臭氧混凝耦合工艺的溴酸盐消毒副产物生成特性  

Formation Characteristics of Bromate Disinfection By-product in HybridOzonation-Coagulation Process

作　　者：左绘雯 金鑫[3] 金鹏康[1,3] ZUO Hui-wen;JIN Xin;JIN Peng-kang(School of Environmental and Municipal Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Chengdu Municipal Engineering Design&Research Institute Co.Ltd.,Chengdu 610023,China;School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西西安710055 [2]成都市市政工程设计研究院有限公司,四川成都610023 [3]西安交通大学人居环境与建筑工程学院,陕西西安710049

出　　处：《中国给水排水》2024年第21期73-80,共8页China Water & Wastewater

基　　金：国家自然科学基金资助项目(52070151、52230001、52170052);陕西省重点研发计划项目(2021ZDLSF05-06)。

摘　　要：为了控制臭氧混凝耦合(HOC)工艺在处理污水厂二级出水过程中消毒副产物溴酸盐(BrO_(3)-)的生成,考察了HOC工艺在不同反应条件下的BrO_(3)-生成特性,明确了控制BrO_(3)-生成的最佳条件,揭示了BrO_(3)-的生成途径。结果表明,HOC工艺能够高效去除二级出水中的残余有机物,但会生成BrO_(3)-而导致急性毒性增强;p H升高与臭氧投加量的增加均会促进BrO_(3)-的生成,采用氯化铝作为混凝剂时生成的BrO_(3)-量略高于以硫酸铝为混凝剂时的,而有机物可通过控制中间产物次溴酸来抑制BrO_(3)-的生成。基于上述结果,确定HOC最优反应条件如下:p H=7,臭氧投加量为1.0 mg/mg(以TOC衡量)、混凝剂采用氯化铝且投加量为15 mg/L(以Al计)、反应时间为8 min,在该条件下,有机物去除率可保持在30%以上,且BrO_(3)-的生成量<10μg/L,满足《生活饮用水卫生标准》(GB 5749—2006)的要求。BrO_(3)-生成途径包括臭氧直接氧化和羟基自由基(·OH)间接氧化两种,其中臭氧氧化是主要途径,贡献率高达90%。To control the formation of bromate(BrO_(3)-),a disinfection by-product in the secondary effluent from the wastewater treatment plant,the characteristics of BrO_(3)-formation in the hybrid ozonation-coagulation(HOC)process under diverse reaction conditions were investigated,the optimal conditions for controlling BrO_(3)-formation were determined,and the formation pathway of BrO_(3)-was revealed.The HOC process effectively eliminated the residual organic matters in the secondary effluent.However,it generated BrO_(3)-,thereby leading to an increase in acute toxicity.The elevation of pH and the augmentation of ozone dosage facilitated the formation of BrO_(3)-.The quantity of BrO_(3)-generated when aluminum chloride was employed as the coagulant was marginally higher than that when aluminum sulfatewas utilized as the coagulant, and organic matters could impede the formation of BrO_(3)- by regulating theintermediate product hypobromous acid. Based on the aforesaid results, the optimal reaction conditions ofHOC were determined as follows: pH was 7, the dosage of ozone was 1.0 mg/mg(calculated by TOC), thedosage of aluminum chloride was 15 mg/L (calculated by Al), and the reaction time was 8 min. Underthese circumstances, the removal efficiency of organic matter could be maintained above 30%, and theyield of BrO_(3)- was less than 10 μg/L, meeting the limit specified in Standards for Drinking Water Quality(GB 5749-2006). The formation pathway of BrO_(3)- encompassed direct oxidation by ozone and indirectoxidation by hydroxyl radical (·OH), among which ozonation constituted the primary pathway, accountingfor up to 90%.

关 键 词：臭氧混凝耦合工艺 二级出水 溴酸盐 消毒副产物 臭氧氧化 

分 类 号：TU992[建筑科学—市政工程]