Evaluation of water quality at the source of streams of the Sinos River Basin, southern Brazil

Abstract

The Sinos River Basin (SRB) is located in the northeastern region of the state of Rio Grande do Sul (29°20' to 30°10'S and 50°15' to 51°20'W), southern Brazil, and covers two geomorphologic provinces: the southern plateau and the central depression. It is part of the Guaíba basin, has an area of approximately 800 km 2 and contains 32 counties. The basin provides drinking water for 1.6 million inhabitants in one of the most important industrial centres in Brazil. This study describes different water quality indices (WQI) used for the sub-basins of three important streams in the SRB: Pampa, Estância Velha/Portão and Schmidt streams. Physical, chemical and microbiological parameters assessed bimonthly using samples collected at each stream source were used to calculate the Horton Index (HI), the Dinius Index (DI) and the water quality index adopted by the US National Sanitation Foundation (NSF WQI) in the additive and multiplicative forms. These indices describe mean water quality levels at the streams sources. The results obtained for these 3 indexes showed a worrying scenario in which water quality has already been negatively affected at the sites where three important sub-basins in the Sinos River Basin begin to form.Keywords: water quality index (WQI), monitoring, Pampa stream, Estancia Velha/Portão stream, Schmidt stream. Avaliacão da qualidade da água das nascentes de arroios da Bacia do Rio dos Sinos, região sul do Brasil ResumoA Bacia Hidrográfica do Rio dos Sinos (BHRS) está localizada na região Nordeste do Estado do Rio Grande do Sul (29°20' to 30°10'S and 50°15' to 51°20'W), na região Sul do Brasil, envolvendo duas regiões geomorfológicas, o planalto Sul e a depressão central. Esta bacia faz parte da Bacia do Guaíba e tem uma área de aproximadamente 800 km 2 , atingindo 32 municípios. A BHRS fornece água de abastecimento para cerca de 1.6 milhões de habitantes e para um dos mais importantes centros industriais do Brasil. Este artigo apresenta a determinação de diferentes índices de qualidade de água (IQA) para as regiões de nascente de três importantes sub-bacias pertencentes à BHRS: arroios Pampa, Estância Velha/Portão e Schmidt. Utilizando parâmetros físicos, químicos e microbiológicos, analisados em amostras coletadas bimestralmente em cada ponto próximo à nascente, foram calculados os índices de Horton (IH), de Dinius (ID) e o índice de qualidade de água da National Sanitation Foundation, EUA (IQANSF) usando os métodos somatório e produtório. Os resultados foram analisados para verificação da qualidade da água nos pontos amostrais a fim de comparar e classificar a água na região das nascentes das três sub-bacias. Uma avaliação conjunta dos índices calculados indicou que a água nos três pontos amostrais apresenta qualidade média. Os resultados dos três índices convergem a um cenário preocupante que indica que, desde os pontos iniciais de formação de três importantes sub-bacias do rio dos Sinos, já ocorrem problemas de qualidade de água.Palavras-chave: índices de qualidade de água (WQI), monito...

Assessment of Groundwater Quality in the Talensi District, Northern Ghana

“…Nevertheless, water that is deemed fit for one purpose may be undesirable for another, as such an integrated approach which incorporates all the relevant chemical parameters of interest, usually guided by WHO [20], and local e Scientific World Journal drinking water standards in a particular groundwater system is relevant in characterising the suitability of water domestic for purpose. e water quality index (WQI) has been adopted by many studies for such purposes [48][49][50][51][52]. e same has been adopted in this study, the weighted arithmetic index approach modified after Brown et al [53], to assess the quality of groundwater for drinking purposes.…”

Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

“…This scenario is mainly constructed by the large amount of domestic sewage produced by urban basins (Gillis, 2012;Janse et al, 2015;Konzen et al, 2015;Benvenuti et al, 2015), intensified by rainfall that potentializes the concentration of nitrogen and phosphate compounds leading to a general eutrophication state (Cunha et al, 2010;Paula et al, 2010;Butiuc-Keul et al, 2012).…”

“…Anthropic pressure is the classic driver of environmental change. It results from disorganized urban occupation around lakes, rivers, and estuaries, which makes them increasingly vulnerable (Williamson et al, 2008;Benvenuti et al, 2015). This urban population leads to the pollution of the river basin, which restricts the use of its waters for drinking, industry, agriculture, and leisure, and may threaten the integrity of its aquatic ecosystems (Carey et al, 2013;Massoud, 2012).…”

Assessment of a Physicochemical Indexing Method for Evaluation of Tropical River Water Quality

“…Fernandez et al [21] compared 36 water quality indices revealing that DO, TS, pH, FCC, BOD, total phosphorus, and nitrate are the most common parameters followed by Turb, Temp, and ammonia with similar importance. Although pH is obviously a parameter most conveniently measured for the calculation of WQI, Benvenuti et al [22] asserted that pH and Temp are insignificant discriminants for the assessment of water quality. For subindices derivation, multiple functions were employed.…”

“…This implies considerable influence of FCC over the resultant index. Benvenuti et al [22] evaluated the water quality of Sinos River Basin in South Brazil using three different indexing methods. It was concluded from the results that an index that comprises significant discriminants with adequate weightage is essential for a more representative evaluation of water quality.…”