ZUOHui-wen,JINXin,JINPeng-kang.Formation Characteristics of Bromate Disinfection By-product in Hybrid Ozonation-Coagulation Process[J].China Water & Wastewater,2024,40(21):73-80.
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Formation Characteristics of Bromate Disinfection By-product in Hybrid Ozonation-Coagulation Process

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第40卷 Number: 第21期 Page: 73-80 Column: Date of publication: 2024-11-01
Author(s):
ZUO　Hui-wen1; 2;  JIN　Xin3;  JIN　Peng-kang1; 3
（1. School of Environmental and Municipal Engineering， Xi’an University of Architecture and Technology， Xi’an 710055， China； 2. Chengdu Municipal Engineering Design & Research Institute Co. Ltd.， Chengdu 610023， China； 3. School of Human Settlements and Civil Engineering， Xi’an Jiaotong University， Xi’an 710049， China）
Keywords:
hybrid ozonation-coagulation (HOC) process;  effluent from secondary treatment process;  bromate;  disinfection by-product;  ozonation
Abstract:
To control the formation of bromate (BrO3-), a disinfection by-product in the secondary effluent from the wastewater treatment plant, the characteristics of BrO3-formation in the hybrid ozonation-coagulation (HOC) process under diverse reaction conditions were investigated, the optimal conditions for controlling BrO3- formation were determined, and the formation pathway of BrO3- was revealed. The HOC process effectively eliminated the residual organic matters in the secondary effluent. However, it generated BrO3-, thereby leading to an increase in acute toxicity. The elevation of pH and the augmentation of ozone dosage facilitated the formation of BrO3-. The quantity of BrO3- generated when aluminum chloride was employed as the coagulant was marginally higher than that when aluminum sulfate was utilized as the coagulant, and organic matters could impede the formation of BrO3- by regulating the intermediate product hypobromous acid. Based on the aforesaid results, the optimal reaction conditions of HOC were determined as follows: pH was 7, the dosage of ozone was 1.0 mg/mg（calculated by TOC), the dosage of aluminum chloride was 15 mg/L (calculated by Al), and the reaction time was 8 min. Under these circumstances, the removal efficiency of organic matter could be maintained above 30%, and the yield of BrO3- was less than 10 μg/L, meeting the limit specified in Standards for Drinking Water Quality (GB 5749-2006). The formation pathway of BrO3- encompassed direct oxidation by ozone and indirect oxidation by hydroxyl radical (·OH), among which ozonation constituted the primary pathway, accounting for up to 90%.
Last Update: 2024-11-01