Evaluation of pollution level caused by domestic effluent in the Poty river – Teresina PI - Brazil

Abstract

waters serve a variety of purposes such as public water supply, watering livestock, irrigation of agricultural crops, conservation of flora and fauna, recreation and lounge [15].The urban area of the Poty River in Teresina receives in its bed twenty-three sewers without any pre-treatment. Teresina has more than eight hundred and six thousand inhabitants and only 13% of the population has access to a sewage system. Moreover, this population often has the largest collective network but the parent company of water and sewerage services of Teresina (Agua e Esgoto do Piauí/SA -AGESPISA) did not make the connection to the network of people's homes [15].The economic and social development of cities or countries is based on the availability of water quality and in the ability to conserve and protect watersheds. The quantification of the pollutant load of a water body is the key of to any management that focuses on the conservation and sustainable use of water [16]. This study aimed to analyze the level of pollution in the urban area of the Poty River in Teresina. The results were analyzed using multivariate tools (Principal Component Analysis-PCA) which allowed an assessment of the environmental impact caused by waste disposed in the bed of the river without any pretreatment. IntroductionWaterways pollution has worsened terribly after the construction of domestic sanitary sewage plants that dump its polluted contents into the rivers, sea, etc.[1] The accumulation of city-generated solid waste that is washed away by the rain can also cause pollution in water bodies. The poor quality of urban sanitation and lack of public awareness have brought great damage to storm water quality [2][3][4][5] Metals differ from toxic organic compounds in that they are absolutely non-degradable, so they may accumulate in the environment where their toxicity is manifested. Many studies [2][3][4][5] have been developed in order to quantify metals in river water and these studies have shown that the concentrations of some metals are very high, and therefore can cause serious environmental problems regarding water and sediments [5,[10][11][12][13][14]. The main sources of contamination from these rivers are from various human activities [2][3][4] The Poty river, the subject of this study, has a semi-perennial watercourse that runs 550 km long. It is one of the most predominant of Parnaiba, with its origin in Joaninha Serra, in the state of Ceará. Its basin is 49,800 km², and reaches 27 municipalities, eleven of those being in the state of Ceará and 16 in Piauí. Its This article reports on the level of contamination of effluents, sediments and water in the Poty River, within the city of Teresina. The samples were collected in the months of September 2009, December 2009 and March 2010. The results of some physico-chemical parameters investigated, as well as the concentrations of lead, copper and nickel found in the river water samples showed that the body of water in the Poty River is unsuitable for use in various activities. These activities in...