Avaliação do impacto em corpos d’água devido ao lançamento de resíduos de uma estação de tratamento de água de Juiz de Fora - MG

Abstract

The water from filter washing and decanter sludge are waste material coming from Water Treatment Stations (WTS) during the steps from water clarification. These residues are composed of organic and inorganic matter, chemical products, microorganisms, soil particles and water and, therefore, require appropriate treatment before being disposed in nature, because they can contaminate and pollute the environment. Most Brazilian WTS still discard their untreated wastewater into bodies of water silting up bodies of water, changing the quality of water, increasing metal and solid concentration. To determine the degree of impact from sludge and filter washing water and to choose appropriate mitigation measures, knowing these residues characteristics is mandatory, and they vary according to the type of treatment in the WTS, the chemical products used and the properties of the raw water. Through of physico-chemical parameters analysis and comparisons with existing laws, a characterization of filter washing water and decanter sludge of a WTS in the municipality of Juiz de Fora was performed and also an evaluation of water quality throughout the receiver body of these residues. The results showed that the discard in nature without prior treatment of the wastewaters from Water Treatment Stations can cause impact on water bodies, increasing significantly the concentration of total solids.