Pré-Tratamento do Efluente Urbano de um Lava Jato pela Técnica da Eletrocoagulação com o Uso de Diferentes Eletrólitos de Suporte

Abstract

The exacerbated consumption of durable and non-durable goods generates a large pollution load in urban centers, negatively impacting water treatment centers due to the immense demand. In this context, urban projects such as car washes, which have their effluents characterized by the presence of surfactants, oils and greases, heavy metals, total suspended solids, which are substances that have a significant polluting potential, can have their effluent pre-treated through of electrocoagulation to minimize the polluting load, enabling the attenuation of subsequent multiprocesses of treatment. In this perspective, this work sought to carry out the physical-chemical treatment in an effluent from a car wash, using the electrocoagulation method. For this purpose, copper electrodes were used in addition to the addition of different salts as support electrolytes, among which sodium hydroxide (NaOH), sodium bicarbonate (NaHCO3), free aluminum sulfate (Al2(SO4)3) and sodium carbonate (Na2CO3). As a result, the electrochemically treated effluent using the free aluminum sulfate support electrolyte showed promising results for the pre-treatment process of this type of effluent. In this sense, the efficiencies in removing apparent color and turbidity were respectively 89.18% and 76.62% for a treatment process time of 5 minutes with 12 V. The pre-treated effluent still had a final pH of 5.28, in accordance with what determines the rules of CONAMA nº 430/2011, being, therefore, an excellent option for the pre-treatment, mainly for effluents characterized by the presence of grease.