Efficient transformation of DDTs with Persulfate Activation by Zero-valent Iron Nanoparticles: A Mechanistic Study

Changyin Zhu; Guodong Fang; Dionysios D Dionysiou; Cun Liu; Juan Gao; Wenxiu Qin; Dongmei Zhou

doi:10.1016/j.jhazmat.2016.05.040

Efficient transformation of DDTs with Persulfate Activation by Zero-valent Iron Nanoparticles: A Mechanistic Study

J Hazard Mater. 2016 Oct 5:316:232-41. doi: 10.1016/j.jhazmat.2016.05.040. Epub 2016 May 13.

Authors

Changyin Zhu¹, Guodong Fang², Dionysios D Dionysiou³, Cun Liu⁴, Juan Gao⁴, Wenxiu Qin¹, Dongmei Zhou⁵

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
² Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China. Electronic address: gdfang@issas.ac.cn.
³ Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0071, USA.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
⁵ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China. Electronic address: dmzhou@issas.ac.cn.

PMID: 27236432
DOI: 10.1016/j.jhazmat.2016.05.040

Abstract

In this study, persulfate (PS) activation by nano-Fe(0) was used to degrade dichlorodiphenyltrichloroethane (DDT), and the mechanism of this process was elucidated with EPR, GC-MS and free-radical quenching studies. It was found that DDT was degraded efficiently in PS/nano-Fe(0), and GC-MS analysis showed that benzoic acid, benzyl alcohol, dichlorobenzophenone and 2,2-bis(p-chlorophenyl)-ethane were the dominant products of DDT degradation, while only dechlorination products (DDD and DDE) were observed in nano-Fe(0) without persulfate. EPR results showed that persulfate activation by nano-Fe(0) led to the production of more sulfate radicals and hydroxyl radicals, which accounted for DDT degradation. But the free radical quenching studies suggested that the addition of ethanol to PS/nano-Fe(0) favored the reductive dechlorination of DDT, which was ascribed that the formed ethanol radical (CH(CH3)OH) enhanced the reductive dechlorination of DDT. Furthermore, the nano-Fe(0) loading not only affected the degradation efficiency of DDT, but also influenced the intermediate product distribution of DDT degradation in the PS/nano-Fe(0) process.

Keywords: Activation; DDT degradation; Free radicals; Nano-Fe(0); Persulfate.

Publication types

Research Support, Non-U.S. Gov't