Chitosan in the treatment of mine spoil rainwater - An approach to protect the aquatic biota.

The mining industry suppresses vegetation, exposing large soil areas in its ordinary operation. Water pollution and turbidity are caused by the carrying of solids, mainly colloidal particles, to the watercourses due to the effect of rainfall events. Therefore, the discharge of those effluents will lead to failure with watercourse quality parameters. Thus, there is a need to treat drainages (rainwaters) from the mining industry. However, using common coagulants and flocculants can result in acute or chronic ecotoxicity for aquatic biota. In this scenario, this research aimed to evaluate using a natural coagulant, the biopolymer Chitosan, to remove turbidity from mining industry spoiled water through bio-coagulation. The ecotoxicity of the natural coagulant was compared to the commonly used coagulants. For this purpose, we used synthetic rainwater (SRW) from the dispersion of fine (colloidal) particles in natural waters. Materials (water and soil) were collected in the mining area's sumps (sedimentation basins). The turbidity of the produced SRW ranged from between 500 and 4000 NTU. Jar Tests using Chitosan (CTS), polyaluminum chloride (PAC®12), and Superfloc®N100 variable doses were carried out to compare the effects of the coagulating/flocculating agents on the SRW turbidity reduction. The obtained results demonstrated the efficiency of CHS on turbidity reduction. The results were encouraging for low turbidity samples (<1000 NTU), making it possible to meet the limit parameters recommended by the Brazilian legislation. In addition, it was possible to conclude both CHS and the effluents treated with this coagulant have lower toxicity to aquatic biota than the combination of PAC®12 and Superfloc®N100.

Proposal of a regulatory index of quality of water supply services-RIQS.

Among the challenges faced by regulatory authorities in the water sector, the large number of municipal supply services to be inspected and the cost of on-site inspections are prominent. To overcome these issues, decisions regarding the priority of inspections based on indicators is an alternative. Therefore, this research aims to propose and evaluate the Regulatory Index of Quality of Water Supply Service (RIQS) to triage on-site inspections of water supply systems in cities of the state of Minas Gerais. The study was conducted with information from the Regulatory Agency of Water Supply and Sanitation Services of Minas Gerais (Arsae-MG). The methodology followed seven steps: (i) selection of available indicators; (ii) grouping of indicators according to their typology; (iii) screening of indicators; (iv) establishment of standardized scale; (v) evaluation of the relative importance of typologies and indicators, through the adaptation of the analytic hierarchy process (AHP); (vi) determination of the RIQS; and (vii) analysis of results. As a result, we selected 12 indicators to compose the RIQS, which deal with efficiency, effectiveness, and customer relationship. We noticed that the indicator of water supply service coverage (17.2%) had the highest weight in the calculation of the RIQS, and the index of requests for an inspection of the water connection served on time (2.1%) had the lowest weight. In addition, 95.1% of the 591 municipalities evaluated presented excellent or good performance. Based on these results, we show that the RIQS can be used to identify cities with low performance and prioritize inspections in the most urgent water systems. Furthermore, these outcomes reveal the possibility of extending and adapting the methodology to other regulatory agencies around the world for identifying the priority of inspections in water supply systems at a municipal level.

Water security threats and challenges following the rupture of large tailings dams.

The rupture of mine-tailings dams can severely contaminate rivers, because released tailings can interact with water for years keeping contaminant concentrations high. The general purpose of this study was to examine the rupture of B1 tailings dam in Ferro-Carvão stream (municipality of Brumadinho, state of Minas Gerais, Brazil), which occurred in 25 January 2019 and contaminated the main water course (Paraopeba River) with 2.8 Mm3 of metal-rich tailings. The specific purpose was to assess the percentage of non-conforming concentrations following the event, considering the Normative Deliberation COPAM/CERH-MG no. 1. The results showed non-conforming aluminum, iron, manganese, lead, phosphorus and turbidity concentrations, clearly above pre-rupture averages, especially in the rainy period. The catastrophe triggered the suspension of Paraopeba River as drinking water source to the Metropolitan Region of Belo Horizonte (BHMR; 6 million people). Since then, the supply to the BHMR became an everyday challenge to water management authorities, because the Paraopeba source represented a 30% share. Mitigation measures are therefore urgently needed. As complementary objective to this study, we aimed to verify the possibility to restore drinking water supply through conventional treatment. The treatability of Paraopeba River water was assessed by the Raw Water Quality Index considering the rainy and dry periods in separate. The results suggested the possibility to lift up the suspension in the dry period, improving the regional water security. Considering the huge dataset on which this study is standing, our results are generalizable to similar events with sparser information.

Assessment of performance indicators for different sizes of water supply systems in Minas Gerais, Brazil.

Indicators are important tools to improve the efficiency of water supply systems. Considering that the performance could vary according to the systems' sizes, this research proposed financial, operational, and water quality indicators for water supply systems of municipalities with different populations in Minas Gerais, Brazil. The organisation and selection of the sample were based on available information in the National Sanitation Data System of 2014. We selected 363 municipalities of Minas Gerais and 56 predictors. Through multiple linear regression (MLR), we found that the commitment of revenues with expenditures and the ratio among revenues and expenses are the most relevant variables to describe the financial performance. Furthermore, water loss per connection and water-billing index were the most important to describe the operational performance. Finally, models related to water quality performance could not be established due to the low value of the coefficient of determination. We observed that supply systems have distinct variables to describe their financial and operational performance, according to their sizes. Small municipalities have a strong relationship with financial performance and expenses. Large counterparts have their performance related to the collection, which can be explained by the economy of scale. Considering the operational performance, we observed that larger municipalities have a strong relationship between their operational performance and water loss. These models are potential tools in the decision-making processes, which can be used to promote improvements in water supply systems.

Água de drenagem ou esgoto sanitário? Uma análise do sistema de macrodrenagem em cidade de médio porte na Região Nordeste / Drainage water or sanitary sewage? An analysis of the macro-drainage system in a medium-sized city in the Northeast Region

RESUMO A concepção dos sistemas de drenagem de águas pluviais como separador absoluto é uma característica marcante na gestão das águas urbanas, no entanto não é o reflexo da realidade de tal sistema na maioria das cidades brasileiras, onde frequentemente esgotos e águas pluviais escoam pelos mesmos condutos. Diante disso, o objetivo do presente trabalho foi investigar as contribuições de contaminação fecal dos canais de drenagem afluentes ao Canal do Prado, pertencentes ao sistema de macrodrenagem de águas pluviais da cidade de Campina Grande, na Paraíba. Para a realização da pesquisa de campo, foram definidos sete pontos de monitoramento ao longo do canal e, como indicadores de contaminação fecal, coliformes termotolerantes, Escherichia coli e os ovos dos helmintos Ascaris lumbricoides, Taenia sp, Hymenolepis nana, Hymenolepis diminuta, Enterobius vermicularis, Ancilostomideo sp e Trichuris sp. Os resultados apontaram que ovos de Ascaris lumbricoides foram os que apresentaram maior frequência nos pontos de monitoramento, relacionados à maior descarga de esgotos sanitários. Tais descargas também foram verificadas por elevados valores médios de coliformes termotolerantes que atingiram até 1,6 x 107 UFC.100 mL-1, valor típico de esgoto sanitário. Escherichia coli ocorreu em mais de 90% das amostras coletadas em todos os pontos de monitoramento.

ABSTRACT The design of rainwater drainage systems as an absolute separator is a significant feature in urban water management, however, this is not a reflection of the reality of such a system in most Brazilian cities, where sewage and rainwater often run along the same path. Therefore, the aim of this study was to investigate contributions of fecal contamination from tributary drainage channels to Canal do Prado, belonging to the urban macro-drainage system of rainwater in the city of Campina Grande, Paraíba State. For the fieldwork, seven monitoring points were set along the channel object of this study, determining thermotolerant coliforms, Escherichia coli, and helminth eggs of Ascaris lumbricoides, Taenia sp, Hymenolepis nana, Hymenolepis diminuta, Enterobius vermicularis, and Trichuris sp, as fecal contamination indicators. The results pointed out that eggs of Ascaris lumbricoides were those with the highest frequency in monitoring points, being this related to the increased discharge of sewage. Such discharges were also verified by high mean values of thermotolerant coliforms that reached up to 1.6 x 107 CFU.100 mL-1, typical value of domestic sewage. Escherichia coli was present in over 90% of all samples collected from monitoring points.

Validação de método analítico por extração líquido-líquido e análise por cromatografia gasosa acoplada à espectrometria de massas para detecção de ácidos haloacéticos em amostras ambientais / Validity of the analytical method of LLE-GC-MS for the detection of haloacetics acids in environmental samples

RESUMO O estudo teve como objetivo o desenvolvimento e a validação de um método analítico para detecção e quantificação de ácidos haloacéticos por meio da extração líquido-líquido e da análise por cromatografia gasosa acoplada à espectrometria de massas. Para a validação, consideraram-se parâmetros como linearidade, precisão, limites de detecção e quantificação e seletividade. Adicionalmente, aplicou-se o método para avaliar a formação de ácidos haloacéticos em ensaios de cloração de células de Cylindrospermopsis raciborskii com o oxidante hipoclorito de cálcio, simulando situações em estações de tratamento de água. O método apresentou baixo tempo de análise, excelente seletividade, precisão, repetitividade e sensibilidade, com possibilidade de aplicação para análises de rotina em substituição à cromatografia a gás por captura de elétrons. Observou-se a formação de ácidos haloacéticos durante os ensaios com doses de 2,5 e 5,0 mg.L-1 do oxidante, com destaque para os ácidos dicloroacético e tricloroacético.

ABSTRACT The objective of the study was to develop and validate an analytical method for the detection and quantification of haloacetic acids through liquid-liquid extraction and gas chromatography-mass spectrometry analysis. For validation, parameters such as linearity, precision, detection and quantification limits, and selectivity were considered. Additionally, the method was applied to evaluate the formation of haloacetic acids in in Cylindrospermopsis raciborskii cell chlorination assays with the calcium hypochlorite oxidant, simulating full scale situations in water treatment plants. The method presented low analysis time, excellent selectivity, precision, repeatability, and sensitivity, with possibility of application for routine analysis in substitution gas chromatography by electron capture. The formation of haloacetic acids was observed during the tests with 2.5 and 5.0 mg.L-1 doses of the oxidant, with emphasis on dichloroacetic and trichloroacetic acids.

Avaliação de fatores intervenientes no desempenho de estações de tratamento de água / Evaluation intervening factors in the performance of water treatment plants

RESUMO O objetivo do trabalho consistiu em avaliar a influência da sazonalidade, da eventual sobrecarga hidráulica, do porte, do custo e da idade no desempenho de estações convencionais de tratamento de água pela análise de confiabilidade como ferramenta de avaliação. Para tal, empregaram-se dados operacionais do efluente de 20 estações operadas pelo mesmo prestador referentes ao período 2009-2014. As análises estatísticas mostraram que o desempenho, em termos de turbidez do efluente, elevou-se no período de estiagem em relação ao chuvoso e nas unidades de pequeno porte avaliadas. No mesmo contexto, a quase totalidade das estações submetidas à sobrecarga hidráulica apresentou desempenho inferior. A determinação da faixa de turbidez requerida na saída da estação, pela análise de confiabilidade, mostrou-se importante ferramenta de gestão permitindo hierarquizar ações de melhorias nos sistemas. Não se verificou correlação entre o nível de confiabilidade e o custo do tratamento e a idade da estação.

ABSTRACT The objective of this work was to evaluate the influence of seasonality, possible hydraulic overload, size, cost, and age of the station in the performance of conventional water treatment stations based on reliability analysis as an evaluation tool. For this purpose, operational data of the effluent from 20 stations operated by the same provider for the 2009-2014 period were used. Statistical analyses showed that the performance was increased in the dry season compared to the rainy one and in the small units evaluated. In the same scenario, almost all the stations submitted to hydraulic overload exhibit inferior performance. The determination of turbidity range required at the exit of the station, through the reliability analysis, proved to be an important management tool, allowing to hierarchize improvement actions in the systems. In addition, there was no correlation between the level of reliability and the treatment cost and the age of the station.

Preliminary assessment of antimicrobial activity and acute toxicity of norfloxacin chlorination by-product mixture.

Among drugs and personal care products, antibiotics arouse interest since they are widely used in human and veterinary medicine and can lead to the development of bacterial resistance. Usually, sewage treatment does not remove most of these compounds. So, these drugs can reach water treatment plants (WTP), where disinfection with chlorine compounds is common. This work aimed to evaluate the antimicrobial activity and preliminary toxicity of the mix of by-products forming due to the chlorination of norfloxacin. This is a fluoroquinolone antibiotic indicated for the treatment of urinary infection and gonorrhea, with sodium hypochlorite (NaClO). The drug was subjected to chlorination tests, on a bench scale, with several reaction times (from 5 min to 24 h). Analyses of high-resolution mass spectrometry (MS) were performed for the characterization of the by-products. The MS results showed five peaks attributed to the by-products' formation, of which four were identified. The antibiogram results indicated that the solution that contained the mixture of the by-products lost antibacterial activity against the E. coli strain studied. The acute toxicity tests for the Artemia salina microcrustacean showed that the blend of the by-products exhibited higher toxicity than pure norfloxacin.

Water tariff forecasting models applied to municipal and private companies in the south and southeast regions of Brazil.

This paper has as a main goal to evaluate how models of the forecast will work with a group of variables that were selected based only on their correlation with the average tariff variation. Two forecast models are used, the first based on multiple linear regression techniques and the second based on the application of artificial neural networks (perceptron). We intend to use those models to reach the current water tariff based on the historic variation of the charge and the selected variables applied to municipal and private companies that operate water supply and wastewater systems in the South and Southeast regions of Brazil. The subsidiary data for the elaboration of the models were obtained through the National Sanitation Information System (SNIS). The obtained results indicated that the forecasting processes, in both models used, were able to forecast with high accuracy the fees, and guaranteed the maintenance of the surplus for the analyzed systems.

Response surface methodology applied to tropical freshwater treatment.

This paper presents the profits and disadvantages of the chemometrics approach instead of the one-factor-at-a-time (OFAT) coagulation diagram approach for tropical water physicochemical treatment. Central composite design associate to response surface methodology (CCD-RSM) is used to find the real best conditions for coagulant dosage and pH aiming at high-turbidity removal. The number of experiments needed to chemometrics model construction (12) is comparatively smaller than that used in the coagulation diagram (84), saving financial and environmental resources. Arguments for Water Treatment Plants (WTP) considering the replacement of coagulation diagram approach by the CCD-RSM approach in drinking water treatment are presented. Chemometrics models are all constructed on a free software platform, providing the best pH within the range 7.7-8.1, and the best coagulant dosage (polyaluminium chloride, PAC) between 2.0 and 3.1 mg Al2O3 L-1 (equivalent in mass). CCD-RSM provides a faster, lower-cost and more reliable alternative tool for WTP decision-making instead of the OFAT model, mainly for waters more affected by seasonal effects as can be seen in tropical and subtropical countries.

Avaliação de indicadores aplicados a sistemas de abastecimento de água de pequeno porte / Evaluation of indicators applied to small water supply systems

RESUMO O presente trabalho visou avaliar, por meio de regressão linear múltipla (RLM), os indicadores que melhor exprimem a realidade dos sistemas de abastecimento de água de municípios de pequeno porte, com base nos desempenhos financeiro, operacional e de qualidade da água como variáveis de resposta. A organização e a seleção dos dados fiaram-se no Sistema Nacional de Informações sobre Saneamento de 2014, tendo sido selecionados os referentes a 182 municípios de Minas Gerais com população inferior a 10 mil habitantes e 56 indicadores como variáveis explicativas. Por meio da RLM, verificou-se que o comprometimento das receitas com a despesa (margem da despesa de exploração) e a razão entre a arrecadação e as despesas (índice de suficiência de caixa) são as variáveis mais relevantes para descrever o desempenho financeiro. Para descrição do desempenho operacional, os índices de perdas por ligação e de faturamento de água foram os mais recorrentes. Por fim, no que tange ao desempenho de qualidade da água, os modelos apresentaram baixos coeficientes de determinação e a não aderência dos resíduos à distribuição normal.

ABSTRACT The aim of this study was to evaluate, by means of multiple linear regression (MLR), the indicators that best express the reality of small municipalities water supply systems, based on financial, operational and water quality performance as response variables. The organization and selection of the sample were based on the information available in the National Sanitation Information System of 2014, selecting 182 municipalities in Minas Gerais with population below 10,000 inhabitants and 56 indicators as explanatory variables. Through MLR, it was found that the commitment of revenue to expenditure (operating expense margin) and the ratio of collection to expenses (monetary sufficiency index) are the most relevant variables to describe financial performance. For the description of operational performance, the water loss per connection and water billing rates were the most recurrent. Finally, with regard to the performance of water quality, the models presented low determination coefficients and non-adherence of the residues to normal distribution.

Estimativa do dispêndio de água virtual nas exportações brasileiras no período de 2003 a 2014 / Estimation of virtual water use in Brazilian exports from 2003 to 2014

RESUMO O conceito de água virtual tem sido muito utilizado como importante indicador de consumo, sendo cada vez mais aceito na literatura, constituindo-se da água incorporada à produção de um bem ou serviço. Visando a estimar o volume de água virtual presente nos 25 principais produtos da pauta de exportação brasileira no período 2003-2014, utilizou-se o método de pesquisa exploratória a partir dos principais produtos que representavam aproximadamente 60% do montante arrecadado. Os resultados indicaram inflexão entre a relevância dos produtos manufaturados e dos produtos básicos (principalmente minério de ferro e soja) no período de 2009-2010, com apenas quatro produtos respondendo, em 2014, por 32% da receita auferida pelo País. Como consequência, a estimativa do dispêndio de água virtual realizada para os produtos avaliados indicou que o Brasil despendeu, em média, 191 Gm3.ano-1 (6.025 m3.s-1), com os produtos básicos respondendo por 95% desse volume. Considerando-se apenas 2014, essa vazão elevou-se para 7.836 m3.s-1, aproximadamente 14 vezes superior à demanda para abastecimento da população urbana brasileira.

ABSTRACT The Virtual Water concept has long been used as an important indicator of water consumption, increasingly being accepted in the literature, becoming the embedded water in the production of a good or service. In order to estimate the volume of virtual water present in the top 25 products of Brazilian exports in the period 2003-2014, we used the exploratory method from the main products that represented approximately 60% of the collected amount. Results indicated a shift between the relevance of manufactured products and commodities (mainly iron ore and soybeans) in the 2009-2010 period, with only four products accounting in 2014 for 32% of the revenue earned by the country. As a result, the estimated virtual water expenditure for the products evaluated indicated that Brazil spent, on average, 191 Gm3.year-1 (about 6,025 m3.s-1), with commodities accounting for 95% of this volume. Considering only 2014, this flow increased to about 7,836 m3.s-1, 14 times higher than the supply demand of the Brazilian urban population.

Aplicação de análise multivariada no estudo da frequência de amostragem e do número de estações de monitoramento de qualidade da água / Multivariate analysis applied for study of the sampling frequency and the number of sampling stations in water quality monitoring

RESUMO O cerne do presente trabalho consistiu em aplicar ferramentas de análise exploratória multivariada objetivando avaliar o número de estações de monitoramento de qualidade da água e a frequência de amostragem. Para tal, utilizou-se banco de dados disponibilizado pelo Instituto Mineiro de Gestão das Águas (IGAM) referente à Bacia do Rio das Velhas, na região central mais populosa de Minas Gerais. Foram utilizadas as técnicas de análise das componentes principais (ACP) e a rede neural de Kohonen, que culminaram na significativa redução da frequência de amostragem, em alguns casos de mensal para anual ou semestral, e na redução do número de estações de monitoramento de 36 para 33. Os resultados permitem abrir a possibilidade do emprego dos métodos utilizados como ferramentas de gestão de recursos hídricos de bacias hidrográficas visando à otimização dos programas de monitoramento de qualidade de água.

ABSTRACT The core of this work consisted of applying multivariate exploratory analysis tools to evaluate the number of water quality monitoring stations and the sampling frequency. In such way, the database provided by the Minas Gerais Institute of Water Management (IGAM) on the river basin of Rio das Velhas, in the most populous central region of Minas Gerais state, was used. The Principal Components Analysis and the Kohonen neural network techniques were applied, resulting in a significant reduction in sampling frequency, in some cases from monthly to annual or semi-annual, and in the reduction of the number of monitoring stations from 36 to 33. The results open the possibility of using these methods as watershed water resources management tools aimed at optimization of water quality monitoring programs.

Proposta de padronização para não conformidades aplicadas à fiscalização de sistemas de abastecimento de água por agências reguladoras / Standard proposal of nonconformities applied to inspection of water supply systems by regulatory agencies

RESUMO O presente estudo teve como objetivo propor uma padronização de não conformidades aplicadas à fiscalização direta de sistemas de abastecimento de água, com base nos instrumentos normativos do setor de saneamento e na experiência de agências reguladoras de âmbito nacional. Elaborou-se uma lista de itens para fiscalização fundamentada na análise de checklist e resoluções normativas disponíveis nos sítios eletrônicos de três agências reguladoras. A listagem compreendeu todas as unidades do sistema e os aspectos referentes à qualidade da água. Os 179 itens abordados foram enquadrados em: não conformidades (80); sujeitos à recomendação da agência (56); e de caráter informativo (43). Essa proposta visa ao aprimoramento dos instrumentos de fiscalização e da atividade regulatória, visto que um dos objetivos da regulação é o estabelecimento de padrões e normas à adequada prestação dos serviços e à satisfação dos usuários. Adicionalmente, a padronização das não conformidades permitirá comparações mais fidedignas entre sistemas de abastecimento, favorecendo a avaliação do desempenho dos prestadores e a melhoria contínua dos serviços.

ABSTRACT This study proposes a standardization of nonconformities applied to direct inspection of water supply systems using legal instruments of sanitation sector and national regulatory agencies' experience. From the analysis of checklist and normative resolutions available in three regulatory agencies websites - ARCE, ARSI and ARES-PCJ - and of regulatory provisions related to sanitation, a list of items to check supply systems in direct inspection was made. The list includes all system units, from the water catchment areas to distribution network, besides the aspects of water quality. The items discussed were classified as: non-conformities; subject to the agency's recommendation and; for informational purposes only. The final document provides a list of 179 items for water supply systems' inspection, being 80 nonconformities, 56 items subject to the agency's recommendation and 43 items for information purposes only. This proposal is notable for the perspective of improvement supervisory tools and regulatory activity, since one of the regulation's objectives is to establish standards and norms for the adequate provision of services and customer satisfaction. In addition, the standardization of nonconformities allows for a better comparison between water supply systems from the weaknesses identified by the inspections to enable performance evaluation of service providers and encourage continuous improvement of public services.

Avaliação quantitativa e qualitativa do emprego de paredes como nova perspectiva para captação de água de chuva / Quantitative and qualitative evaluation of the use of walls as a new perspective of rainwater harvesting

RESUMO A poluição dos mananciais de abastecimento e a necessidade de se buscar água, cada vez mais distante, agregam à água tratada alto valor monetário, sendo a captação e a utilização da água de chuva uma forma de reduzir custos. Nos grandes centros urbanos, ocorre a formação de ilhas de calor, as quais favorecem a ocorrência de chuvas convectivas dotadas de ventos. Além disso, houve a verticalização das edificações, resultando em área lateral maior, se comparada com a do telhado, tornando a captação de água pluvial em paredes uma alternativa promissora. O objetivo deste trabalho foi verificar a quantidade e a qualidade da água captada em uma parede de vidro e outra de argamassa pintada na cidade de Ilha Solteira, São Paulo. A média de incidência da chuva foi de 48,7% na parede de vidro e 33,3% na de argamassa pintada, tendo cada anteparo uma eficiência de captação média de 16,21 e 8,27%, respectivamente. Os parâmetros de qualidade da água (pH, turbidez, condutividade elétrica e alcalinidade) apresentaram diminuição com o passar dos milímetros escoados. A água proveniente na parede de vidro não necessita de volume de descarte, de acordo com a Norma Brasileira (NBR) nº 15527/07. Não foi encontrada relação entre a intensidade da chuva e a qualidade da água, bem como com a eficiência de captação. Porém, quando ocorreram precipitações em dias consecutivos a qualidade da água foi superior, confrontada com a ocorrência de períodos secos.

ABSTRACT The pollution of water supply sources and the need to seek water, which is increasingly distant, adds to the treated water a high monetary value, so the capture and use of rainwater represents a way to reduce costs. In large urban centers, the formation of heat islands takes place, which favors the occurrence of convective rains with winds. Furthermore, the buildings were verticalized, resulting in a larger lateral area compared to that of the roof, making the rainwater-harvesting in walls a promising alternative. The aim of this work was to verify the quantity and quality of the water collected on a glass wall and another concrete wall in the city of Ilha Solteira, São Paulo, Brazil. The average rainfall incidence was of 48.7% in the glass wall and of 33.3% in the concrete wall, with each screen having an average pickup efficiency of 16.21 and 8.27%, respectively. The parameters of water quality (pH, turbidity, electrical conductivity and alkalinity) presented a decrease with the passing of millimeters drained. Water from the glass wall requires no volume of waste according to NBR 15.527/07. No relation was found between rainfall intensity and water quality, as well as catchment efficiency. However, when rainfall occurred on consecutive days, the water quality was higher when compared to its occurrence in dry periods.

Proposição de sistema de indicadores de desempenho operacional de estações de tratamento de água à luz do prestador de serviço: aplicação a cinco estações de ciclo completo / Proposition of operational performance indicators system applied for water treatment plants focusing on service provider: application for five conventional water treatment plants

RESUMO O principal objetivo desta pesquisa consistiu em desenvolver e aplicar um sistema de indicadores de desempenho direcionado a estações convencionais de tratamento de água com base na visão do prestador de serviço. A metodologia abrangeu três etapas principais: (i) definição dos indicadores e justificativa; (ii) formulação e aplicação do sistema de indicadores a um conjunto de cinco estações de pequeno porte (vazões nominais de 20 a 60 L.s-¹) operadas pelo mesmo prestador; (iii) análise estatística a partir dos resultados de cálculo dos indicadores visando identificar eventuais sobreposições. O sistema proposto abarcou 13 indicadores de desempenho, calcados em parâmetros comumente inseridos na rotina operacional das estações de tratamento brasileiras.

ABSTRACT The main objective of this research was to develop and apply a performance indicator system focusing on conventional water treatment plants, based on the service provider's point of view. The methodology comprised three principal steps: (i) definition of indicators and justification; (ii) development and application of the indicator system to five small plants (flow rate from 20 to 60 L.s-1) operated for same provider; (iii) statistical analysis of the results, aiming to identify overlapping among the proposed performance indicators. The system comprised 13 performance indicators whose application is based on parameters usually monitored in the vast majority of Brazilian plants.

Oxidação de fármacos por cloro e formação de subprodutos em amostras aquosas em escala de bancada / Pharmaceuticals oxidation by chlorine and byproducts formation in aqueous matrices in bench scale

RESUMO Fármacos e desreguladores endócrinos são encontrados em águas naturais brasileiras, incluindo alguns mananciais de abastecimento, também em função da baixa cobertura de coleta e tratamento de esgotos no Brasil. Nesse cenário, o presente trabalho intentou avaliar a remoção de três fármacos - sulfametoxazol (SMX), diclofenaco (DCF) e 17β-estradiol (E2) - em água destilada por meio da oxidação com cloro (hipoclorito de sódio), variando-se a dose de cloro e o tempo de contato em ensaios de batelada. As soluções cloradas foram analisadas, ainda, por cromatografia acoplada à espectrometria de massas para identificação de eventuais subprodutos de oxidação. Para tempo de contato de 10 min e dose de cloro de 1,5 mg.L-1, foi observada remoção média de 61% para DCF, 36% para E2 e 33% para SMX. Apenas para o DCF verificou-se diferença estatisticamente significativa (α=0,05) para dose de cloro de 3,0 mg.L-1. A oxidação seguiu modelo cinético de pseudossegunda ordem, com valores de k2 de 0,0168 L.µg.min-1 para SMX (para ambas doses testadas), de 0,0133 e 0,0798 L.µg.min-1 para DCF, e de 0,0326 e 0,0289 L.µg.min-1 para E2, para doses de cloro de 1,5 e 3,0 mg.L-1, respectivamente. Por fim, verificou-se que o aumento do tempo de contato favoreceu a oxidação dos fármacos, ainda que com a perspectiva de formação de subprodutos para SMX e E2.

ABSTRACT Pharmaceuticals and endocrine disrupting compounds are found in Brazilian natural waters, including some water sources for public supply, also due to the low coverage of sewage collection and treatment in Brazil. This study investigated the removal of three pharmaceutical compounds - sulfamethoxazole (SMX), diclofenac (DCF) and 17β-estradiol (E2) - from aqueous solutions by means of chlorine oxidation (sodium hypochlorite) by varying the dose of chlorine and contact time in batch tests. The chlorine solutions were examined by chromatography attached to the mass spectrometry in order to identify the oxidation by-products. For 10 min contact time, mean removal values of 61% were observed for DCF; 36% for E2; and 33% for SMX, when the chlorine dose was 1.5 mg L-1. Just for DCF there was a statistically significant difference (α=0.05) in the removal efficiency when increasing the chlorine dose to 3.0 mg.L-1. The oxidation followed the kinetic model of pseudo-second order, with k2 values of 0.0168 L.µg.min-1 for SMX (at both chlorine doses tested); 0.0133 and 0.0798 L.µg.min-1 to DCF; and 0.0326 and 0.0289 L.µg.min-1 to the E2 at chlorine doses of 1.5 and 3.0 mg L-1, respectively. Finally, it was verified that an increase of the contact time favored the oxidation of all pharmaceuticals tested, although with the perspective of by-products formation for SMX and E2.

Fármacos e desreguladores endócrinos em águas brasileiras: ocorrência e técnicas de remoção / Pharmaceuticals and endocrine disrupting compounds in Brazilian waters: occurrence and removal techniques

RESUMO As ações antrópicas têm fomentado a presença de diversos microcontaminantes nos corpos d'água. Desses, mais recentemente, os fármacos e os desreguladores endócrinos têm chamado a atenção da comunidade científica acerca da crescente exposição dos corpos d'água a esses fármacos e desreguladores. As fontes de contaminação englobam produtos de limpeza e higiene pessoal, fármacos de diversas classes, hormônios naturais e seus subprodutos, além de diversas substâncias aplicadas na produção de plásticos e resinas, presentes nos esgotos sanitários, lixiviados de aterro e efluentes industriais. Nessa perspectiva, o artigo presta-se a compilar os dados de ocorrências desses microcontaminantes em águas brasileiras naturais e tratadas assim, como a discutir a eficiência de diferentes técnicas de tratamento de água na remoção de tais contaminantes.

ABSTRACT The human activities have increased the presence of several microcontaminants in water bodies. Of these, more recently, drugs and endocrine disrupters have called the attention of the scientific community due to their increasing exposure. The sources of contamination include cleaning and personal hygiene products, various classes of drugs, natural hormones and their by-products, as well as several substances applied to the production of plastics and resins, present in sewage, landfill leachate and industrial effluents. In this perspective, this paper aims to compile the data of microcontaminants occurrence in Brazilian natural and treated waters, as well as to discuss the efficiency of different water treatment techniques to remove such compounds.

Hierarquização da eficiência de remoção de cianotoxinas por meio de adsorção em carvão ativado granular / Evaluation of hierarchy of cyanotoxin removal by adsorption onto granular activated carbon

RESUMO O trabalho objetivou avaliar a remoção concomitante de duas cianotoxinas - microcistina-LR e saxitoxina-STX - por meio da adsorção em carvão ativado granular. Em primeira etapa, três carvões de granulometrias distintas, dois de coco de dendê e um mineral, foram avaliados na adsorção de microcistina-LR em água destilada e tratada com concentrações de 3,9 a 9,4 ug.L-1. O carvão de coco de dendê de menor granulometria apresentou desempenho mais uniforme, tanto no que tange à remoção (%) de microcistina-LR, quanto ao volume de efluente produzido consoante com as recomendações do padrão de potabilidade brasileiro. Em segunda etapa, apenas para o carvão selecionado na etapa precedente, concentrações de microcistina-LR e saxitoxina-STX aproximadamente 50% superiores dos limites do mesmo padrão de potabilidade foram dispersas em água destilada. Tais ensaios de adsorção evidenciaram que apenas a adsorção de saxitonina não foi influenciada pela simultaneidade das duas cianotoxinas.

ABSTRACT This study focused on the simultaneous removal of two cyanotoxins - microcystin-LR and saxitoxin-STX - by means of adsorption onto granular activated carbon. In first step, three carbons with different granulometry (dende coconut and mineral) were evaluated on adsorption of microcystin-LR in distilled and treated waters in concentrations at about 3.9 to 9.4 ug.L-1. The dende coconut carbon with lower granulometry showed higher performance according to the limits established by Brazilian Drinking Water Standards. In second step, with the selected carbon in previous step, concentrations of the two cyanotoxins 50% higher than those limits were dispersed in distilled water. The tests pointed out that only saxitoxin-STX removal was not affect by the presence both cyanotoxins.

Comparison between two forms of granular activated carbon for the removal of pharmaceuticals from different waters.

The aim of this study was to evaluate the performance of two forms of basic granular activated carbon (GAC), mineral (pH = 10.5) and vegetal (pH = 9), for the removal of three pharmaceuticals, as sulphamethoxazole (SMX), diclofenac (DCF) and 17ß-estradiol (E2), from two different matrices: fortified distilled (2.4-3.0 mg L(-1) and pH from 5.5 to 6.5) and natural (∼1.0 mg L(-1) and pH from 7.1 to 7.2) water in a bench scale. The Rapid Small-Scale Column Test used to assess the ability of mineral and vegetal GAC on removal of such pharmaceuticals led to removal capacities varying from 14.9 to 23.5 mg g(-1) for E2, from 23.7 to 24.2 mg g(-1) for DCF and from 20.5 to 20.6 mg g(-1) for SMX. Removal efficiencies of 71%, 88% and 74% for DCF, SMX and E2, respectively, were obtained at breakthrough point when using mineral GAC, whereas for the vegetal GAC the figures were 76%, 77% and 65%, respectively. The carbon usage rate at the breakthrough point varied from 11.9 to 14.5 L g(-1) for mineral GAC and from 8.8 to 14.8 L g(-1) for vegetal GAC. Mineral CAG also exhibited the best performance when treating fortified natural water, since nearly complete removal was observed for all contaminants in the column operated for 22 h at a carbon usage rate of 2.9 L g(-1).