Avaliação da qualidade do Rio São Lourenço, SP, sob influência de estações de tratamento de água e estações de tratamento de esgoto / ENVIRONMENTAL QUALITY IN AREA OF INFLUENCE OF MUD OF STATIONS FOR TREATMENT OF WATER AND SEWAGE

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

For a long time, there was a neglect to water resources, both by society as by the authorities. The rapid increase of population, causing disorderly occupations, was ignored by the public sectors and the society itself, resulting in environmental degradation. Ecotoxicological tests are essential to environmental assessment, together with chemical and biological evaluation. Currently, there are more than 7,500 water treatment plants (WTP) conventional in Brazil. It is estimated that around 2,000 tonnes of solids (sludge generated after treatment) in Brazilian waters are discharged without any treatment. The objective of this work was the application of the triad of quality of the sediment, in addition to chemical and ecotoxicological evaluation of the water of the St. Lawrence River, as a subsidy for the study on the influence of the disposal of water treatment plants (WTP) and Sewage (SWT) of the municipalities of São Lourenço da Serra e Juquitiba (SP). The São Lourenço River, in addition to supplying the city of São Lourenço da Serra and receive all the pollution load of St. Lawrence and the Sierra e Juquitiba is one of the main tributaries of the Rio Juquiá, which is part of Watersheds Ribeira Valley. Seven samples were taken during the years 2004, 2005 and 2006, 12 points in the St. Lawrence River, the upstream and downstream of the stations, which included samples of water, for analysis of abiotic parameters and ecotoxicological and sediment for evaluation parameters Ecotoxicological. In 2006 the collection of sediment samples included for evaluation of abiotic and biological parameters, data used for the implementation of the Sediment Quality Triad. The species used in different trophic levels in ecotoxicity testing, mainly indigenous organizations, as an important tool to assess the tropical environments. In the evaluation of toxicity, were tested for acute and chronic toxicity of water with Daphnia similis and Daphnia laevis, Ceriodaphnia silvestrii and Ceriodaphnia dubia, and sediment to aquatic organisms: Ceriodaphnia silvestrii, Hyalella azteca and Chironomus xanthus. In acute ecotoxicological tests were used for statistical analysis of the test TUKEY (TOXTAT 3.4) and for chronic toxicity testing of the method proposed by EPA (2002). The results of September 2006 were included and submitted to multivariate analysis. The achievements of the San Lorenzo Serra showed negative responses on the benthic community resident in the place. The critical points in ecotoxicological assessment of sediment downstream were downstream of WTP and SWT, which was not possible the correlation of these results with the chemical assessment. Samples of water had ecotoxicity points downstream of WTP and SWT. The results indicate that the site is influenced by human actions beyond the disposal of WTP and SWT. In Juquitiba, WTP was observed influence on water quality. In assessing the structure of the benthic community, the family Tubificidae was present and dominant at every point, characteristic of environmental impact. In the evaluation of chemical contamination of water, were found high concentrations of Al and Fe, which are vii not connected to sewage stations and are natural features of the Sao Paulo. These results show that the quality of water and sediment of the St. Lawrence River at this location is committed beyond the influence of environmental disposal of WTP and SWT. There is need for greater environmental control in the area, since this is an area of environmental preservation.

ASSUNTO(S)

tqs ecotoxicologia sedimento sedimento organismos bentônicos estações de tratamento estações de tratamento organismos bentônicos tqs ecotoxicologia

ACESSO AO ARTIGO

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