Utilização de eletrodos de sacrifício de ferro na eletrofloculação do efluente de indústria cosmética: avaliação da eficiência de tratamento

Abstract

The industrial sector, in general, needs water to carry out its activities. In cosmetic industries, it is one of the essential raw materials for production. As a result of the production process solid and liquid residues are generated, which need adequate treatment in order to avoid the pollution of the water bodies. This study aimed to apply electrofloculation (EF) using iron (Fe) as a sacrificial electrode in a cosmetic industry effluent. The efficiency of the technique was evaluated through the analysis of the variables COD, turbidity, apparent color and absorbance (350 nm), under different conditions of electric current intensity and treatment time. The experimental design was conducted according to the Central Compound Rotational Design (CCRD), composed of 12 trials, in order to optimize the independent variables mentioned above and to maximize the efficiency of the EF for the dependent variables. It was verified that the CCRD used, as well as the statistical analysis, affirmed with 95 % reliability the significance of the variables current and time of treatment to obtain the response variables, represented by the percentage of removal of COD, turbidity, apparent color and absorbance ( 350 nm). In the determination of optimized conditions for the independent variables, a current of 2.5 A with a treatment time of 29.54 min was obtained. From the optimized condition the validation of the treatment of PE was achieved, with a 61.35 % removal for COD, 92.31 % for turbidity, 93.69 % apparent color and 92.69 % absorbance (350 nm), which followed the trend predicted by the model, confirming that EF is an efficient technique.