Ozonation catalyzed by iron silicate for the degradation of o-chloronitrobenzene in drinking water

This paper aimed to reveal the effectiveness and the mechanism of catalytic ozonation in the presence of iron silicate for the degradation of o-chloronitrobenzene (oCNB). Experimental results show that catalytic ozonation in the presence of iron silicate could substantially enhance oCNB removal efficiency compared with ozonation alone, and that the adsorption of oCNB on the iron silicate surface had no significant effect on the degradation of oCNB. The results of a hydroxyl radical scavenger experiment using spin-trapping/EPR technology to identify hydroxyl radicals (•OH) confirm that •OH were the main active species in the removal of oCNB during the ozonation process catalyzed by iron silicate. The catalytic activity of the iron silicate was related to a highly hydroxylated surface. It was confirmed that the surface hydroxyl groups on the iron silicate were the reaction sites between ozone and oCNB.