Reduced effect of bromide on the genotoxicity in secondary effluent of a municipal wastewater treatment plant during chlorination.
Chlorination of wastewater can form genotoxic, mutagenic, and/or carcinogenic disinfection byproduct (DBPs). In this study, the effect of bromide on genotoxicity in secondary effluent of a municipal wastewater treatment plant during chlorination was evaluated by the SOS/umu test. The presence of bromide notably decreased the genotoxicity in secondary effluent during chlorination, especially under conditions of high ammonia concentration. Bromide significantly decreased the concentration of ofloxacin, a genotoxic chemical in secondary effluent, during chlorination with high concentration of ammonia, while genotoxic DBPs formation of humic acid and aromatic amino acids associated with bromide limitedly contributed to the changes of genotoxicity in secondary effluent under the conditions of this study. By fractionating dissolved organic matter (DOM) in the secondary effluent into different fractions, the fractions containing hydrophilic substances (HIS) and hydrophobic acids (HOA) contributed to the decrease in genotoxicity induced by bromide. Chlorination of HOA without bromide increased genotoxicity, while the addition of bromide decreased genotoxicity.
Wu
Qian-Yuan
QY
Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, PR China.
Li
Yi
Y
Hu
Hong-Ying
HY
Sun
Ying-Xue
YX
Zhao
Feng-Yun
FY
D001965:Bromides / Q000032:analysis* / Q000737:chemistry*; D002947:Cities; D004202:Disinfectants / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D054879:Halogenation; D009153:Mutagens; D015242:Ofloxacin / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D001965:Bromides; D004202:Disinfectants; D009153:Mutagens; D014874:Water Pollutants, Chemical; D015242:Ofloxacin