Enhanced Fenton-like degradation of refractory organic compounds by surface complex formation of LaFeO(3) and H(2)O(2).

Nanoscale LaFeO(3) was prepared via sol-gel method and characterized by XRD, FTIR and N2 adsorption/desorption experiment. The results indicated that, LaFeO(3) had a typical perovskite structure with a BET area of 8.5m(2)/g. LaFeO(3) exhibited excellent Fenton activity and stability for the degradation of pharmaceuticals and herbicides in water, as demonstrated with sulfamethoxazole, phenazone, phenytoin, acyclovir and 2,4-dichlorophenoxyacetic acid, 2-chlorophenol. Among them, sulfamethoxazole (SMX) could be completely removed in LaFeO(3)-H(2)O(2) system after reaction for 120 min at neutral pH. Based on the ATR-FTIR analysis, the surface complex of LaFeO(3) and H(2)O(2). was formed, which was important and essential for the enhanced Fenton reaction by accelerating the cycle of Fe(3+)/Fe(2+). Hence, more OH and O(2)(-)/HO(2)(-) were then produced in LaFeO(3)-H(2)O(2) system, resulting in more efficient removal of refractory organic compounds. Based on the surface interaction of LaFeO(3) and H(2)O(2), a heterogeneous Fenton reaction mechanism was proposed.