Xie Weiping, Dong Wei, Kong Deyang, Ji Yuefei, Lu Junhe, Yin Xiaoming
Station of Environmental Monitoring of Yixing, Yixing, Jiangsu Province 214201, China.
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China.
Chemosphere. 2016 Jul;154:613-619. doi: 10.1016/j.chemosphere.2016.04.025. Epub 2016 Apr 18.
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.
通过过一硫酸盐（PMS）和过硫酸盐（PS）活化产生的硫酸根自由基（SO4(-)）具有高氧化性，可用于降解各种有机污染物。本研究旨在调查在卤化物和天然有机物（NOM）存在的情况下，Co(2+)活化PMS过程中卤代副产物的形成情况。结果表明，在存在Cl(-)的情况下未检测到卤代副产物，而当最初存在2mg/L NOM、0.1mM Br(-)、1.0mM PMS和5μL Co(2+)时，120小时后发现有189μg/L的溴仿和100.7μg/L的二溴乙酸（DBAA）。这些产物被称为消毒副产物（DBPs），因为它们是在水消毒过程中形成的。在没有Co(2+)的情况下，DBPs的形成更为显著。数据表明，PMS和SO4(-)都可以将Br(-)转化为活性溴物种，这些活性溴物种与NOM反应形成卤代副产物。Co(2+)-PMS系统中较少的DBP形成是由于SO4(-)对DBPs的进一步破坏。在同时存在Cl(-)和Br(-)的情况下，检测到更多的DBP物种，包括氯化物。然而，一般来说，产生的溴化物种比氯化物种更多。当总卤化物保持恒定时，总DBP产率随着Cl(-)含量的增加而降低。这是为数不多的证明Co(2+)/PMS反应系统中卤代DBPs形成的研究之一，在基于SO4(-)的氧化技术应用中应予以考虑。
