Hai Chen, Zhonglei Zhang, Mingbao Feng
Apr 1, 2017
Citations
2
Influential Citations
158
Citations
Quality indicators
Journal
Chemical Engineering Journal
Abstract
Abstract In this study, mackinawite (FeS) was prepared and used as the heterogeneous catalyst to activate persulfate (PS) for 2,4-dichlorophenoxyacetic acid (2,4-D) degradation, and impact factors including initial pH, PS concentration, FeS dosage, reaction temperature and inorganic anions (Cl − , NO 3 − , and HCO 3 − ), were investigated. The results showed that 2,4-D could be efficiently degraded and mineralized by FeS/PS system. Acidic pH would accelerate 2,4-D degradation, whereas neutral and alkaline conditions showed negative effects. The degradation efficiency of 2,4-D was improved with increasing FeS dosage, PS concentration and reaction temperature. Furthermore, inorganic anions exerted different effects on 2,4-D degradation. The quenching experiments indicated that though both sulfate radicals (SO 4 − ) and hydroxyl radicals (HO ) were responsible for 2,4-D degradation, HO played a more important role. Based on the quenching tests and electron paramagnetic resonance (EPR) analysis, the possible mechanism of 2,4-D oxidation in FeS/PS system was proposed. Additionally, the reusability tests revealed that, although FeS had a short time of deactivation after first use, it still maintained satisfactory catalytic activity in five consecutive 2,4-D degradation experiments. The transformation intermediates were identified by a gas chromatography mass spectrometry (GC–MS), and the possible reaction pathways were proposed based on the measured results. The method of activating PS with FeS may offer great benefits for the application of iron-containing mineral in remediation of herbicide-contaminated water.