Avaliação de sistema de tratamento de efluentes de lavagem de uma oficina mecânica por eletroflotação para reúso

Abstract

The amount of water used in washing stations in Brazil is about 3.7 million m³/month and is not usually reused or treated before disposal. Concern over water scarcity and pollution has been increasing over time. Effluent treatment for reuse in industries is a solution found to reduce the pollutant load that is produced. In this context, electroflotation has been gaining strength among the others methods. In this context, the objective of this study is to evaluate the use of electroflotation to provide the reuse of washing water from a car wash. Thus, an electroflotation tank with a useful volume of three liters, with aluminum electrodes, arranged in monopolar in parallel with inversion of polarity was used. The tests were done with a treatment time of 10, 20 and 30 minutes. A post-treatment with activated charcoal was also evaluated. In the samples, this parameters were analyzed: pH, color, turbidity, total, suspend, sedimented and dissolved solids, electrical conductivity, chemical oxygen demand, surfactants, oils and greases concentration and aluminum. For the treatment time of 20 minutes with post-treatment, which was the most appropriate, the results obtained were 61% removal of chemical oxygen demand, 93% turbidity, 80% surfactants, 27% total dissolved solids, 65% total suspended solids and 40% total solids. Besides the partial removal of oils and greases, sedimentable solids and the reduction of the effluent color. Through the results, it was verified that it is possible to use electroflotation to reuse the effluent in the company, although it is necessary to reduce the pH and turbidity for the reuse, and further studies are necessary to prove it.(sic)