ABSTRACT
Resumo Águas distribuídas para abastecimento público precisam obedecer ao padrão de potabilidade em vigor para que sejam sanitariamente seguras, visando não expor a população abastecida a riscos epidemiológicos inerentes às doenças de veiculação hídrica. Este trabalho teve como objetivo avaliar a qualidade da água distribuída aos habitantes de três bairros da cidade de Rio Verde, em Goiás. Foram realizadas quatro coletas semanais nos dias 7, 14, 21 e 28 do mês de dezembro de 2012, em três pontos selecionados. Os parâmetros analisados foram temperatura (T), sólidos totais dissolvidos (STD), condutividade elétrica (CE), turbidez (Turb), pH, cloro residual livre (CRL), coliformes totais (CT) e Escherichia coli (E. coli). As médias dos resultados foram comparadas com os limites estabelecidos pela Portaria do Ministério da Saúde nº 2.914/2011. Todas as amostras atenderam aos limites determinados pela referida Portaria com relação aos parâmetros STD, Turb, pH, CT e E. coli. O sistema de abastecimento de água analisado apresentou inconformidade quanto ao nível de CRL em dois bairros, o que pode comprometer a saúde da população atendida. Os procedimentos operacionais na etapa de desinfecção do tratamento da água devem ser retificados para que os níveis de CRL na rede de distribuição atendam aos limites legais.
Abstract Water distributed for public supply must comply with the standard potability in order to be sanitarily safe and not to expose the supplied population to epidemiological risks inherent to waterborne diseases. This study aimed to evaluate the quality of the water distributed to residents of three neighborhoods in the city of Rio Verde, Goiás state. Four samples were collected per week on December 7th, 14th, 21st and 28th 2012, at the three locations selected. The parameters analyzed were temperature, total dissolved solids, conductivity, turbidity, pH, free residual chlorine, total coliforms and Escherichia coli. The average results were compared with the limits established by the Ministry of Health Ordinance No. 2914 of 2011. All the samples met the limits established by that order related to total dissolved solids parameters, turbidity, pH, total coliforms and Escherichia coli. The analyzed water supply system presented unconformity regarding the free residual chlorine level in two neighborhoods, which can compromise the health of the population served. The operational procedures in the water treatment disinfection step must be rectified so that the free residual chlorine levels in the distribution network meet the legal limits.
ABSTRACT
Eucalyptus bleached kraft pulp production, an important sector of the Brazilian national economy, is responsible for generating large volume, high pollutant load effluents, containing a considerable fraction of recalcitrant organic matter. The objectives of this study were to quantify the biological activity of the effluent from a eucalyptus bleached kraft pulp mill, characterize the nature of compounds responsible for biological activity and assess the effect of ozone treatment on its removal. Primary and secondary effluents were collected bimonthly over the course of one year at a Brazilian bleached eucalypt kraft pulp mill and their pollutant loads (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), adsorbable organic halogen (AOX), lignin, extractives) and biological activity (acute and chronic toxicity and estrogenic activity) quantified. The effluent studied did not present acute toxicity to Daphnia, but presented the chronic toxicity effects of algal growth inhibition and reduced survival and reproduction in Ceriodaphnia, as well as estrogenic activity. Chronic toxicity and estrogenic activity were reduced but not eliminated during activated sludge biological treatment. The toxicity identification evaluation revealed that lipophilic organic compounds (such as residual lignin, extractives and their byproducts) were responsible for the toxicity and estrogenic activity. Ozone treatment (50 mg/L O(3)) of the secondary effluent eliminated the chronic toxicity and significantly reduced estrogen activity.
