Activation of persulfate by Fe-bearing materials for remediation of diesel/biodiesel-contaminated soils and phenol-contaminated water

Abstract

In this research, batch experiments were performed to examine the remediation of organic pollutants using modified persulfate (PS) systems. Zero-valent iron [Fe(0)] and other iron-bearing materials were applied to activate the PS systems for treating diesel and biodiesel contaminated soils and phenol-contaminated water. After 12 h, Fe(0)-PS, 82.6% and 85.3% of diesel and biodiesel in soils were removed, respectively. The optimal molar ratios of Fe(0)-to- PS and FeS-to-PS were 68.6:1 and 43.6:1, respectively. Biochar (BC) was proposed to combine with Fe(0) to enhance the oxidation of phenol by PS. BC could accelerate the oxidation of phenol by Fe(0)-activated PS probably due to surface functional groups and electron distribution in biochar. Controlling factors including pH, PS concentration, and various black carbon materials were also examined. Complete degradation of phenol was achieved in 330 min with 3000 mg of Fe(0), 2500 mg/L of PS, and 200 mg of biochar at pH 7. Our results suggest that the oxidation by PS activated with iron-bearing materials and biochar may be a viable option to treat organic pollutants in natural environments.