Activation of persulfates by natural magnetic pyrrhotite for water disinfection: Efficiency, mechanisms, and stability

WATER RESEARCH

卷:112

Article

Xia, Dehua¹  Li, Yan²  Huang, Guocheng¹  Yin, Ran³  An, Taicheng⁴  Li, Guiying⁴  Zhao, Huijun^5,6  Lu, Anhuai⁷  Wong, Po Keung¹ 

[1] Chinese Univ Hong Kong, Sch Life Sci, Hong Kong, NT, Peoples R China

[2] Peking Univ, Sch Earth & Space Sci, Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China

[3] Hong Kong Univ Sci & Technol, Dept Civil & Environm Engn, Kowloon, Hong Kong, Peoples R China

[4] Guangdong Univ Technol, Sch Environm Sci & Engn, Inst Environm Hlth & Pollut Control, Guangzhou 510006, Guangdong, Peoples R China

[5] Griffith Univ, Ctr Clean Environm & Energy, Griffith Sch Environm, Griffith, NSW 4222, Australia

[6] Chinese Acad Sci, Inst Solid State Phys, Lab Nanomat & Nanostruct, Hefei 230031, Anhui, Peoples R China

[7] Cent S Univ, Sch Geosci & Info Phys, Changsha 410083, Peoples R China

关键词: Natural pyrrhotite;    Persulfate;    Sulfate radical;    Water disinfection;    Heterogeneous catalysis;   

DOI  :  10.1016/j.watres.2017.01.052

来源: Elsevier

【 摘 要 】

This study introduces natural occurring magnetic pyrrhotite (NP) as an environmentally friendly, easy available, and cost-effective alternative catalyst to activate persulfate (PS) of controlling microbial water contaminants. The E. coli K-12 inactivation kinetics observed in batch experiments was well described with first-order reaction. The optimum inactivation rate (k = 0.47 log/min) attained at a NP dose of 1 g/l. and a PS dose of 1 mM, corresponding to total inactivation of 7 log(10) cfu/mL cells within 15 min. Measured k increased > 2-fold when temperature increased from 20 to 50 degrees C; and > 4-fold when pH decreased from 9 to 3. Aerobic conditions were more beneficial to cell inactivation than anaerobic conditions due to more reactive oxygen species (ROS) generated. ROS responsible for the inactivation were identified to be (SO4-)-S-center dot > (OH)-O-center dot > H2O2 based on a positive scavenging test and in situ ROS determinationin situ characterization suggested that PS effectively bind to NP surface was likely to form charge transfer complex ( fe(II)center dot center dot center dot O3SO-OSO3-), which mediated ROS generation and E. coli K-12 oxidation. The increased cell-envelope lesions consequently aggravated intracellular protein depletion and genome damage to cause definite bacterial death. The NP still maintained good physiochemical structure and stable activity even after 4 cycle. Moreover, NP/PS system also exhibited good E. colt K-12 inactivation efficiency in authentic water matrices like surface water and effluents of secondary wastewater. (C) 2017 Elsevier Ltd. All rights reserved.

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