han and Rowell... (Complete abstract click electronic access below) / Doutor

Orientador: Carlos Renato Corso / Banca: Cassiana Maria Reganhan Coneglian / Banca: Sandra Mara Martins Franchetti / Resumo: Este trabalho apresenta uma avaliação comparativa do potencial biossortivo e biodegradativo da levedura Saccharomyces cerevisiae na remoção de corantes têxteis de efluentes quando imobilizada em alginato de cálcio e quando em célula livre. Para isto foram preparadas soluções experimentais dos corantes Acid Blue 40 e Acid Red 151, com concentrações equivalentes a 100 μg/mL e a estas foram adicionadas esferas com a levedura imobilizada a partir de uma suspensão 10% e gotas de células livres a partir de uma suspensão 2%. Os testes comparativos de remoção dos corantes foram analisados através de espectrofotômetros Ultravioleta- Visível e Infravermelho com Transformada de Fourier, com os quais foi possível determinar a porcentagem de remoção dos corantes das soluções, os valores das Absorbâncias Relativas que revelaram se o processo predominante na descoloração foi o da biossorção e/ou biodegradação, a quantidade de biomassa em miligramas (peso seco) necessária para fazer a remoção total da cor e também determinar as alterações moleculares ocorridas nas estruturas dos corantes após os tratamentos. Os resultados mostraram que a maior porcentagem de descoloração alcançada para o Acid Blue 40 foi de 61,7% após 360 horas de tratamento com 20 esferas com a levedura imobilizada e para o Acid Red 151 foi de 81,9% após 216 horas de tratamento também com 20 esferas com o microrganismo imobilizado. Através dos valores das Absorbâncias Relativas foi possível verificar que o processo predominante na remoção da cor do Acid Blue 40 com 72 horas de tratamento com 10 e 20 esferas com Saccharomyces cerevisiae imobilizada foi o da biossorção seguido da biodegradação e para o Acid Red 151 com esse mesmo tempo de tratamento e com a mesma quantidade de biomassa imobilizada foi o da biodegradação. A quantidade de biomassa imobilizada e livre... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This paper presents a comparative assessment of the biodegradative and biosorptive potential of the yeast Saccharomyces cerevisiae in textile dyes removal of effluents when in immobilized alginate and in free cells. Therefore, experimental solutions were prepared with concentrations of the dye Acid Blue 40 and Acid Red 151 equivalent to 100 mg/mL and those were added with beads containing the immobilized yeast from a 10% suspension and drops of free cells from a 2 % suspension. Comparative tests of dye removal were analyzed by UV-Visible spectrometers and Infrared Fourier Transform on which it was possible to determine the percentage of dye removal from the solutions, the values of Relatives Absorbances that the discoloration have been proved to predominant by biosorption and / or biodegradation, the amount of biomass in milligrams (dry weight) required for a complete color removal and also to determine the molecular changes occurring in the dye structures after the treatment. The results showed that the highest decolorization percentage achieved for Acid Blue 40 was 61.7% after 360 hours of treatment with 20 immobilized yeast beads and for the Acid Red 151 it was 81.9% after 216 hours of treatment with 20 beads also with immobilized microorganism. Through the values of Relatives Absorbances it was concluded that the predominant process in dye removal of Acid Blue 40 in 72 hours of treatment with 10 and 20 beads containing imobilized Saccharomyces cerevisiae was the biosorption followed by biodegradation and in Acid Red 151 with the same treatment time and the same amount of immobilized biomass it was the biodegradation. The amount of immobilized and free biomass to obtain total removal of Acid Blue 40 solution was 87 and 38 mg/mL, respectively, and to completely remove the Acid Red 151, the required amount of free and immobilized biomass was 64 and 2 mg/mL, respectively, which... (Complete abstract click electronic access below) / Mestre

A contaminação ambiental causada pelo setor têxtil apresenta um especial destaque, devido aos grandes volumes de efluentes gerados. Os tratamentos biológicos mais utilizados pelas indústrias têxteis são o lodo ativado e biofiltros, ambos com elevado custo financeiro para as indústrias, com produtos químicos e necessidade de destinação de lodo. O presente trabalho estudou a viabilidade de tratamento de efluente de indústria têxtil por MBBR “Moving Bed Biofilm Reactor” (Reator Biológico com Leito Móvel). Este processo concilia os benefícios de tratamentos antes mencionados e ao mesmo tempo reduz as características indesejáveis de elevada geração de lodo, tempo de detenção hidráulica e perda de sólidos. O efluente foi caracterizado quanto à DQO, DBO5, área espectral, sólidos suspensos totais, sólidos suspensos voláteis e toxicidade antes e após o tratamento. O tratamento do efluente ocorreu em diferentes cargas orgânicas volumétricas, de 0,3gDQO/L.d até 9,0g DQO/L.d com 4 estágios: adaptação (0,3gDQO/L.d) e outros 3 estágios (1,2gDQO/L.d, 3,0gDQO/L.d e 9,0gDQO/L.d). Este reator foi operado por 107 dias, alcançando remoções de 65% de DQO, 94% de DBO5, 58% de área espectral, 82% de SST e 87% de toxicidade. Resultados que foram avaliados pela ANOVA, com teste Tukey com 0,05 de significância. A cinética calculada do processo apresentou consumo especifico máximo de substrato de 0,027d-1, compatível a tratamentos biológicos de efluente com conteúdo recalcitrante. Através dessas análises foi verificado que os melhores resultados de remoção foram atingidos quando o reator foi operado em COVs menores. / The environment contamination caused by the textile sector has a special meaning due to volumes of wastewater. The biological treatments most commonly used by textile industries are biofilters and activated sludge, both with a high financial cost for industries with chemicals products and the need for sludge disposal. This work studied the viability of treatment of textile effluent´s by MBBR "Moving Bed Biofilm Reactor". This process combines the benefits of treatments mentioned above and at the same time reduces undesirable characteristics of high sludge generation, hydraulic retention time and solids loss. The effluent was characterized as COD, BOD5, spectral area, total suspended solids, volatile suspended solids and toxicity before and after treatment. The treatment of the effluent occurred in different organic loading rates from 0.3 gCOD/L.d up to 9.0 g COD/L.d with 4 stages: adaptation 0.3gCOD/L.d and others 3 stages 1.2gCOD/L, 3.0 gCOD/L and 9.0gCOD/L.d. This reactor was operated for 107 days, reaching 65% removal of COD, 94% of BOD5, 58% of spectral area, 82% of TSS and 87% of toxicity. The results were evaluated by ANOVA with Tukey's test at 0.05 significance level. The calculated kinetics of the process presented consumption specific maximum of substrate of 0,027d-1, compatible with biological treatment effluent with recalcitrant content. Through these analyzes it was verified that the best removing results were achieved when the reactor was operated at lower OLRs.

A utilização do metano (CH4) presente no biogás gerado através da degradação anaeróbica de resíduos orgânicos depositados em aterros sanitários como fonte de energia é uma tecnologia em expansão, principalmente nos países em desenvolvimento. Para assegurar um melhor aproveitamento do CH4 e a viabilidade econômica do projeto de exploração energética é necessário que estes empreendimentos avaliem sua capacidade de produzir este gás com o passar dos anos, mesmo após o encerramento da deposição de resíduos. O potencial de geração é comumente estimado a partir de modelos cinéticos de primeira ordem propostos por conceituadas instituições, entretanto, estudos recentes apontam alto grau de incerteza e diferenças relevantes entre os resultados obtidos com cada metodologia. Este trabalho tem por objetivo analisar a variação dos resultados das estimativas de emissão de metano dos modelos recomendados pela USEPA, Banco Mundial (Scholl Canyon) e IPCC utilizando tanto dados e informações disponibilizadas do aterro sanitário Moskogen, localizado em Kalmar, Suécia, que foi operado entre 1977 e 2008. Além de estimar a capacidade de geração de CH4, objetiva-se identificar qual o modelo cujas estimativas mais se aproximam dos dados de biogás efetivamente medidos e quanto gás ainda pode ser extraído do aterro. O estudo ainda avaliou como valores diferentes para os parâmetros principais dos modelos afetam a estimativa de geração final. O modelo IPCC mostrou-se o mais confiável dentre os analisados, estimando que o aterro Moskogen produza mais de 102 milhões de m de CH4 entre 1977 e 2100, sendo 39,384 milhões passíveis de extração de 2012 a 2100. Os demais modelos apresentaram premissas inadequadas com a realidade do aterro sanitário estudado. Contudo, mesmo com a superioridade do modelo proposto pelo IPCC, maiores estudos são necessários no local, que levantem outras informações de campo como a vazão passiva de gás pela camada de cobertura do aterro e uma melhor estimativa do percentual de material orgânico biodegradável presente em cada fração de resíduos depositada em Moskogen. / The use of methane (CH4) present in the biogas generated by the anaerobic degradation of organic wastes in landfills as an energy source is an expanding technology, especially in developing countries. To ensure a proper utilization of CH4 and the economic feasibility of the energy recovery project it is necessary that these landfills evaluate their capability to produce this gas over the years, even after the end of waste disposal. The generation potential is commonly estimated from first-order kinetic models proposed by reputable institutions, however, recent studies indicate a high level of uncertainty and significant differences between the results obtained with each method. This study aims to analyze the variation of the results of methane generation estimatives, from the models recommended by the USEPA, the World Bank (Scholl Canyon Model) and the IPCC using field data and information provided by Moskogen landfill, located in Kalmar, Sweden, which was operated from 1977 to 2008. In addition to estimating the CH4 generation potential, the objective is to identity which model whose results are closer to the data of the amount of biogas effectively measured and to discover how much gas still can be extracted from the landfill. The study also evaluated how different values to the model main parameters affect the final generation estimative. The IPCC model proved to be the most reliable among the others analyzed, estimating that Moskogen will produce over 102 million m of CH4 between 1977 and 2100, which 39.384 can be extracted from 2012 to 2100. The other models presented inadequate assumptions in comparison to the reality of the studied landfill. Nevertheless, despite the fact that the model proposed by the IPCC has been judged as the most faithful, larger studies are needed on the area, in order to identify more field data, such as the occurrence of passive gas flow through the top covering layers of the landfill and a better estimative of the amount of degradable organic compounds in each fraction of waste disposed in Moskogen.

A contaminação ambiental causada pelo setor têxtil apresenta um especial destaque, devido aos grandes volumes de efluentes gerados. Os tratamentos biológicos mais utilizados pelas indústrias têxteis são o lodo ativado e biofiltros, ambos com elevado custo financeiro para as indústrias, com produtos químicos e necessidade de destinação de lodo. O presente trabalho estudou a viabilidade de tratamento de efluente de indústria têxtil por MBBR “Moving Bed Biofilm Reactor” (Reator Biológico com Leito Móvel). Este processo concilia os benefícios de tratamentos antes mencionados e ao mesmo tempo reduz as características indesejáveis de elevada geração de lodo, tempo de detenção hidráulica e perda de sólidos. O efluente foi caracterizado quanto à DQO, DBO5, área espectral, sólidos suspensos totais, sólidos suspensos voláteis e toxicidade antes e após o tratamento. O tratamento do efluente ocorreu em diferentes cargas orgânicas volumétricas, de 0,3gDQO/L.d até 9,0g DQO/L.d com 4 estágios: adaptação (0,3gDQO/L.d) e outros 3 estágios (1,2gDQO/L.d, 3,0gDQO/L.d e 9,0gDQO/L.d). Este reator foi operado por 107 dias, alcançando remoções de 65% de DQO, 94% de DBO5, 58% de área espectral, 82% de SST e 87% de toxicidade. Resultados que foram avaliados pela ANOVA, com teste Tukey com 0,05 de significância. A cinética calculada do processo apresentou consumo especifico máximo de substrato de 0,027d-1, compatível a tratamentos biológicos de efluente com conteúdo recalcitrante. Através dessas análises foi verificado que os melhores resultados de remoção foram atingidos quando o reator foi operado em COVs menores. / The environment contamination caused by the textile sector has a special meaning due to volumes of wastewater. The biological treatments most commonly used by textile industries are biofilters and activated sludge, both with a high financial cost for industries with chemicals products and the need for sludge disposal. This work studied the viability of treatment of textile effluent´s by MBBR "Moving Bed Biofilm Reactor". This process combines the benefits of treatments mentioned above and at the same time reduces undesirable characteristics of high sludge generation, hydraulic retention time and solids loss. The effluent was characterized as COD, BOD5, spectral area, total suspended solids, volatile suspended solids and toxicity before and after treatment. The treatment of the effluent occurred in different organic loading rates from 0.3 gCOD/L.d up to 9.0 g COD/L.d with 4 stages: adaptation 0.3gCOD/L.d and others 3 stages 1.2gCOD/L, 3.0 gCOD/L and 9.0gCOD/L.d. This reactor was operated for 107 days, reaching 65% removal of COD, 94% of BOD5, 58% of spectral area, 82% of TSS and 87% of toxicity. The results were evaluated by ANOVA with Tukey's test at 0.05 significance level. The calculated kinetics of the process presented consumption specific maximum of substrate of 0,027d-1, compatible with biological treatment effluent with recalcitrant content. Through these analyzes it was verified that the best removing results were achieved when the reactor was operated at lower OLRs.

O cianeto é um composto tóxico, que pode ser encontrado no ambiente de maneira natural ou como resultado de atividades antropogênicas tais como a mineração de ouro e a indústria da galvanoplastia. Dentre as diferentes espécies do composto, o cianeto de hidrogênio (HCN) é considerado o mais tóxico, mesmo concentrações de 100ppm são letais para os seres humanos. Para a degradação destes compostos de cianeto a compostos menos tóxicos existem diferentes métodos de tratamento que podem ser químicos, físicos ou biológicos. O presente trabalho estudou a capacidade de degradação bacteriana de cianeto com cepas nativas isoladas de rejeito de mineração de ouro. Para isto, foram escolhidas três cepas dentro de um grupo de vinte cepas isoladas previamente. As cepas foram identificadas mediante as técnicas de MALDI-TOF e sequenciamento do gene 16s. Posteriormente realizou-se o processo de ativação e crescimento bacteriano no qual foram determinados os parâmetros de crescimento para cada uma das cepas, tais como pH, agitação, temperatura e meio de cultura. Após a etapa de ativação bacteriana, realizou-se a adaptação das três cepas em ambientes alcalinos. Nesta etapa, foram feitos ensaios em frascos agitados e avaliou-se o crescimento celular em função da formação de células viáveis para diferentes condições de pH (7; 8; 9,10 e 11). Com as cepas adaptadas ao pH 10 foram realizados ensaios de degradação bacteriana de cianeto em frascos agitados contendo 100mL de solução sintética de cianeto de potássio e 0,2mL de inoculo bacteriano. A concentração da solução de cianeto foi de 500mgL-1 e o pH de 10. Foram avaliadas três condições de temperatura (37, 32 e 27oC). Durante os ensaios foi estudado o crescimento bacteriano, o comportamento do pH e a degradação de cianeto. A quantificação do cianeto livre foi determinada pelo método polarográfico com eletrodo de mercúrio. Através dos resultados obtidos, foi possível identificar que as três cepas isoladas pertencem ás espécies Bacillus pumilus, Bacillus licheniformis e Bacillus subtilis. As cepas bacterianas apresentaram maior produção celular quando cultivadas em meio L.B a pH 7, velocidade de rotação de 190rpm e 37oC de temperatura. A máxima faixa de adaptação a ambientes alcalinos aconteceu em valores de pH 10. As melhores taxas de degradação de cianeto para a cepa B. subtilis e B. pumilus ocorreram em temperatura de 27oC e 65rpm, conseguindo degradar 100% do cianeto. A cepa B. licheniformis apresentou a melhor taxa de degradação de cianeto em temperatura de 32oC e 190rpm obtendo 99,5% de degradação. Através dos resultados obtidos no presente trabalho, foi possível avaliar o potencial de degradação de cianeto para as bactérias B. pumilus, B. licheniformis e B. subtilis as quais podem ser utilizadas como alternativa de tratamento em efluentes contaminados com cianeto. / Cyanide is a highly toxic compound that can be naturally found in the environment or as a result of anthropogenic activities such as gold mining and electroplating industry. Among the different species of the compound, hydrogen cyanide (HCN) is considered the most toxic, even concentrations of 100 ppm are lethal to humans. Degradation of this cyanide compound to less toxic compounds can be carried out through different methods such as chemical, physical and biological treatments. The present work investigated the bacterial degradation capacity of cyanide by isolated native strains from gold mining tailings. Three strains were selected from a group of twenty previously isolated strains which were identified using MALDI-TOF and 16s gene sequencing techniques. The bacterial activation and cellular growth were performed to determine the growth parameters for the strains, such as pH, temperature, rotation speed and culture medium. After the activation, the strains were adapted to grow in alkaline environments. During this phase, cellular growth was carried out in agitated flask at different pHs (7, 8, 9, 10 and 11). The adapted strains were used to perform cyanide degradation tests at pH 10 in agitated flask by using 100mL of a synthetic solution. The solution was composed of 500 ppm of potassium cyanide and 0,2mL of bacterial inoculum. During the experiments, three temperatures were evaluated (37, 32 and 27°C). Bacterial growth, cyanide degradation and pH behaviour were studied Free cyanide quantification was determined by polarographic method with a mercury electrode. It was found that the three isolated strains belong to Bacillus pumilus, Bacillus licheniformis and Bacillus subtilis groups. The highest bacterial growth was observed when the strains were cultivated in a L.B media at pH 7,0, 37°C by using 190 rpm of rotation velocity. The maximum range of adaptation to alkaline environments occurred in pH values of 10. The best cyanide degradation rate (100%) were achieved at 27°C for the strain B. suptilis and B. pumilus. The strain. B. licheniformis showed the best cyanide degradation rate (99,5%) at 37°C. The results obtained in the present work were able to evaluate the potential of cyanide degradation for the bacteria B. pumilus, B. licheniformis and B. subtilis. These results can be used as an alternative to treat wastewaters that are polluted with cyanide.