Surfactant aided electrocoagulation/flotation using punched electrodes for the remediation of salicylic acid from wastewater

Abstract

Performance of a batch electrocoagulation/floatation (ECF) setup using punched aluminium electrodes for the remediation of salicylic acid in the presence of cetyl-trimethyl ammonium bromide (CTAB) surfactant is evaluated in this research. The operational parameters of ECF technology were optimized in this research and based on the optimized operating conditions with electrolysis time of 50 min, electrode gap of 2 cm, electrolyte concentration of 0.6 g/L, pH of 7.2, a current density of 2.25 mA/cm2, and 20 mg/L of CTAB dose, about 92.1 ± 2.5% of salicylic acid removal was attained corresponding to an initial salicylic acid concentration of 50 mg/L. The salicylic acid degradation in ECF was observed to follow first−order−rate kinetics. The electrode corrosion and sludge generation were also evaluated. After the ECF-based treatment, a considerable reduction in phytotoxicity was observed, which was suitable for the germination of the Vigna radiata. About 2 mM of green fuel H2 gas was also produced during the treatment. The sludge generated during ECF was reduced nearly by 2−folds when cationic surfactant CTAB was added to the electrolyte. Moreover, the energy consumption of 0.328 kWh and treatment cost of 0.21 US$ (16.72 INR) were observed for the treatment of per m3 of salicylic contaminated wastewater. Treatment efficiency of salicylic acid in a real municipal wastewater matrix was about 65 ± 3.4% at optimum operating conditions, contributing to 47% of total organic carbon removal. Thus, ECF process was found to be effective in removal of salicylic acid from contaminated water.