Application of natural hematite as catalyst in heterogeneous photo-Fenton like process for 2,4-dichlorophenol degradation

This work investigates the degradation of 2,4-dichlorophenol (2,4-DCP) through the combination of hematite and UV light for the activation of sodium percarbonate (SPC) in a heterogeneous photo-Fenton like (HPF) process. The hematite was fully characterised and the effects of different reaction parameters such as pH, doses of hematite and SPC, 2,4-DCP initial concentration, and the presence of co-existing anions were investigated. Under the optimised conditions (pH = 3.0, [Hematite]₀ = 300.0 mg L⁻¹, [SPC]₀ = 500.0 mg L⁻¹), the degradation of 2,4-DCP (50.0 mg L⁻¹) was 99.88 ± 0.05 %. Quenching experiments demonstrated the participation of ¹O₂, O₂⁻, CO₃⁻, and OH radicals in the degradation of 2,4-DCP, with the dominance of OH radicals (82.39 %). Furthermore, the degradation of 2,4-DCP was effectively retarded by the presence of Cl⁻, NO₃⁻, CO₃²⁻, and PO₄³⁻ anions in the solution. Overall, the HPF process with hematite can be proposed as an effective and promising approach for the degradation of 2,4-DCP from the waste stream and can be used for the decontamination of other organic compounds due to its stability and feasibility.