LIMian,QINLang,YANGDan,et al.Ultraviolet for Degradation of Iohexol and Its Iodinated Trihalomethanes Formation Characteristics[J].China Water & Wastewater,2024,40(9):91-97.
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Ultraviolet for Degradation of Iohexol and Its Iodinated Trihalomethanes Formation Characteristics

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第40卷 Number: 第9期 Page: 91-97 Column: Date of publication: 2024-05-01
Author(s):
LI　Mian1;  QIN　Lang2;  YANG　Dan1;  ZHANG　Tian-yang2;  HU　Chen-yan3;  XU　Bin2
（1. College of Biological and Environmental Engineering， Guiyang University， Guiyang 550005， China； 2. College of Environmental Science and Engineering， Tongji University， Shanghai 200092， China； 3. College of Environmental and Chemical Engineering， Shanghai University of Electric Power， Shanghai 201306， China）
Keywords:
ultraviolet;  iohexol;  iodinated disinfection by-products;  chlorination
Abstract:
This paper investigated the performance of ultraviolet (UV) for degradation of iohexol and the characteristics of iodinated trihalomethanes (I-THMs) formation, explored the distribution of disinfection by-products (DBPs) as well as the effects of UV intensity, pH and Br- concentration on the degradation of iohexol and I-THMs formation, and revealed the changes of DBPs in actual water bodies. The degradation rate of iohexol was positively correlated with UV intensity and negatively correlated with the complexity of raw water composition, and was little affected by pH and Br- concentration. The DBPs produced in the system included chloroform (CF), chloral hydrate (CH), dichloroacetonitrile (DCAN), trichloronitromethane (TCNM) and three kinds of I-THMs (CHCl2I、CHClI2、CHI3) among which CF concentration was the highest, followed by CHCl2I. The I-THMs production initially increased and then decreased with the increase of UV intensity and pH, and reached the maximum value when UV intensity was 2 670 mJ/cm2 and pH was 7. With the increase of Br- concentration, the concentration of CHI3 increased continuously, and the proportion of three bromine-containing I-THMs (CHBrI2, CHBr2I and CHClBrI) gradually increased, whereas the proportion of two chlorine-containing I-THMs (CHCl2I and CHClI2) gradually decreased. The No.2 raw water sample with more complex water composition produced a higher concentration of I-THMs than the No.1 raw water sample. Compared with pure water, three bromine-containing I-THMs were generated in both raw water samples, but the three bromine-free I-THMs (CHCl2I, CHClI2 and CHI3) still accounted for the main part of the total I-THMs, and their concentrations were higher than that generated under the background of pure water. Natural organic matter (NOM) in water promoted the formation of I-THMs.
Last Update: 2024-05-01