There is general concern whether human exposure to selected Canadian bottled waters and the chemicals which may leach from them, could potentially cause deleterious effects. This research was designed to determine whether exposures to bottled water and plastic leachates caused toxicity to the freshwater Cnidarian Hydra viridissima (green hydra). Three chemicals used in the production of polycarbonate and polyethylene plastics, bisphenol A (BPA) and two phthalate esters: dibutyl phthalate (DBP) and bis (2- ethylhexyl) phthalate (DEHP) along with one type of commercial bottled water were investigated. One brand of bottled water was analyzed over four months (stored in light and dark conditions) along with lab water similarly stored in glass, polycarbonate and polyethylene bottles. Following 2, 4, 8 and 16 weeks in each of the two treatments, hydra bioassays were conducted. Chronic toxicity tests were also conducted on the two phthalates and BPA. The chronic toxicity tests showed that BPA caused effects on hydra morphology and population at low doses and DBP and DEHP both showed signs of hormesis.

Sponge population partly depends on larval recruitment. Environmental factors, e.g. light, salinity, pH and temperature, chemical factors and pollution may influence larval settlement and metamorphosis. In this study, the effects of galaxolide¡]HHCB¡^¡Btonalide¡]AHTN¡^and bisphenol A¡]BPA¡^on the settlement and metamorphosis of an intertidal sponge ¡]Spongia ceylonensis¡^ were examined. The experiments included LC50 test, effects of solvent, HHCB, AHTN and BPA on sponge settlement and metamorphosis. In the LC50 tests, the 96 hr¡VLC50 value of HHCB and AHTN all greater than 1.00 mg/L, and the 96 hr¡VLC50 of BPA was 0.58 mg/L. Acetone concentration (1.00 mg/L ) in this study didn¡¦t affect sponge settlement and metamorphosis. Effect of HHCB and AHTN on sponge settlement and metamorphosis concentrations of 0.13, 0.25, 0.50 and 1.00 mg/L was insignificant. In contrast, the settlement rate was decrease by 20 % at treatment of 1.00 mg/L BPA. The metamorphosis rates were also decrease by 20 % and 80 % at concentrations of 0.50 mg/L and 1.00 mg/L BPA. In conclusion, the toxicity of AHTN was greater than that of HHCB to sponge settlement and metamorphosis.

Tetrabromobisphenol A, (TBBPA or Br4BPA), is a widely used brominated flame retardant (BFR). Although TBBPA and its breakdown products been found in river sediments, the environmental impact of their contamination is largely unknown. One breakdown product of TBBPA is bisphenol A (BPA), which has been studied intensively for its toxicology because it is used in the manufacturing of plastics and leaches from food containers, water bottles and pipes. Other breakdown products of TBBPA include tribromobisphenol A (Br3BPA), dibromobisphenol A (Br2BPA), and monobromobisphenol A (BrBPA) but little is known about their toxicology. Since TBBPA is toxic, there is a need to search for an alternative BFR, with one being tetrabromobisphenol A bis(2,3-dibromopropylether) or TBBPA-DBPE. However, almost nothing is known about the toxicology of this compound. Hence, two rainbow trout cell lines, RTL-W1 from liver and RTgill-W1 from gill, were used to evaluate the cellular toxicity of TBBPA, BPA, BrBPA, Br2BPA, Br3BPA and TBBPA-DBPE. The cells were exposed to these compounds for 24 h in the basal medium, L-15, to study their cytotoxicity and in L-15 with fetal bovine serum (FBS) to evaluate their capacity to induce 7-ethoxyresorufin o-deethylase (EROD) activity. Viability was measured with three fluorometric indicator dyes: Alamar Blue (AB) for metabolism, 5-carboxyfluorescein diacetate acetoxymethyl (CFDA AM) for cell membrane integrity, and Neutral Red (NR) for lysosomal activity. The concentrations causing a 50 % reduction in viability (EC50) as measured with these three dyes were used to compare the relative cytotoxicity of these chemicals. For both cell lines and with all viability endpoints, TBBPA was the most cytotoxic, with EC50s ranging from 2.33 to 3.11 ug/ml. BPA, BrBPA, Br2BPA, and Br3BPA also caused dose-dependent declines in cell viability but showed no consistent order of potency. None of the six compounds induced EROD activity, which suggests that they do not activate the aryl hydrocarbon receptor (AhR). Regardless of the endpoint or cell line, TBBPA-DBPE was not cytotoxic. This suggests that, from a toxicological perspective, this compound may be a suitable replacement for TBBPA as a BFR. BPA stood out from the other compounds in two regards. BPA caused a dose-dependent decline in cell viability for cultures in L-15 with FBS, whereas for the other compounds, little or no change in viability was seen in cultures with FBS. BPA elicited a decline in the ability of cells to reduce AB almost immediately upon its addition to cultures in a simple buffer, whereas as for other compounds a decline took time to develop. These results suggest that BPA exerts its cytotoxicity by a different mechanism different from the other compounds.

Magister Scientiae - MSc (Chemistry) / Electrochemical platforms were developed based on pencil graphite electrodes (PGEs) modified electrochemically with reduced graphene oxide metal nanoparticles (ERGO-metalNPs) composite and used for the high-sensitivity determination of Bisphenol A (BPA) in water samples. Synergistic effects of both reduced Graphene Oxide sheets and metal nanoparticles on the performance of the pencil graphite electrode (PGE) were demonstrated in the oxidation of BPA by differential pulse voltammetry (DPV). A solution of graphene oxide (GO) 1 mg mL-1 and 15 ppm of metal stock solutions (1,000 mg L-1, atomic absorption standard solution) (Antimony or Gold) was prepared and after sonication deposited onto pencil graphite electrodes by cyclic voltammetry reduction. Different characterization techniques such as FT-IR, HR-SEM, XRD and Raman spectroscopy were used to characterize the GO and ERGO-metalNPs. Parameters that influence the electroanalytical response of the ERGO-SbNPs and ERGO-AuNPs such as, pH, deposition time, deposition potential, purging time were investigated and optimized. Well-defined, reproducible peaks with detection limits of 0.0125 ?M and 0.062 ?M were obtained for BPA using ERGO-SbNPs and ERGO-AuNPs respectively. The rGO-metalNPs-PGE was used for the quantification of BPA in tap water sample and proved to be suitable for the detection of BPA below USEPA prescribed drinking water standards of 0.087 ?M. / 2021-12-31

Magister Scientiae - MSc (Chemistry) / Electrochemical platforms were developed based on pencil graphite electrodes (PGEs) modified electrochemically with reduced graphene oxide metal nanoparticles (ERGO–metalNPs) composite and used for the high-sensitivity determination of Bisphenol A (BPA) in water samples. Synergistic effects of both reduced Graphene Oxide sheets and metal nanoparticles on the performance of the pencil graphite electrode (PGE) were demonstrated in the oxidation of BPA by differential pulse voltammetry (DPV). A solution of graphene oxide (GO) 1 mg mL-1 and 15 ppm of metal stock solutions (1,000 mg L-1, atomic absorption standard solution) (Antimony or Gold) was prepared and after sonication deposited onto pencil graphite electrodes by cyclic voltammetry reduction. Different characterization techniques such as FT-IR, HR-SEM, XRD and Raman spectroscopy were used to characterize the GO and ERGO–metalNPs. Parameters that influence the electroanalytical response of the ERGO–SbNPs and ERGO–AuNPs such as, pH, deposition time, deposition potential, purging time were investigated and optimized. Well-defined, reproducible peaks with detection limits of 0.0125 μM and 0.062 μM were obtained for BPA using ERGO–SbNPs and ERGO–AuNPs respectively. The rGO-metalNPs–PGE was used for the quantification of BPA in tap water sample and proved to be suitable for the detection of BPA below USEPA prescribed drinking water standards of 0.087 μM.

Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-15Bitstream added on 2014-06-13T19:05:18Z : No. of bitstreams: 1 montagner_e_dr_araiq.pdf: 2830486 bytes, checksum: 76237dd3b48ac6739011b71ca2d09a40 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Bisfenol A (BFA) é um monômero formado por dois anéis fenólicos e empregado na produção de plástico policarbonato e resinas epóxi. O policarbonato é amplamente empregado na fabricação de vários produtos dos meios digitais (CD e DVD), recipientes reusáveis de alimentos e bebidas e muitos outros produtos. As resinas epóxi são usadas em circuitos elétricos, pinturas, adesivos, revestimentos protetores de latas de alimentos e bebidas e complexos dentários para obturações. Estudos revelaram que o BFA age nos organismos vivos com efeitos de desregulação endócrina, como um xenobiótico com ação estrogênica, provocando aumento da incidência de câncer de mama, queda da quantidade de esperma, diminuição da fertilidade, defeitos congênitos secundários à exposição fetal e outras alterações. O BFA chega ao ambiente aquático por inúmeras vias distintas como, por exemplo, vindo do lodo proveniente de esgoto, da descarga de esgotos domésticos e industriais, dos lixões e aterros sanitários não controlados. Neste trabalho, desenvolveu-se e validou-se um método para a determinação de BFA em águas superficiais e de abastecimento à população de Campo Grande - MS, utilizando-se extração em fase sólida EFS (cartuchos de fase polimérica Strata-X), derivação com N O-Bis-(trimetilsilil) trifluroacetamida (BSTFA) e detecção por cromatografia a gás acoplada à espectrometria de massas. A precisão e a exatidão do método foram avaliadas em de ensaios de recuperação. Recuperações variando de 91 a 113% com coeficientes de variação percentuais inferiores a 8,9% foram obtidos com limites de detecção e quantificação do método de 2,4 e 10 ng L-1, respectivamente. Também foi avaliada a conservação do BFA nos próprios cartuchos de EFS onde se observou que este analito pode ser armazenado por até 90 dias sem diferenças significativas entre o valor... / Bisphenol A (BPA) is a monomer consisting of two phenolic rings and employed in the production of polycarbonate plastic and epoxy resins. The polycarbonate is widely used in many manufactured products from digital media (CD and DVD), reusable containers food and beverages and many other products. Epoxy resins are used in electrical circuits, paints, adhesives, protective coatings for cans of food, drinks and complex dental fillings. Studies have shown that BPA acts in living organisms with the purpose of endocrine disrupting as a xenobiotic with estrogenic action, causing an increased incidence of breast cancer, decrease the amount sperm, fertility decreased, birth defects secondary to fetal exposure and other changes. BPA reaches the aquatic environment by several distinct pathways, for example, coming from the sludge sewage, discharge of domestic sewage and industrial waste dumps and the landfills. In this work, we developed and validated a method for the determination of BPA in surface water and supply population of Campo Grande – MS was developmente ande validated using solid phase extraction SPE (polymeric phase cartridges Strata-X), derivatized with N-O-Bis (trimethylsilyl) trifluroacetamide (BSTFA) and detection by gas chromatography coupled to mass spectrometry. The precision and accuracy of method were evaluated through recovery experiments. Recoveries ranging from 91-113% with coefficients of variation lower to 8.9% were obtained with limits of detection and quantification of 2.4 and 10 ng L-1, respectively. We also analyzed the estability of BPA in individual cartridges SPE where it was observed that the analyte can be stored for up to 90 days without significant differences between the determined and the value taken as true. The leaching of BPA from PVC pipes was investigated coming to conclusions that this is a source contamination of water by this important endocrine... (Complete abstract click electronic access below)

O bisfenol-A (BPA), um monômero usado na fabricação de resinas epóxi e de plásticos de policarbonato, é considerado um potente desregulador endócrino que provoca diversas doenças. O objetivo deste trabalho foi estudar a remoção de BPA, de soluções aquosas através da técnica de adsorção em batelada e em processo contínuo. Também foi investigada a capacidade de regeneração do sorvente utilizado nos testes em batelada. Para isso, foram testados diferentes adsorventes (zeólita em pó e granular modificada com quitosana, zeólita sódica e carvão ativado granular), a fim de determinar qual apresentaria maiores índices de remoção de BPA. Posteriormente foram realizados ensaios de sorção com o sólido escolhido objetivando encontrar as condições mais adequadas de processo considerando os parâmetros de pH, tempo de residência, concentração de sólido sorvente. Ainda, isotermas de equilíbrio para este sistema foram construídas. A adsorção em leito fixo foi avaliada em experimentos via planta piloto de adsorção, segundo a influência de três variáveis: efeito da massa de adsorvente utilizada (5g e 10g), vazão de alimentação (15 mL.min-1 e 20 mL.min-1) e concentração inicial (50 mg.L-1 e 100 mg.L-1). Na regeneração do carvão ativado saturado com BPA, empregaram-se como solventes acetona, n-pentano e diclorometano e também foi utilizada a técnica de ultrassom. As condições de sorção utilizadas foram: pH 6, tempo 60 min, concentração de sorvente 10 g.L-1 e soluções de BPA 10 mg.L-1. A microestrutura externa e a composição elementar semi-quantitativa do carvão ativado antes e após o processo de sorção e regeneração foram analisadas pela técnica de MEV-EDS. No que se refere à sorção, melhores resultados foram encontrados com o carvão ativado granular, atingindo eficiência de remoção de 56,7% em pH 7. O modelo de isoterma de sorção que melhor se ajustou aos dados experimentais foi o modelo de Sips, que forneceu a constante de energia ou afinidade do processo e também a acumulação máxima de BPA no sorvente. Os testes de regeneração mostraram que os melhores agentes regenerativos foram a acetona (100%), com eficiência de remoção de 105,6% e a técnica de ultrassom, a qual apresentou uma eficiência de remoção de 106,4% após um tempo de contato de 30 min. Por ser uma técnica que não gera resíduo, optou-se utilizar o ultrassom para os testes de regeneração em ciclos. O ensaio de tempo de regeneração em banho de ultrassom mostrou que para os tempos de 30, 40, 50 e 60 min de contato a regeneração era muito semelhante. Assim, para os testes de ciclos de sorção-regeneração o tempo de contato utilizado foi de 30 min. Os ensaios de regeneração em ciclos mostraram que após seis (6) ciclos a eficiência de regeneração do sólido sorvente foi de 67,8% e a remoção de BPA obtida ao final desses ciclos foi de 60,9%. Quanto à caracterização do sorvente, as micrografias mostraram que o carvão ativado, antes e após os ciclos de sorção/regeneração (S/R), possui superfícies bastante irregulares, heterogêneas e desordenadas, com elevada porosidade. Ensaios realizados em planta piloto de adsorção mostraram a viabilidade técnica de aplicação do carvão ativado para remoção de bisfenol em processos contínuos, tendo sido possível obter as condições operacionais e a curva de ruptura do sistema. Os resultados indicaram que a adsorção em leito fixo apresentou melhores resultados nas seguintes condições: vazão de alimentação de 20 mL.min-1, concentração inicial de 100 mg.L-1 e 10g de sólido sorvente. / The bisphenol-A (BPA), a monomer used in the manufacture of epoxy resins and polycarbonate plastics is considered a powerful endocrine disrupter which causes various diseases. The objective of this work was to study the removal of BPA from aqueous solutions by adsorption technique in batch and continuous process. The regeneration capacity of sorbents used in batch tests was also investigated. For this purpose, different adsorbents were initially tested (zeolite powder and granular modified with chitosan, sodium zeolite and granular activated carbon) in order to determine which one presents higher removal rates of BPA. After that, sorption tests were carried out with the chosen solid aiming to find the best process conditions considering pH, residence time and sorbent concentration. Hence, equilibrium isotherms were constructed for this system. The fixed bed adsorption was evaluated through adsorption experiments using a pilot plant, according to the influence of three variables: the effect of the mass of the used adsorbent (10g and 5g), flow rate (15 mL.min-1 and 20 mL.min-1) and initial concentration (50 mg.L-1 and 100 mg.L-1). In activated carbon regeneration it was employed acetone, n-pentane and dichloromethane as solvents and the ultrasound technique was also used. The applied sorption conditions were the following: pH 6, time 60 min, sorbent concentration of 10 g.L-1 and BPA solution of 10 mg.L-1. The external microstructure and semi-quantitative elemental composition of the activated carbon before and after the sorption and regeneration were analyzed by SEM-EDS technique. Concerning sorption, the best results were found with granular activated carbon, reaching removal efficiency of 56.7% at pH 7. The sorption isotherm model that best fit the experimental data was the Sips model, which provided constant energy or affinity of the process and also the maximum accumulation of BPA in the sorbent. The regeneration tests showed that the best agents of regeneration were acetone (100%), with removal efficiency of 105.6% and the ultrasound technique, which presented a removal efficiency of 106.4% after a contact time of 30 min. Considering that the technique doesn’t generates waste, it was decided to use the ultrasound tests for regeneration cycles. The regeneration test time in ultrasound bath showed that for contact times of 30, 40, 50 and 60 min the regeneration was very similar. Thus, for testing cycles of sorption-regeneration, the used contact time was 30 minutes. The regeneration cycle tests showed that after six (6) cycles of regeneration efficiency of the solid sorbent was 67.8% and the removal of BPA obtained at the end of these cycles was 60.9%. Regarding characterization of the sorbent, the micrographs showed that the activated carbon before and after cycles of sorption/regeneration (S/R), has very irregular, heterogeneous and disordered surfaces with high porosity. Tests carried out in a pilot plant adsorption showed the technical viability of application of the activated carbon for removal of bisphenol in continuous processes, thus it is possible to obtain operating conditions and the breakthrough curve for this system. These results indicate that the fixed bed adsorption presents best results in the following conditions: feed flow rate of 20 mL.min-1, initial concentration of 100 mg.L-1 and 10 g of solid sorbent.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O policarbonato de bisfenol A (PCBFA) à um poliÃster, com repetiÃÃo de estrutura quÃmica das molÃculas de bisfenol A (BFA), que acumula um conjunto bem balanceado de propriedades, tais como: transparÃncia, estabilidade tÃrmica e dimensional, resistÃncia mecÃnica, antichama; permitindo classificÃ-lo como plÃstico de engenharia. Ele à um material utilizado em garrafÃes retornÃveis para acondicionamento de Ãgua mineral. O processo de fabricaÃÃo dos garrafÃes à de grande importÃncia, pois objetiva a produÃÃo de um material uniforme, que de certa maneira garante qualidade para resistir Ãs intempÃries do tempo e aos diversos processos de envasamento de Ãgua, estocagem e distribuiÃÃo. Os ÃrgÃos governamentais regulamentaram que o tempo de vida Ãtil das embalagens à somente de trÃs anos. A validade da Ãgua em garrafÃes lacrados varia de 60 a 120 dias. Depois de aberto, a recomendaÃÃo à consumir em atà duas semanas. A degradaÃÃo do PCBFA foi estudada utilizando garrafÃes de 20 litros de diferentes anos de fabricaÃÃo (0-15 anos), observou-se o efeito do tempo na mudanÃa das caracterÃsticas e propriedades do material. Verificou-se que a espessura dos garrafÃes diminui com o tempo de fabricaÃÃo. A partir de 8 anos de fabricaÃÃo, possÃveis mudanÃas estruturais, como a descarboxilaÃÃo, diminuiÃÃo da temperatura de transiÃÃo vÃtrea e alteraÃÃo nas propriedades mecÃnicas foram constatadas atravÃs das tÃcnicas de infravermelho (FTIR), Calorimetria ExploratÃria Diferencial (DSC) e por ensaios mecÃnicos de traÃÃo, respectivamente. Por microscopia eletrÃnica de varredura (MEV), verificou-se que a superfÃcie externa apresentou-se com mais alteraÃÃes morfolÃgicas em relaÃÃo à superfÃcie interna. Por anÃlise termogravimÃtrica (TGA), notou-se que o PCBFA da superfÃcie interna tem uma menor estabilidade tÃrmica que a superfÃcie externa do garrafÃo. Por anÃlise de fluorescÃncia foi detectada a presenÃa de BFA em Ãgua destilada mantida em contato com o garrafÃo estocada durante 2 meses. O BFA à o reagente utilizado na sÃntese industrial do PCBFA onde o mesmo à um desregulador endÃcrino que causa alteraÃÃes hormonais no sistema endÃcrino. Pode-se concluir que os garrafÃes de PCBFA sofrem degradaÃÃo com o passar dos anos a ponto do material perder suas principais propriedades, tanto na superfÃcie externa e interna. A relevÃncia maior do estudo evidencia sobre a validade dos garrafÃes e a possÃvel liberaÃÃo de BFA na Ãgua. / The polycarbonate of bisphenol A (PCBFA) is a polye ster with repeating chemical structure of molecules of bisphenol A (BFA), which accumulates a well-balanced set of properties, such as transparency, thermal and dimen sional stability, mechanical strength, flame retardant; allowing classify it as engineerin g plastic. It is a material used in returnable carboys for packaging of mineral water. The manufacturing process of the carboys is of great importance, because it aims the production of a uniform material, which somehow ensures quality to withstand the incl ement weather of weather and the various processes of potting water, stocking and di stribution of carboys. Government agencies have regulated that the time of validity o f the carboys is only three years. The validity of water in sealed bottles ranges from 60 to 120 days. Once opened, the recommendation is to consume within two weeks. The degradation was studied using PCBFA of 20 liters carboys of different fabrication years (0-15 years), we observed the effect of time in changing of the characteristics a nd properties of material. It was found that the thickness of carboys lowers with time of f abrication. From 8 years of manufacturing, possible structural changes, such as decarboxylation, reduction in glass transition temperature and changes in mechanical pr operties were observed via infrared techniques (FTIR), differential scanning calorimetr y (DSC) and tensile test, respectively. By scanning electron microscopy, it w as found that the external surface appeared with more morphological changes in relatio n to the inner surface. By thermogravimetric analysis (TGA), it was noted that the PCBFA the inner surface has a lower thermal stability than the outer surface of t he carboy. By fluorescence analysis, we detected the presence of BFA in distilled water kept in contact with the stored carboy for 2 months. BFA is the reagent used in the industrial synthesis of PCBFA where it is an endocrine disrupter which causes hor monal changes in the endocrine system. It can be concluded that the polycarbonate carboys undergo degradation with passing of the years to the point of the material l osing its main properties, both the outer and inner surface. The most relevant study demonstr ates the validity of carboys and the possible release of BFA in the water

O bisfenol-A (BPA), um monômero usado na fabricação de resinas epóxi e de plásticos de policarbonato, é considerado um potente desregulador endócrino que provoca diversas doenças. O objetivo deste trabalho foi estudar a remoção de BPA, de soluções aquosas através da técnica de adsorção em batelada e em processo contínuo. Também foi investigada a capacidade de regeneração do sorvente utilizado nos testes em batelada. Para isso, foram testados diferentes adsorventes (zeólita em pó e granular modificada com quitosana, zeólita sódica e carvão ativado granular), a fim de determinar qual apresentaria maiores índices de remoção de BPA. Posteriormente foram realizados ensaios de sorção com o sólido escolhido objetivando encontrar as condições mais adequadas de processo considerando os parâmetros de pH, tempo de residência, concentração de sólido sorvente. Ainda, isotermas de equilíbrio para este sistema foram construídas. A adsorção em leito fixo foi avaliada em experimentos via planta piloto de adsorção, segundo a influência de três variáveis: efeito da massa de adsorvente utilizada (5g e 10g), vazão de alimentação (15 mL.min-1 e 20 mL.min-1) e concentração inicial (50 mg.L-1 e 100 mg.L-1). Na regeneração do carvão ativado saturado com BPA, empregaram-se como solventes acetona, n-pentano e diclorometano e também foi utilizada a técnica de ultrassom. As condições de sorção utilizadas foram: pH 6, tempo 60 min, concentração de sorvente 10 g.L-1 e soluções de BPA 10 mg.L-1. A microestrutura externa e a composição elementar semi-quantitativa do carvão ativado antes e após o processo de sorção e regeneração foram analisadas pela técnica de MEV-EDS. No que se refere à sorção, melhores resultados foram encontrados com o carvão ativado granular, atingindo eficiência de remoção de 56,7% em pH 7. O modelo de isoterma de sorção que melhor se ajustou aos dados experimentais foi o modelo de Sips, que forneceu a constante de energia ou afinidade do processo e também a acumulação máxima de BPA no sorvente. Os testes de regeneração mostraram que os melhores agentes regenerativos foram a acetona (100%), com eficiência de remoção de 105,6% e a técnica de ultrassom, a qual apresentou uma eficiência de remoção de 106,4% após um tempo de contato de 30 min. Por ser uma técnica que não gera resíduo, optou-se utilizar o ultrassom para os testes de regeneração em ciclos. O ensaio de tempo de regeneração em banho de ultrassom mostrou que para os tempos de 30, 40, 50 e 60 min de contato a regeneração era muito semelhante. Assim, para os testes de ciclos de sorção-regeneração o tempo de contato utilizado foi de 30 min. Os ensaios de regeneração em ciclos mostraram que após seis (6) ciclos a eficiência de regeneração do sólido sorvente foi de 67,8% e a remoção de BPA obtida ao final desses ciclos foi de 60,9%. Quanto à caracterização do sorvente, as micrografias mostraram que o carvão ativado, antes e após os ciclos de sorção/regeneração (S/R), possui superfícies bastante irregulares, heterogêneas e desordenadas, com elevada porosidade. Ensaios realizados em planta piloto de adsorção mostraram a viabilidade técnica de aplicação do carvão ativado para remoção de bisfenol em processos contínuos, tendo sido possível obter as condições operacionais e a curva de ruptura do sistema. Os resultados indicaram que a adsorção em leito fixo apresentou melhores resultados nas seguintes condições: vazão de alimentação de 20 mL.min-1, concentração inicial de 100 mg.L-1 e 10g de sólido sorvente. / The bisphenol-A (BPA), a monomer used in the manufacture of epoxy resins and polycarbonate plastics is considered a powerful endocrine disrupter which causes various diseases. The objective of this work was to study the removal of BPA from aqueous solutions by adsorption technique in batch and continuous process. The regeneration capacity of sorbents used in batch tests was also investigated. For this purpose, different adsorbents were initially tested (zeolite powder and granular modified with chitosan, sodium zeolite and granular activated carbon) in order to determine which one presents higher removal rates of BPA. After that, sorption tests were carried out with the chosen solid aiming to find the best process conditions considering pH, residence time and sorbent concentration. Hence, equilibrium isotherms were constructed for this system. The fixed bed adsorption was evaluated through adsorption experiments using a pilot plant, according to the influence of three variables: the effect of the mass of the used adsorbent (10g and 5g), flow rate (15 mL.min-1 and 20 mL.min-1) and initial concentration (50 mg.L-1 and 100 mg.L-1). In activated carbon regeneration it was employed acetone, n-pentane and dichloromethane as solvents and the ultrasound technique was also used. The applied sorption conditions were the following: pH 6, time 60 min, sorbent concentration of 10 g.L-1 and BPA solution of 10 mg.L-1. The external microstructure and semi-quantitative elemental composition of the activated carbon before and after the sorption and regeneration were analyzed by SEM-EDS technique. Concerning sorption, the best results were found with granular activated carbon, reaching removal efficiency of 56.7% at pH 7. The sorption isotherm model that best fit the experimental data was the Sips model, which provided constant energy or affinity of the process and also the maximum accumulation of BPA in the sorbent. The regeneration tests showed that the best agents of regeneration were acetone (100%), with removal efficiency of 105.6% and the ultrasound technique, which presented a removal efficiency of 106.4% after a contact time of 30 min. Considering that the technique doesn’t generates waste, it was decided to use the ultrasound tests for regeneration cycles. The regeneration test time in ultrasound bath showed that for contact times of 30, 40, 50 and 60 min the regeneration was very similar. Thus, for testing cycles of sorption-regeneration, the used contact time was 30 minutes. The regeneration cycle tests showed that after six (6) cycles of regeneration efficiency of the solid sorbent was 67.8% and the removal of BPA obtained at the end of these cycles was 60.9%. Regarding characterization of the sorbent, the micrographs showed that the activated carbon before and after cycles of sorption/regeneration (S/R), has very irregular, heterogeneous and disordered surfaces with high porosity. Tests carried out in a pilot plant adsorption showed the technical viability of application of the activated carbon for removal of bisphenol in continuous processes, thus it is possible to obtain operating conditions and the breakthrough curve for this system. These results indicate that the fixed bed adsorption presents best results in the following conditions: feed flow rate of 20 mL.min-1, initial concentration of 100 mg.L-1 and 10 g of solid sorbent.

>Magister Scientiae - MSc / The degradation of endocrine disrupting chemicals (EDCs) is a topic of high importance and one that research efforts are continually being focused on. These harmful chemicals are known to cause adverse health effects in humans and animals. In particular, bisphenol-A (BPA), a high volume chemical which is mainly used in the manufacturing of polycarbonate plastics and epoxy resins have been shown to be implicated in the development of a variety of health problems. In this study, the ability of two fungal laccases [Trametes versicolor (TvL) and Trametes pubescens (TpL)], and two bacterial laccases [Streptomyces coelicolor (SLAC), and a mutant of SLAC (SLAC- VN)] to degrade or remove BPA from solution was investigated. The commercial preparation of TvL was used for the purposes of this study, while TpL was produced from the native strain. T. pubescens was cultured in shake-flasks, the supernatant harvested and subjected to ammonium sulphate precipitation. SLAC and SLAC-VN were produced from recombinant strains using a standard protocol and the enzymes purified by size-exclusion chromatography. The presence of the laccases were confirmed by the 2,6-dimethoxyphenol assay and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE).The removal or degradation of BPA from solution was determined for the free enzymes, as well as the enzymes in immobilised form. For immobilisation, the enzymes were encapsulated in sodium alginate beads and cross-linked to form cross- linked enzyme aggregates (CLEAs).High levels of BPA removal was exhibited by the fungal laccase, TpL (100% removal)and the bacterial mutant laccase, SLAC-VN (96%) in their free form. When all four laccases were encapsulated in sodium alginate beads, a number of changes to the characteristics of the enzymes were observed. Overall, the level of BPA removal was reduced for all enzymes as when compared to the free laccases, while SLAC-VN removed more BPA than either of the fungal laccases (59% for SLAC-VN versus 57% TvL and 54% for TpL). The encapsulation of the laccases in alginate beads also led to changes in the optimal temperature for BPA removal, with all encapsulated laccase being able to remove BPA optimally at 40°C. The immobilisation of the laccases in CLEA form had the most significant effect on the BPA removal ability of the laccases. The pH range for both fungal laccases was extended beyond the acidic range [for TpL, optimal removal occurred at pH 8.5 compared to pH 4.5 (free) and pH 6.0 (encapsulated)]. Most remarkable, however, was that the formation of CLEAs greatly enhanced the BPA removal ability of SLAC (60% removal compared to 25% when encapsulated).