Formation of halogenated disinfection by-products in cobalt-catalyzed peroxymonosulfate oxidation processes in the presence of halides.
Sulfate radicals (SO4(-)) generated by activation of peroxymonosulfate (PMS) and persulfate (PS) are highly oxidative and applied to degrade various organic pollutants. This research was designed to investigate formation of halogenated by-products in Co(2+) activated PMS process in the presence of halides and natural organic matter (NOM). It was revealed that no halogenated by-products were detected in the presence of Cl(-) while 189 μg/L bromoform and 100.7 μg/L dibromoacetic acid (DBAA) were found after 120 h when 2 mg/L NOM, 0.1 mM Br(-), 1.0 mM PMS, and 5 μL Co(2+) were present initially. These products are known as disinfection by-products (DBPs) since they are formed in water disinfection processes. Formation of DBPs was even more significant in the absence of Co(2+). The data indicate that both PMS and SO4(-) can transform Br(-) to reactive bromine species which react with NOM to form halogenated by-products. Less DBP formation in Co(2+)-PMS systems was due to the further destruction of DBPs by SO4(-). More DBPs species including chlorinated ones were detected in the presence of both Cl(-) and Br(-). However, more brominated species produced than chlorinate ones generally. The total DBP yield decreased with the increase of Cl(-) content when total halides kept constant. This is one of the few studies that demonstrate the formation of halogenated DBPs in Co(2+)/PMS reaction systems, which should be taken into consideration in the application of SO4(-) based oxidation technologies.
Station of Environmental Monitoring of Yixing, Yixing, Jiangsu Province 214201, China.
Weiping
W
Xie
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China.
Wei
W
Dong
Nanjing Institute of Environmental Science, Ministry of Environmental Protection of PRC, Nanjing 210042, China.
Deyang
D
Kong
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China.
Yuefei
Y
Ji
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: jhlu@njau.edu.cn.
Junhe
J
Lu
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China.
Xiaoming
X
Yin
D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D054879:Halogenation; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
D001965:Bromides; D010545:Peroxides; D013431:Sulfates; D014874:Water Pollutants, Chemical; C069025:sulfate radical; C038288:peroxymonosulfate; D003035:Cobalt
Bromide; Chloride; Disinfection by-products; Peroxymonosulfate; Sulfate radical