Dissertations / Theses on the topic 'Industrial leachates'

Three major microbial subpopulations from an industrial leachate system were characterized with respect to their bioremediation potential, and particular aspects of a cometabolically active subpopulation were determined.

As indústrias lançam diversos poluentes no meio ambiente. Dentre os poluentes destacam-se os elementos tóxicos presentes em efluentes líquidos por acarretarem alto risco potencial à saúde humana e ao meio ambiente. Os efluentes podem ser tratados por materiais adsorventes, os quais podem ser provindos de resíduos industriais. Uma forma de contribuir significativamente na sustentabilidade de uma indústria é a transformação de um de seus resíduos em sub-produto de valor agregado para aplicação no tratamento de seus efluentes líquidos como adsorvente de baixo custo. O objetivo deste trabalho foi sintetizar, e caracterizar zeólitas de cinzas de carvão e avaliar sua aplicação como material adsorvente no tratamento de efluente. Os materiais zeolíticos derivados de três tipos diferentes de cinzas de carvão (cinzas manga, cinzas ciclone e cinzas pesadas) geradas na usina termelétrica de Figueira-PR foram usados para tratar o lixiviado do aterro de cinzas de carvão da mesma usina. As seguintes características das zeólitas foram determinadas: composição mineralógica, composição química, teor de carbono total, análise morfológica, área superficial específica, capacidade de troca catiônica (CTC), perda ao fogo, pH, condutividade e densidade aparente. A fase zeolítica formada foi do tipo sodalita com as três amostras usadas como matéria prima após ativação hidrotérmica alcalina. O material zeolítico de cinzas manga apresentou a menor relação SiO2/Al2O3 (1,46), maior CTC (2,36 meq g-1) e área superficial específica (69,5 m2 g-1) e, consequentemente, maior capacidade de remoção dos íons do efluente. As concentrações de As e Cr estavam acima do padrão de lançamento de efluentes. As três amostras de materiais zeolíticos apresentaram uma remoção significativa de Ni, Cd, Zn e Co na dose de 10 g.L-1. Os materiais zeolíticos das cinzas manga e ciclone foram eficientes para reduzir a concentração de As abaixo do limite imposto pela legislação, enquanto a remoção do Cr não foi efetiva com nenhum dos materiais. Na segunda etapa do trabalho, as zeólitas foram modificadas com o surfactante brometo de hexadeciltrimetilamônio (HTDMA-Br) em concentrações de 1,8 e 20 mmol L-1. A modificação das zeólitas não melhorou a eficiência de remoção do As. A remoção do Cr usando a amostra de zeólita de cinzas manga modificada com HDTMA-Br 20 mmol L-1 resultou em uma concentração final muito próxima ao limite permitido pela legislação.
The industries release various types of pollutants into to the environment. Among these pollutants are the liquid effluents containing toxic elements, they carry a high potential risk to human health and the environment. Some effluents can be treated by adsorbent materials, which can be made from industrial waste. One way to contribute significantly to the sustainability of an industry is to transform one of its residues into a value-added by-product and use in the treatment of its own liquid effluents as a low cost adsorbent. The objective of this estudy was to synthesize and characterize coal ash zeolites and evaluate their application as adsorbent material in the treatment of effluent. Zeolite materials derived from three different types of coal ash (fly ashes, cyclone ashes and heavy ashes) generated at the Figueira-PR thermoelectric plant were used to treat leachate from the coal ash landfill of the same plant. The following zeolite characteristics were determined: mineralogical composition, chemical composition, total carbon content, morphological analysis, specific surface area, cation exchange capacity (CTC), fire loss, pH, conductivity and bulk density. The zeolite phase formed with the three samples used as raw material after alkaline hydrothermal activation was sodalite. The zeolite material from fly ash had the lowest SiO2/Al2O3 ratio (1.46), higher CTC (2.36 meq g-1) and specific surface area (69.5 m2 g-1) and, consequently, greater effluent removal capacity. The As and Cr concentrations were above the effluent discharge standard. The three samples of zeolitic materials showed a significant removal of Ni, Cd, Zn and Co in the dose of 10 g L-1. The zeolite materials from fly and cyclone ash were efficient to reduce As concentrations below the limit imposed by legislation, while removal of Cr was not effective with any of the materials. In the second stage of the study, the zeolites were modified with the surfactant hexadecyltrimethylammonium bromide (HTDMA-Br) in concentrations of 1.8 and 20 mmol.L-1. The zeolite removal efficiency of As did not improve after its modification. Removal of Cr using the 20 mmol.L-1 modified HDTMA-Br modified fly ash zeolite sample resulted in a final concentration very close to the limit allowed by the legislation.

A decomposição dos resíduos sólidos dispostos em aterro sanitário produz um líquido denominado chorume, o qual apresenta altos teores de poluentes. A caracterização do chorume do aterro sanitário de Cachoeira Paulista-SP, conforme os parâmetros de descarte, comprovam a presença de contaminantes tais como DQO (3596 mg L-1), COT (1773 mg L-1), nitrogênio amoniacal (1496 mg L-1), nitrogênio orgânico (49 mg L-1) e fenol (162 mg L-1). Após aprovada a Política Nacional de Resíduos Sólidos, a legislação aumenta a fiscalização e o controle da disposição e destinação adequada de resíduos sólidos urbanos e, desta forma, a sociedade moderna passou a necessitar de processos capazes de tratar tal lixiviado. As indústrias metalúrgicas, ao executarem técnicas de proteção de superfícies metálicas, produzem um rejeito industrial denominado de borra de fosfato. Nesta perspectiva, este trabalho visou o reuso deste rejeito devido à presença de metais de transição (catalisador na ozonização catalítica) e de fosfato (reagente de precipitação de amônia) para o processo de degradação do chorume. O objetivo desse reagente residual é proporcionar uma redução no custo do processo de tratamento, aplicar uma destinação para tal rejeito e ainda, talvez, reduzir a toxicidade do chorume para o devido descarte ou pré-tratamento. O experimento com 60 minutos, pH 2,5, 90 g L-1 de borra in natura e 3 L de chorume obteve redução de 15,41% de DQO. O mesmo experimento, exceto o fosfato, usando reagentes de sulfato de ferro, zinco e manganês obteve 57,5% de DQO. Isso comprovou o efeito negativo do íon fosfato, pelo sequestro de radical hidroxila, na ozonização catalítica em média de 40% na redução de DQO. Uma metodologia foi desenvolvida para separar o fosfato dos demais íons metálicos, através de dois processos (ácido sulfúrico e ácido clorídrico) para obter dois produtos (borra em pó com a presença dos metais de interesse e solução alcalina concentrada de fosfato). A ozonização catalítica da borra em pó foi avaliada em planejamento fatorial 23 com ponto central, cuja maior degradação foi em 90 minutos e pH 4, quando realizada com borra em pó sulfúrica (4,2 g L-1) obteve uma redução média de 59,09% COT (R$ 0,101 por litro) e com borra em pó clorídrica (4,75 g L-1) de 65,52% COT (R$ 0,100 por litro). Nestes tratados, um fatorial 22 com ponto central, foi usado na avaliação de precipitação da estruvita, o qual comprovou-se que a remoção de amônia é melhor em pH 12, diferente da literatura (pH 9,5), e quando executadas com prévio tratamento físico-químico (remoção dos catalisadores da ozonização), devido a menor interação no meio reacional. Nestas condições, com solução alcalina de fosfato (sulfúrica) em 20 minutos obteve redução de 96,74% de N-NH3 (R$ 0,365 por litro) e com solução alcalina de fosfato (clorídrica) em 10 minutos uma redução de 94,71% de N-NH3 (R$ 0,305 por litro). Isso demonstra o uso potencial desse rejeito no tratamento de chorume, ao tratar dois passivos ambientais e minimizar impactos ambientais antropogênicos, além da possível aplicação produção de fertilizante.
The decomposition of solid waste present in landfill produces the landfill leachate, which has high levels of pollutants. The characterization of the landfill leachate from Cachoeira Paulista - SP, according the discard parameters, proves the presence of contaminants due to high level of COD (3596 mg L-1), TOC (1773 mg L-1), ammonia nitrogen (1496 mg L-1), organic nitrogen (49 mg L-1) and phenol (162 mg L-1). After National Solid Waste Policy approval, the legislation increases the supervision and control of the proper disposal of solid waste, so the modern society began to require processes able to treat such leachate. Metallurgical industries do the metal surfaces protection techniques and produce an industrial waste of phosphate sludge. In this perspective, the aim of this study comprehends the reuse of metallurgical waste due to the presence of transition metals (catalyzer in ozonation) and phosphate (ammonia precipitation reagent) for the degradation process. The objective of this residual reagent is induce a reduction in the cost of the treatment process, apply a proper disposal for metallurgical waste and, perhaps, reduce the toxicity of landfill leachate to discard or pre-treatment. The experiment with 60 minutes, pH 2.5, 90 g L-1 sludge waste in natura and 3 L of landfill leachate obtained 15.41% reduction in COD. The same experiment, except the phosphate, using iron, zinc and manganese sulfate reagents reached 57.5% of the COD. This proved the negative effect of phosphate ion, the scavenger of hydroxyl radical in the catalytic ozonation around 40% reduction of COD. A method had been developed to separate phosphate from other metal ions, through two processes (hydrochloric acid and sulfuric acid) to obtain two products (phosphate sludge powder with metals of interest and phosphate concentrated alkaline solution). The catalytic ozonation of sludge powder was evaluated in 23 factorial design with central point, and the better degradation was obtained in 90 minutes and pH 4, when performed with sludge powder sulfuric (4.2 g L-1) had an average reduction of 59.09% TOC (R$ 0,101 per liter) and with sludge powder hydrochloric (4.75 g L-1) 65.52% TOC (R$ 0,100 per liter). In landfill leachate treated, a 22 factorial design with center point was used in the precipitation evaluation of struvite, which proved that the ammonia removal is better at pH 12, different from the literature (pH 9.5), and when performed after to physico-chemical treatment (removal of catalyzer of ozonation) due to the less interaction in the reaction. In these adjust conditions, with phosphate alkaline solution (sulfuric) was obtained in 20 minutes 96.74% of reduction of N-NH3 (R$ 0,365 per liter) and phosphate alkaline solution (hydrochloric) in 10 minutes a decrease of 94.71% N-NH3 (R$ 0,305 per liter). This result demonstrates the potential use of this waste in the treatment of landfill leachate, treat two contaminants and minimize anthropogenic environmental impacts, as well as possible application of struvite on fertilizer production.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
Avaliou-se o uso de testes de ecotoxicidade com o organismo-teste Daphnia magna no biomonitoramento de efluentes de ETEs industriais (real e sintÃtico), hospitalares e de aterro sanitÃrio. Para tanto, foram selecionadas algumas ETEs a citar: Industrial Real (Sistema Integrado do Distrito Industrial â SIDI), Industrial SintÃtico (Reator anaerÃbio seguido dos pÃs-tratamentos em Reator em Batelada SeqÃencial â RBS e Processo de OxidaÃÃo AvanÃado â POA do tipo H2O2/UV, tratando um efluente contendo o corante azo Reactive Black 5 - RB5), Hospitalar (Hospital Geral Waldemar de AlcÃntara â HGWA) e Aterro SanitÃrio (Lixiviado coletado na saÃda do sistema de lagoas de estabilizaÃÃo do Aterro SanitÃrio Metropolitano Oeste de Caucaia â ASMOC e submetido a um pÃs-tratamento por meio de um Reator Aerado Submerso â RAS). Os testes de toxicidade aguda realizados com o lixiviado indicaram que o efluente ao sistema ASMOC apresentou CE50 de 68%, o qual podia ser classificado como moderadamente tÃxico. Assim, alÃm de alguns parÃmetros fÃsico-quÃmicos nÃo estarem atendendo à Portaria n 154/02 da SEMACE, os resultados ecotoxicolÃgicos confirmaram o potencial poluidor do lixiviado em questÃo para ser descartado no Riacho Garoto, de baixa capacidade de diluiÃÃo. O pÃs-tratamento aerÃbio realizado no RAS contribuiu bastante na reduÃÃo da toxicidade do lixiviado, tanto em termos fÃsico-quÃmicos quanto em termos ecotoxicolÃgicos, aumentando o valor de CE50 para 95,04%, se configurando como uma boa opÃÃo de pÃs-tratamento. Os resultados obtidos com o esgoto afluente e efluente ao SIDI revelaram que o CE50 passou de 18,05% para 61,90%, mudando a classificaÃÃo de muito tÃxico para moderadamente tÃxico, respectivamente. Entretanto, o estudo efluente do SIDI, com as caracterÃsticas fÃsico-quÃmicas e de toxicidade encontradas, associadas à elevada vazÃo de esgotos tratados, representam um sistema com uma carga poluidora que merece ser investigada no corpo receptor. Em relaÃÃo ao esgoto hospitalar, observou-se que o esgoto bruto apresentou alta toxicidade e um CE50 de 7,27% (muito tÃxico) enquanto que o efluente tratado pela seqÃÃncia de reator UASB e lodo ativado apresentou CE50 de 30,83% (tÃxico). Portanto, os ensaios ecotoxicolÃgicos apontaram para o carÃter tÃxico do efluente em termos agudos, e podemos inferir a toxicidade crÃnica que tal efluente pode causar no corpo hÃdrico, jà que o mesmo pode conter elevadas concentraÃÃes de fÃrmacos, hormÃnios e outros micro-poluentes. O efluente sintÃtico bruto contendo o corante RB5 apresentou CE50 de 23,02%, sendo classificado como efluente muito tÃxico. ApÃs o tratamento no reator UASB, o valor de CE50 caiu para 40,34%, ou seja, houve uma diminuiÃÃo da toxicidade no tratamento anaerÃbio. No pÃs-tratamento pelo RBS ocorreu uma diminuiÃÃo significativa de toxicidade, em que o mesmo pode ser classificado como nÃo tÃxico. Entretanto, o POA do tipo do tipo UV/H2O2 provocou aumento da toxicidade, com o efluente apresentando CE50 de 20,17%, recebendo classificaÃÃo de muito tÃxico. A investigaÃÃo ecotoxicolÃgica em D. magna para avaliar o efeito da concentraÃÃo de H2O2 revelou elevada toxicidade do residual de perÃxido, sendo que em todas as diluiÃÃes testadas houve morte de 100% dos organismos expostos. Portanto, os estudos indicaram que muito embora o processo de oxidaÃÃo avanÃado (POA) do tipo H2O2/UV tenha uma boa perspectiva de aplicaÃÃo no tratamento de esgotos recalcitrantes, o perÃxido residual tem que ser cuidadosamente monitorado, nÃo sà por elevar a DQO do efluente como tambÃm por aumentar a toxicidade deste. Como conclusÃo geral da presente dissertaÃÃo foi possÃvel demonstrar a grande importÃncia dos testes ecotoxicolÃgicos agudos e crÃnicos no biomonitoramento de cargas poluidoras localizadas em corpos de Ãgua do CearÃ, assim como para um melhor entendimento dos processos biolÃgicos e nÃo biolÃgicos de tratamento de esgotos.
We evaluated the use of ecotoxicity tests with Daphnia magna for the biomonitoring of industrial effluents (real and synthetic), hospital effluent and leachate: real industrial wastewater (Integrated System of Industrial District - SIDI), synthetic industrial wastewater (anaerobic reactor followed by the post-treatments Sequential Batch Reactor - SBR and Advanced Oxidation Process - AOP type H2O2/UV, both treating a wastewater containing the azo dye Reactive Black 5 - RB5), Hospital effluent (Hospital Geral Waldemar de AlcÃntara - HGWA) and Leachate collected at the output of the stabilization ponds system located at the Metropolitan Sanitary Landfill West of Caucaia - ASMOC and submit to the post-treatment of Submerged Aerated Reactor - SAR. The acute toxicity tests conducted with the leachate indicated that the effluent from ASMOC system showed EC50 of 68%, which could be classified as moderately toxic. Thus, in addition to some physical and chemical parameters that are not complying with the limits defined in the Portaria nÂ. 154/02 of SEMACE, ecotoxicological results confirm the pollution potential of the leachate to be discharged at the Riacho Garoto, which has low dilution capacity. The post-aerobic treatment performed in SAR showed to greatly contribute in reducing the leachate toxicity in terms of physical-chemical and ecotoxicological characteristics, increasing the EC50 value to 95.04%, and showing to be a good post-treatment option. The results obtained with the real industrial influent and effluent from SIDI revealed that the EC50 increased from 18.05% to 61.90%, switching the classification from very toxic to moderately toxic, respectively. However, the SIDI effluent, considering the physico-chemical properties and toxicity found, associated with the high flow rate of treated wastewater, represents a system with a pollutant load that should be further investigated in the receiving water body. Regarding the hospital wastewater, it was observed that the raw wastewater had a high toxicity, with EC50 of 7.27% (very toxic), while the effluent treated by the sequence of UASB and activated sludge showed EC50 of 30.83% (toxic). Therefore, ecotoxicological tests revealed the toxic character of the effluent in terms of in acute toxicity and it can infer the chronic toxicity that such an effluent can cause in the water body, since it may contain high concentrations of drugs, hormones and other micro-pollutants. The synthetic wastewater containing the azo dye RB5 presented EC50 of 23.02%, classified as very toxic. After treatment in the UASB reactor, the EC50 value increased to 40.34%, i.e. there was a toxicity decrease by the anaerobic treatment. In the post-treatment by SBR, a significant reduction of toxicity was found and the effluent could be classified as non-toxic. However, the UV/H2O2 AOP increased the toxicity, in other words the EC50 decreased to 20.17%, being classified as very toxic. The effect of H2O2 concentration on the ecotoxicological test with D. magna was assessed and showed high toxicity of the residual peroxide, in all dilutions tested, causing death of 100% of the exposed organisms. Therefore, the studies indicated that although the H2O2/UV advanced oxidation process (AOP) has a good prospect for application on recalcitrant compounds, the peroxide residual has to be carefully monitored, not only because it increases the wastewater COD but also because it increases the effluent toxicity. As a general conclusion of this research, it was possible to show the great importance of acute and chronic ecotoxicological tests for the biomonitoring of pollution sources located in CearÃ, and also for a better understanding of biological and non-biological processes applied to wastewater treatment.

L’industrie produit de grandes quantités d’effluents aqueux qu’il convient de traiter. Des traitements alternatifs aux procédés biologiques doivent être développés pour certains effluents toxiques et/ou non biodégradables. L’oxydation en voie humide catalytique repose sur l’action de l’oxygène sur les polluants en phase aqueuse à haute température et haute pression. Préalablement à cette étude, des catalyseurs au Ru ou Pt supportés sur ZrO2 ou TiO2très actifs et très stables pour l’OVHC de polluants modèles et de quelques effluents réels ont été développés. Ce travail a examiné ces catalyseurs sur d’autres effluents réels : un effluent provenant d’une unité de production de membranes contenant du glycérol et du DMF, uneffluent de sauce de couchage provenant de l’industrie papetière et un concentrât de lixiviatde décharge. Les catalyseurs se sont révélés très actifs et stables pour la minéralisation du glycérol, mais une forte lixiviation a été observée lors de l’OVHC du DMF du fait de la présence d’amines. L’oxydation de l’effluent de sauce de couchage permet de minéraliser la charge organique, facilitant le recyclage de la charge minérale, avec une amélioration accrue de la biodégradabilité du surnageant en présence des catalyseurs. Enfin, l’ajout de catalyseurs lors de l’OVH du concentrât de lixiviat de décharge permet d’améliorer sa minéralisation et d’éliminer totalement les ions ammonium
Industries produce huge volumes of effluents which need to be treated before disposal.Alternative treatments to the more classical biological techniques are required in the case oftoxic and/or non biodegradable effluents. The wet air oxidation (WAO) and catalytic wet airoxidation (CWAO) are based on the reaction of an oxidant (oxygen) with the pollutants in aqueous phase at high temperature and pressure. Ru or Pt catalysts supported on zirconium and titanium oxides were previously shown to be highly active and stable in the CWAO of awide range of model compounds and real complex effluents. These catalysts were evaluated in the CWAO of problematic effluents: one containing glycerol and DMF, one paper coatingslip effluent and one concentrated landfill leachate. The catalysts showed high activity and stability in the CWAO of glycerol, while the metal leached upon DMF CWAO due to the presence of amines. WAO leads to the partial mineralization of the organic load in paper coating slip, allowing an easy separation recycling of mineral pigments, with an improved biodegradability of the supernatant with the use of a catalyst. The use of a catalyst upon landfill leachate WAO leads higher COT conversion and complete ammonia elimination

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This work aims to remove efficiently organic and inorganic pollutants from a municipal sanitary landfill leachate effluent (SLLE) through of the integrated purification treatment application, composed by the electrocoagulation (ECP) and biological oxidation processes (BOP), looking for the drastic drop on the toxicity. In the first treatment phase, an ECP-based reactor was constructed consisting in a series of 6 aluminum electrode, providing an effective area of 350 cm2 and a useful volume of 1,0 L. In the framework of the response surface methodology (RSM), a 3³ complete factorial experimental design (CFED) at three levels of the three ECP important parameters: initial pH, electric current density (ECD) and electrolysis time (ET) was regarded. A set of responses related to the ECP treatment, such as, the reduction of color, turbidity, COD and iron concentration, was interpreted within the RSM. Additionally, the Analysis of Variance (ANOVA was applied to assess the quality of the second-order polynomial mathematical models that were adjusted to the CFED data. Keeping fixed the best ECP condition (pH and ECD) for the pollutant removals, a set of kinetic tests was carried out regarding a wide range of ET values. The toxicity of ECP treated samples was assessed by the application of bioassays based on the mortality level of the brine shrimp (Artemia salina) and the germination of Lactuca sativa seeds. The toxicity level was assessed by a statistical estimation of the median lethal concentration (LC50) through the application of bioassays with Artemia salina and Lactuca sativa. The biodegradability index by applying the Zahn Wellens test was also assessed. Keeping fixed the ECP condition for which was obtained the lowest toxicity and the highest biodegradability index, the second phase of treatment by BOP was performed. In this regard, a biological reactor with a useful volume of 3.5 L was adjusted to operate keeping fixed the condition of pH 7, temperature of 33 oC and dissolved oxygen of 50%. A relation food/microorganism of one was considered. After that, the residual ammonia in samples was completely removed applying the stripping method (air injection of 50 Lh-1). From the CFED data related to the first treatment phase, the best ECP condition was found by setting the pH at 5, ET at 120 min and ECD at 128.57 Am-2 for which was obtained the maximum removal of 99, 98, 68 e 99% for color, turbidity, COD and iron concentration, respectively. From the kinetic tests, it was possible to verify that the application of the ECP has actually reduced the SLLE toxicity being an ET of 5 min enough to achieve the minimum time required to obtain the lowest toxicity index (LC50 of 43%) that was found in both biotests. The highest biodegradability index was found when an ET value of 45 min. was regarded. The second POB treatment has showed a significant performance on removals of the organic parameters, with values of 95% and 89% for COD and DOC, respectively. Because of achieving an almost 100% removal of the ammoniacal nitrogen, the main result was the substantial improvement on the LC50 value about of 95%, as suggested by the A. salina biotest. Thus, although there were small amounts of pollutants after both treatments (PEC and POB), an almost total toxicity depletion.
Este trabalho, tem como objetivo remover eficientemente os poluentes orgânicos e inorgânicos de efluente de lixiviado proveniente de aterro sanitário municipal mediante a aplicação do tratamento de purificação integrado composto pelos Processos de Eletrocoagulação (PEC) e Oxidação Biológica (POB), visando especificamente a queda da toxicidade e o cumprimento da condição ambientalmente segura para o descarte final em corpos hídricos. Para o PEC, construiu-se um reator com 6 eletrodos de alumínio, tendo uma área efetiva de 350 cm2 e um volume efetivo de efluente de 1,0 L. No contexto da Metodologia de Superfícies de Resposta (MSR), foi proposto um planejamento experimental 3³, variando-se três parâmetros importante do PEC: pH inicial, Densidade de Corrente Elétrica (DCE) e Tempo de Eletrólise (TE). As respostas ao tratamento por PEC (cor, turbidez, DQO e concentração de ferro) foram interpretadas dentro da MSR, verificando pela Análise de variância (ANOVA) a qualidade da representatividade dos modelos matemáticos, polinomiais de segunda ordem, ajustados aos dados. Mantendo fixa a melhor condição de remoção de poluentes pelo PEC quanto ao pH e DCE, experimentos cinéticos foram realizados considerando um amplo intervalo de TE. O nível de toxicidade foi inferido a partir da estimativa estatística da concentração letal mediana (CL50) mediante a aplicação de biotestes utilizando o microcrustáceo Artemia salina e sementes de Lactuca sativa. Avaliou-se o índice de biodegradabilidade, segundo o teste de Zahn Wellens. Na menor toxicidade e o maior índice de biodegradabilidade do lixiviado tratado pelo PEC foi realizada a aplicação da segunda fase de tratamento por POB. Para tanto, foi ajustado o reator biológico, com volume útil de 3,5 L a operar, de forma controlada, na condição de pH 7, temperatura de 33 oC e oxigênio dissolvido de 50%. Utilizou-se uma relação alimento/microrganismo igual a um. Após a realização da integração dos processos, foi feita a remoção de amônia residual do efluente pelo método de arraste (injeção de ar a 50 Lh-1). Da análise do planejamento da primeira fase de tratamento, encontrou-se a melhor condição do PEC no valor de pH igual a 5; TE em 120 min e DCE em 128,57 Am-2 cujo efeito foi a obtenção da máxima remoção de 99, 98, 68 e 99% na cor, turbidez, DQO e concentração de ferro, respectivamente. A partir dos testes cinéticos, foi possível verificar que o PEC reduziu consideravelmente a toxicidade, sendo o TE de 5 minutos a condição de menor toxicidade (CL50 de 43%) que foi encontrada por ambos os biotestes. O índice de biodegradabilidade do efluente de lixiviado tratado teve um aumento de aproximadamente 20% em relação ao efluente bruto para todos os tempos de tratamento por PEC; porém, o maior índice de biodegradabilidade foi encontrado quando houve um TE de 45 minutos. O segundo tratamento por POB apresentou expressiva remoção dos parâmetros orgânicos, sendo obtidas remoções de 95% e 89% para a DQO e o COD, respectivamente. Após a aplicação do processo de arraste de amônia, uma remoção de quase 100% do nitrogênio amoniacal foi alcançada, obtendo uma a CL50 da ordem de 95%, como revelada pelo bioteste com A. salina. Portanto, embora houvesse quantidades pequenas de poluentes após ambos os tratamentos (PEC e POB), atingiu-se a quase total depleção da toxicidade.

碩士
國立屏東科技大學
環境工程與科學系
92
Abstract This study investigates the leachate from an inorganic and uncombustible industrial waste landfill in the southern Taiwan. The leachate was treated with neutralization, coagulation and sedimentation processes before discharged. This study was focus on the colorization behavior of the leachate after a irradiation to sun. Leachate samples were collected and irradiate to UV, solar, and incandescent lamp to 1-336 hours, and sampling time was 24 hours pre one sample. Experimental results indicated that the control leachate samples(without irradiate)had a maximum adsorption peak at 295 nm. Fluorescent spectrum results indicated that the maximum excitation and emission wavelengths were at 295 and 425nm,respectively. The colority of leachates decreases as increasing light irradiate. Analysises of UV/VIS, fluorescent spectrum, and FT-IR, have resulted that the colorization of leachate might be induced by the de-HX reaction of fulvic acids in the leachate after lighting of solar.

Deals with the preparation, characterisation and testing of a series of new and improved synthetic anion exchange resins for selective absorption of the precious metals gold and silver, over the base metals, iron, copper, cobalt, zinc, nickel and aluminium, from an industrial leach solution.. The major method employed by industry, over the last thirty years, to abstract gold from low grade ore or tailings has been cyanide leaching followed by activated carbon concentration. The inherent problems with carbon prompted investigations into alternative methods for the concentration and abstraction of the metal cyano complexes. Ion exchange resins were employed for this purpose due to their versatility towards derivatisation and inertness to chemical and physical attack. The aims of this study were three-fold. The first aim was to design, synthesise and characterise a series of precious metal selective, strong and mixed base, anion exchange resins, where the cationic active site of each is sterically hindered to the approach of the base metal complexes. This aim also included development of the synthetic procedure to yield a resin with the highest degree of substitution possible. The second aim involved the synthesis of each resin on a variety of solid supports, from Merrifield (gel) type resins with different percentage crosslinking to highly crosslinked macroreticular (macroporous) matrices, and comparison of the degree of substitution, precious metal selectivity, equilibrium loading and loading rate achieved with each. This would then allow the identification and use of the most suitable resin base for this study. The final objective of this research involved an investigation into the performance of each resin employing both synthetic and industrial metal cyanide solutions. These investigations were performed under varying chemical and physical conditions (pH, temperature and concentration, etc.) and various kinetic models applied to each resin to mimic its loading characteristics. The selectivity and loading properties of the prepared resins were compared to those of commercial anion exchange resins, industrial activated carbon and other specific gold selective resins. Twenty-four resins were prepared by attaching tertiary amines to blank, chloromethylated poly-styrene/divinylbenzene copolymer resin matrices via seven day reactions in DMF at temperatures of 110°C, thus forming the strong base, quaternary ammonium anion exchanging active site. If required, the resins were then further functionalised to form the respective gold selective species. The degrees of substitution for the novel resins ranged from 0.2 meq/g to 2.5 meq/g depending upon the nature of the starting amine. As some resins are mixed base anion exchange, having one strong base site and one or more (up to four) weak/moderate base sites, gold loadings were obtained in the range 40 000 g Au/ton resin to 1 110 000 g Au/ton resin, or 4 % Au w/w to 110 % Au w/w. No obvious differences in substitution were noted between the different resin matrices trialed. The structure of these function-alised groups on the synthesised resins were characterised by microanalysis, difference infra-red and solid state nuclear magnetic resonance spectroscopy, atomic absorption spectrophotometry, and by comparison with model compounds. Similarities between the NMR spectral properties of the resins and model compounds as well as differences in these properties between the unattached amines and the resins were sought and inferences made as to the success of either the attachment or derivatisation reactions. Microanalysis and anion exchange were also employed to confirm the existence of each functionality and the type of novel resin formed. All the resins prepared show good to excellent selectivity for the precious metal cyano complexes, with four - NOTREN, TIPA, TIPAAPS and TEA-BE resins - displaying extra-ordinary discrimination at all pH values. The pH of the solution was observed to have no effect on the loading of strong base resins, however the equilibrium loading on the mixed base resins was limited by the acidity of the solution. Variation in solution temperature results in an almost linear increase in initial loading rate, indicating a first order process, with an average rate constant of 2 x 10-³sec-¹and activation energy of 55 kJ/mol. At 30 C the reactions were complete in about six hours, while at 80 C the resins were fully loaded in approximately 45 minutes. An increase in temperature also resulted in a linear decrease in equilibrium loading, indicating an exothermic process, with an average Hextraction of - 35 kJ/mol. Change in ionic strength of the solution resulted in a decrease in the final loading due to increased competition for the active site. Variation of resin matrix had little effect on the gold selectivity or loading of the respective resin. Each of the resins tested with the metal cyanide solutions (both synthetic and industrial) could be easily regenerated to their full capacity. The thiocyanate and thiourea elution procedures proved to be the most efficient for recovery of the precious metals with these selective resins. Rate constants of approximately 5 x 10-³sec-¹(first order process) for the thiourea method and 1.55 L/mol/sec (second order process) for the thiocyanate method were measured. The resins were recycled many times through loading, elution and regeneration cycles employing industrial leachate solutions for loading without any loss of selectivity or gold loading ability. There was also no evidence of the resins being poisoned by non-eluting metal cyano complexes during this trial. This reported research has thus led to the preparation of a series of resins which display a high selectivity for the precious metal cyano complexes while limiting the abstraction of the base metal cyano complexes. The performance of these resins compares favourably with that of other gold selective resins (some of which are being employed commercially as gold selective extractants ) and as a result show enormous potential to industry for use as selective auro- and argento-cyanide concentrators from cyanidation leachates.

Research Doctorate - Doctor of Philosophy (PhD)
Research presented in this thesis relates to the geo-remediation of spent potliner leachate contaminated groundwater, a designated hazardous liquid waste, using calcite and carbon dioxide and is presented as a “thesis by publication”. It is based on eight interrelated articles taken from four journal articles, three international conference abstracts, and a peer reviewed conference paper. In all publications the author has made a significant contribution to both the research, manuscript preparation and writing. Most of the research was funded by the Australian Research Council Linkage Grant LP100200488 in conjunction with Hydro Aluminium Kurri Kurri, New South Wales, Australia. This thesis presents an extensive geo-environmental site characterisation including groundwater monitoring, aquifer hydraulic, and cone penetration testing in order to determine the extent of contamination and geological conditions at the Hydro Aluminium field site. In conjunction with the field site characterisation, laboratory testing of over 300 batch kinetics experiments investigating the removal of the main contaminant, fluoride, as a function of various parameters including temperature, stirring rate, particle size, and CO₂ partial pressure and the associated kinetic modelling are presented. Of significance Chapter 6 presents the Hill model, a new model never before used in the field of geochemistry, to accurately describe the sigmodal kinetic reactions that occur in the remediation of spent potliner contaminated groundwater. The findings of the laboratory kinetics tests were used to determine cost effective remediation methods for the field site. Finally, the field and laboratory research are brought together in a detailed conceptual 3D model to investigate historical contaminant transport, and future permeable reactive barrier remediation options using visual modflow and MT3DMS.

Mestrado de dupla diplomação com o Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG)
This work aimed to prepare different adsorbent materials (bioadsorbent, pyrochar, hydrochar, and activated carbon), using olive stone and malt bagasse as feedstock and evaluating its performance and effectiveness in the adsorption of ammonia (NH3), deriving from composting leachate. A lab-scale adsorption system was assembled for the adsorption tests. The performance and effectiveness of the adsorbents on NH3 adsorption were evaluated objectively, by chemical analytical measurement, and subjectively by olfactometric assessment using the human sense of smell. The materials' preparation was studied to assess the biomass loss and the carbon released into the liquid phase during the hydrothermal carbonization process. Besides, resultant adsorbents were characterized to study their surface chemistry, elemental analysis, and textural properties. Saturated adsorbents were regenerated using water and subsequently re-used in the adsorption of NH3 coming from the leachate to assess their adsorption capacities after a sorptiondesorption cycle. The hydrochar derived from olive stone, prepared by hydrothermal carbonization assisted by sulfuric acid (H2SO4), was found as the best adsorbent for NH3 removal produced in this work since it has the lowest height of mass transfer zone (0.315 - 0.520 cm) and the highest NH3 adsorption capacity (9.445 - 11.421 mg g-1). The bioadsorbent prepared only by milling and drying olive stones was also capable of adsorbing NH3, showing a height of mass transfer zone of 0.484 - 0.565 cm, and an adsorption capacity of 0.975 - 1.455 mg g-1; besides the advantage of being environmentally-sound since it requires low energy expenditure, and no chemicals are used in its preparation. The olfactometric evaluations confirmed that the adsorbents mentioned above, prepared by olive stone, can reduce odor annoyance of the gases derived from leachate. Finally, the regeneration process using water delivered adsorbents capable of being used in one NH3 sorption-desorption cycle, with satisfactory performance (>70% of the mean NH3 adsorption capacity of its respective first-generation adsorbents), leading to increasing the materials' resource-use efficiency.
Este trabalho teve como objetivo preparar diferentes materiais adsorventes (bioadsorvente, pyrochar, hydrochar e carvão ativado), utilizando caroço de azeitona e bagaço de malte como matéria-prima e avaliar seu desempenho e eficácia na adsorção de amoníaco (NH3), proveniente do lixiviado de compostagem. Um sistema de adsorção em escala de laboratório foi montado para os testes de adsorção. O desempenho e eficácia dos adsorventes na adsorção de NH3 foram avaliados objetivamente, por medição analítica química, e subjetivamente, por avaliação olfatométrica usando o sentido do olfato humano. A preparação dos materiais foi estudada para avaliar a perda de biomassa e o carbono liberado na fase líquida durante o processo de carbonização hidrotermal. Além disso, os adsorventes resultantes foram caracterizados para estudar sua química de superfície, sua análise elementar e suas propriedades texturais. Adsorventes saturados foram regenerados com água e posteriormente reutilizados na adsorção de NH3 proveniente do lixiviado para avaliar sua capacidade de adsorção após um ciclo de sorçãodessorção. O hydrochar derivado de caroço de azeitona, preparado por carbonização hidrotermal assistida por ácido sulfúrico (H2SO4), foi apontado como o melhor adsorvente para remoção de NH3 produzido neste trabalho, por apresentar a menor altura de zona de transferência de massa (0,315 - 0,520 cm) e a maior capacidade de adsorção de NH3 (9,445 - 11,421 mg g-1). O bioadsorvente preparado apenas pela moagem e secagem do caroço da azeitona também foi capaz de adsorver NH3, apresentando uma altura de zona de transferência de massa de 0,484 - 0,565 cm e uma capacidade de adsorção de 0,975 - 1,455 mg g-1; além da vantagem de ser ambientalmente adequado, uma vez que requer baixo gasto de energia e nenhum produto químico é utilizado em sua preparação. As avaliações olfatométricas confirmaram que os adsorventes citados acima, preparados a partir de caroço de azeitona, podem reduzir a incomodidade do odor dos gases derivados do lixiviado. Por fim, o processo de regeneração com água forneceu adsorventes capazes de serem utilizados em um ciclo de sorção-dessorção de NH3, com desempenho satisfatório (> 70% da capacidade média de adsorção de NH3 de seus respectivos adsorventes de primeira geração), levando ao aumento da eficiência de utilização dos materiais.
I am grateful to the Foundation for Science and Technology (FCT Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020).