Eletrocoagulação aplicada ao tratamento de águas residuais cosméticas

Abstract

The increase in the consumption of cosmetic products in Brazil and in the world triggers a series of environmental problems, which bring damage to ecosystems and human health. In general, the cosmetics industry uses large volumes of water to manufacture products and clean machinery, these processes are primarily responsible for the generation of cosmetic effluents. The cosmetic effluent is considered toxic and of low biodegradability, due to the presence of compounds such as: parabens, surfactants, triclosan, oils and greases and others, requiring adequate treatment before being released into the receiving water body, minimizing possible environmental damage. In this sense, the research sought to characterize the effluent from the cosmetic industry and evaluate the performance of Electrocoagulation (EC) for treating this effluent, through a batch reactor using aluminum electrodes. Treatment efficiency was evaluated through statistical analysis of the response variables: color, turbidity and chemical oxygen demand (COD) under different operating conditions of the independent variables (electrical current and treatment time). The experimental planning took place through a Rotational Central Composite Design (DCCR), composed of 12 trials, where we sought to optimize the independent variables and maximize the efficiency of the CE. Through statistical analysis, it was found that only the color and turbidity response variables were significant for the proposed model in the treatment of the analyzed effluent, thus COD was discarded from the analyses. The model showed 95% reliability for the variables electric current and treatment time to obtain the response variables. The overall desirability of the model showed optimal treatment conditions for a current intensity of 1.0 A and 10 minutes of treatment. Thus, in order to validate the proposed model based on the optimal treatment condition, the effluent was treated by EC under the conditions described in the global desirability, reaching a removal of 87.50% for color and 93.37% for turbidity, the which followed the predicted values, confirming the efficiency of EC for the treatment of the cosmetic industry.