Natural magnetic pyrrhotite as a high-Efficient persulfate activator for micropollutants degradation: Radicals identification and toxicity evaluation

Dehua Xia; Ran Yin; Jianliang Sun; Taicheng An; Guiying Li; Wanjun Wang; Huijun Zhao; Po Keung Wong

doi:10.1016/j.jhazmat.2017.07.029

Natural magnetic pyrrhotite as a high-Efficient persulfate activator for micropollutants degradation: Radicals identification and toxicity evaluation

J Hazard Mater. 2017 Oct 15:340:435-444. doi: 10.1016/j.jhazmat.2017.07.029. Epub 2017 Jul 20.

Authors

Dehua Xia¹, Ran Yin², Jianliang Sun², Taicheng An³, Guiying Li⁴, Wanjun Wang⁴, Huijun Zhao⁵, Po Keung Wong⁶

Affiliations

¹ School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
² Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
³ Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, Guangdong, China. Electronic address: antc99@gdut.edu.cn.
⁴ Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, Guangdong, China.
⁵ Centre for Clean Environment and Energy, Griffith Scholl of Environment, Griffith University, Queensland 4222, Australia; Laboratory of Nanomaterials and Nanostructures, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
⁶ School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China. Electronic address: pkwong@cuhk.edu.hk.

PMID: 28755551
DOI: 10.1016/j.jhazmat.2017.07.029

Abstract

This study discusses the SO₄^- based process mediated by natural magnetic pyrrhotite (NP) for the degradation of refractory organic micropollutants. Complete degradation of 20μM phenol in distilled water (DW) was obtained within 20min using NP/PS (persulfate) system. Electron paramagnetic resonance spectra indicated aerobic and acidic conditions favored the generation of both SO₄^- and OH species, but only OH signal was survived at alkaline condition. The leaked Fe²⁺ and Fe(II) of NP collectively work to activate PS and generate surface and bulk SO₄^- and OH simultaneously. The identified intermediates indicate the transformation of benzene ring is the key step for phenol degradation by NP/PS system. Moreover, phenol degradation was greatly inhibited in surface water (SW, 29%) and wastewater (WW, 1%), but 25.9% and 17.5% of TOC removal were obtained in the SW and WW during NP/PS treatment, respectively. Additionally, the acute toxicity tests for NP/PS process exhibited a fluctuating trend depending on the water matrix, while the genotoxic activity analysis indicated that the treated phenol solutions were not genotoxic but cytotoxic. Overall, this study provides a solution to abate refractory organic micropollutants in water systems.

Keywords: Eco-toxicity; Natural pyrrhotite; Persulfate; Phenol degradation; Sulfate radical.

MeSH terms

Aliivibrio fischeri / drug effects
Aliivibrio fischeri / metabolism
Hydroxyl Radical / chemistry
Iron / chemistry*
Magnetic Phenomena
Phenol / chemistry*
Phenol / toxicity
Sulfates / chemistry
Sulfides / chemistry*
Water Pollutants, Chemical / chemistry*
Water Pollutants, Chemical / toxicity
Water Purification / methods*

Substances

Sulfates
Sulfides
Water Pollutants, Chemical
Hydroxyl Radical
Phenol
Iron