Treatment of atrazine-contaminated wastewater via heterogeneous Fenton and heterogeneous photo-Fenton processes

This study corroborated the viability of heterogeneous Fenton and heterogeneous photo-Fenton process for the degradation of atrazine from aqueous solution. Nano-scale iron manganese binary oxide supported zeolite (NIMZ) was synthesized and was used as a catalyst to degrade atrazine. The influence of numerous factors like pH, H₂O₂ dosage, and catalyst dosage on atrazine degradation was investigated. Under the operating parameters of pH 3, 0.02 M H₂O₂, and 200 mg/L catalyst, the heterogeneous Fenton system reached its highest atrazine degradation efficiency of 58.15%. Nonetheless, the atrazine elimination achieved through the heterogeneous Fenton method was relatively modest. Thus, to enhance the atrazine degradation efficiency, heterogeneous photo-Fenton method was employed to treat atrazine concentration of 50 µg/L. The experimentally determined optimal pH, H₂O₂ dosage and catalyst dosage in the heterogeneous photo-Fenton process were 3, 0.02 M and 250 mg/L, respectively. A degradation efficiency of 76.26% was recorded with the heterogeneous photo-Fenton process, exceeding the conventional heterogeneous Fenton process (58.15%) by 18.11%. Quenching studies revealed that effectiveness of heterogeneous photo-Fenton process was majorly owing to large number of hydroxyl radicals generated because of catalytic decomposition of H₂O₂ by NIMZ and photo decomposition of H₂O₂ by irradiation of UV light.