Reúso de águas residuárias tratadas: inovação tecnológica e aceitabilidade social

Treated wastewater can be applied in many activities, however, depending on the required use, the quality level may not be achieved using conventional processes. This work analyzed the performance of the Water Phase Reform in the treatment of sanitary sewage, with and without the presence of emerging pollutants, aiming at the reuse of liquid effluents for potable and non- potable purposes, and evaluated the social acceptability regarding the practice of reuse. Experiments were carried out in batch reactors, using synthetic wastewater and Pt-based catalysts, supported on two types of carbon materials: KETJENBLACK (KJB) and ENSACO. The analysis of social acceptability to the reuse of treated wastewater had as main research instruments the questionnaire and semi-structured interviews, carried out with renowned experts in the sanitation sector. The average efficiency of the TOC removal process was 62.05% in tests with ENSACO carbon material and without the active metal, and 88.19% with KJB. For the COD parameter, the mean removal percentages were 57.57% and 63.48% in assays with ENSACO and KJB support, respectively. The process achieved an average efficiency in the reduction of total nitrogen of 34.63% in the analyzes with ENSACO carbon and 54.39% with KJB. In samples with emerging compounds, the Aqueous Phase Reform proved to be effective both in tests containing only the carbon material ESSACO and without platinum, and with Pt/ENSACO catalyst, with average removal percentages in the tests with ESSACO of 98.34% for caffeine, 99.55% for carbamazepine, 100% for diclofenac and 96.58% for ibuprofen. Gas production was higher in reactions with Pt/ENSACO catalyst, with average values of 19.20% for H2 and 11.70% for CH4. As for meeting the quality standards for reuse water, it was found that despite the vast majority of regulations and guidelines evaluated do not establish maximum values allowed for quality parameters, the Water Phase Reform is a promising technique for the treatment of sanitary sewage, with effective elimination of the emerging contaminants evaluated. As for the acceptability of the population to the practice of reuse, there was high public acceptance for applications with reduced human contact and low acceptability for uses involving direct consumption. However, even with all the cultural barriers, 84.6% of the participants were in favor of using reuse water from a new sewage treatment technique.A água residuária tratada pode ser aplicada em muitas atividades, entretanto, dependendo do uso requerido, o nível de qualidade pode não ser alcançado com a utilização de processos convencionais. Este trabalho analisou o desempenho da Reforma em Fase Aquosa no tratamento de esgotos sanitários, com e sem a presença de poluentes emergentes, visando o reúso dos efluentes líquidos para fins potáveis e não potáveis, e avaliou a aceitabilidade social quanto à prática de reúso. Foram realizados experimentos em reatores de batelada, empregando- se água residuária sintética e catalisadores a base de Pt, suportados em dois tipos de materiais carbono: KETJENBLACK (KJB) e ENSACO. A análise de aceitabilidade social ao reúso de águas residuárias tratadas teve como principais instrumentos de pesquisa o questionário e entrevistas semiestruturadas, realizadas com renomados especialistas do setor de saneamento. A eficiência média do processo na remoção de COT foi de 62,05% nos testes com material carbono ENSACO e sem o metal ativo, de 88,19% com KJB. Para o parâmetro DQO, os percentuais médios de remoção foram de 57,57% e de 63,48% nos ensaios com suporte ENSACO e KJB, respectivamente. O processo alcançou eficiência média na redução do nitrogênio total de 34,63% nas análises com o carbono ENSACO e de 54,39% com KJB. Nas amostras com compostos emergentes, a Reforma em Fase Aquosa mostrou-se eficaz tanto nos ensaios contendo apenas o material carbono ENSACO e sem a platina, quanto com catalisador Pt/ENSACO, com percentuais médios remoção nos testes com ENSACO de 98,34% para a cafeína, 99,55% para a carbamazepina, 100% para o diclofenaco e 96,58% para o ibuprofeno. A produção de gás foi maior nas reações com catalisador Pt/ENSACO, com valores médios de 19,20% para o H2 e de 11,70% para o CH4. Quanto ao atendimento aos padrões de qualidade para águas de reúso, constatou-se, que apesar da grande maioria dos regulamentos e diretrizes avaliados não estabelecerem valores máximos permitidos para os parâmetros de qualidade, a Reforma em Fase Aquosa é uma técnica promissora para o tratamento de esgoto sanitário, com efetiva eliminação dos contaminantes emergentes avaliados. Quanto a aceitabilidade da população à prática de reúso, observou-se alta aceitação pública para aplicações com reduzido contato humano e baixa aceitabilidade para os usos que envolvem consumo direto. Contudo, mesmo com todos os entraves culturais, 84,6% dos participantes se colocaram a favor de utilizar água de reúso proveniente de uma nova técnica de tratamento de esgot

Reuse of effluents from cattle slaughterhouses: multicriteria evaluation

Cattle slaughterhouses generate a large amount of effluent with a high concentration of organic and inorganic compounds. However, the choice of appropriate technologies can produce effluents with sufficient quality for the practice of reuse as a strategy for saving water. This study aimed to determine the efficiency of effluent treatment systems from cattle slaughterhouses to promote the reuse of effluents, specifically for fertigation. The multicriteria analysis was employed, adopting the ELECTRE I method. The effluent treatment alternatives, the definition of the degree of importance, and the weights of each established criterion were considered. The estimated volume of effluents generated in slaughterhouses in Brazil was 85.374 million m³/year, with a high concentration of biochemical/chemical oxygen demand, nutrients, oils, and greases, solids, and E. coli. The treatment technologies that showed the best performance were UASB reactor + ultrafiltration and activated sludge + ultrafiltration, producing effluents with compatible quality for agricultural reuse under Brazilian legislation