Efficient degradation of organic pollutants with ferrous hydroxide colloids as heterogeneous Fenton-like activator of hydrogen peroxide

摘要

Ferrous hydroxide colloids were prepared and characterized as an activator of H_2O_2 for decomposing organic pollutants, such as Rhodamine B, sulfamonomethoxine (SMM) and 4-nitrophenol (4-NP). As major reactive oxygen species, hydroxyl radicals were confirmed to be generated in the activation of H_2O_2 by using fluorescent probe technique and electron spin resonance technique. The highly-dispersed colloidal nanoparticles with large specific surface area combined the merits of both homogeneous and heterogeneous activator, leading to fast degradation of organic contaminants. Almost complete decolor-ization of added RhB (0.02 Mm), along with a removal of 64.3% of total organic carbon, was achieved within only 1 min by adding 0.30 Mm ferrous hydroxide colloids and 1.20 Mm H_2O_2 at Ph 7.0. Based on the contributions from the redox activation and the caged activation, a new mechanism was proposed to explain the enhancing effect of the colloids.