Effective removal of chlorinated organic pollutants by bimetallic iron-nickel sulfide activation of peroxydisulfate

Abstract

Chlorinated organic pollutants (COPs) have caused serious contaminants in soil and groundwater, hence developing methods to remove these pollutants is necessary and urgent. By a simple hydrothermal method, we synthesized the bimetallic iron-nickel sulfide (FeNiS) particles which exhibited excellent catalytic property of COPs removal. FeNiS was chosen as the peroxydisulfate (PDS) activator to removal COPs including 4-chlorophenol (4-CP), 1,4-dichlorophenol (1,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). The results show that FeNiS can efficiently activate PDS to produce sulfate radical (SO4−) which plays major role in the oxidative dechlorination and degradation due to its strong oxidizing property and the ability of producing hydroxyl radicals (OH) in the alkaline condition. Meanwhile, the Cl− abscised from COPs during the dechlorination can turn into the chlorine radicals and enhance the degradation and cause further mineralization of intermediate products. This bimetallic FeNiS catalyst is a promising PDS activator for removal of chlorinated organics.