Optimization of electrocoagulation operating parameters applied to the recovery vehicle washing wastewater

ABSTRACT

In Brazil, about 32,700 vehicle washing stations consume 3,7 million m³ per month^-1, average of 60 L per vehicle. Consumption could be minimized if the effluent was properly treated and reused. As different types of effluents have been effectively treated by electrochemical techniques, such as electrocoagulation (EC) and electrocoagulation (EF), the main objective of this study was to develop a treatment system of carwash wastewater, by EC using electrodes aluminum. Parameters like the initial pH, applied electric current and electrolysis time were optimized by means of physical-chemical analysis and statistics. In its optimum condition, pH 5, electrical current of 3,5 A and time of 20 minutes, the system has managed to reduce by 73% the chemical oxygen demand (COD), 58% of surfactants and a minimum of 90% turbidity and total suspended solids (TSS). Besides the simple installation and operation, the technique was efficient in the recovery of this type of effluent and can be used in reuse system carwash water.

Keywords:
water reuse; aluminum electrodes; COD removal