Ferrioxalate-induced solar photo-Fenton treatment of natural rubber latex wastewaters

This study evaluated a ferrioxalate-induced solar photo-Fenton process for natural rubber latex wastewater treatment. The reaction was carried out in a laboratory-scale solar photo-Fenton plug flow baffle reactor. An optimization study was performed using a central composite experimental design including the following variables: pH, initial concentrations of H2O2, Fe2+, and oxalic acid. The photocatalytic degradation efficiency was determined by the analysis of chemical oxygen demand (COD) removal. Under the optimum conditions of pH = 4, Fe2+ = 1.3 g/L, oxalic acid = 2.25 g/L, H2O2 = 82.5 g/L, and solar irradiation time of 6 hours, the COD removal efficiency was 99%. Treatment of latex wastewater by ferrioxalate-induced solar photo-Fenton process increased biodegradability ratio from 0.36 to 0.7 in 2 hours. The overall cost of ferrioxalate-induced solar photo-Fenton oxidation for the treatment of 5 m3 of latex wastewater per day was estimated to be US$85/m3.