卤代苯醌类新型消毒副产物生成机制与控制技术研究

Halobenzoquinones, as a group of emerging disinfection by-products (DBPs) in drinking water，have recently raised great concerns because of their high carcinogenic potency and detection rate in waterworks effluent. However, the characteristics of the halobenzoquinones precursors and its formation mechanism are unclear, and the migration and transformation of halobenzoquinones precursors in water treatment technology has not been well studied. The occurrence of the halobenzoquinones in waterworks has not been investigated until now referring to the raw water quality in China. In order to study the formation and control of halobenzoquinones during the drinking water treatment, we would investigate the occurrence of halobenzoquinones (precursors) in drinking water plants firstly, and evaluate the characteristics of precursors according to function group and molecular structure study. On the basis of the precursor confirmation, model compound would be selected for the investigation of halobenzoquinones formation processes and influence factors. Then it would be well studied that the precursor migration and transformation in different water treatment processes such as enhanced conventional treatment, ozonation, and activated carbon treatment. The control efficiency of halobenzoquinones would be evaluated. Based on the studies, we would construct the theory system of halobenzoquinones formation and control, which would be important for water supply industry and improving drinking water standard.

卤代苯醌（halobenzoquinones，HBQs）作为饮用水中新型消毒副产物，因具有强致癌风险和高检出率逐渐受到关注，但目前对导致HBQs生成的前驱物特征、生成机制及水处理工艺中前驱物行为缺乏认识，HBQs在我国水质条件下的存在水平尚无研究，导致水源管理和水厂处理风险难于控制。本项目对我国典型饮用水源、水厂及管网HBQs类消毒副产物存在状况进行调研，结合水源有机物官能团及分子结构等表征，识别HBQs前驱物特征，并利用模式物质进行验证；在此基础上，对前驱物在不同消毒条件下中间产物变化、HBQs生成过程进行分子水平解析，阐明生成机理及路径；针对预处理强化常规工艺及臭氧、活性炭深度处理工艺，考察HBQs前驱物在不同处理技术和条件下的行为机制，明确控制HBQs生成的技术和工艺条件。本项目研究结果将完善HBQs消毒副产物生成与控制理论，保障饮用水安全，也为将来生活饮用水标准的完善提供数据支持。

卤代苯醌（HBQs）是饮用水中一种新型消毒副产物，其浓度虽较低，但毒性却比三卤甲烷、卤乙酸等常规消毒副产物强，可能导致膀胱癌，存在潜在遗传毒性。目前针对HBQs的研究主要集中在检测方法建立及国外部分水厂调查。本项目主要以2,6-DCBQ和二溴苯醌（2,6-DBBQ）为研究对象，建立检测方法并调查其在管网的浓度水平，探讨形成过程和影响因素，考察不同处理工艺对其去除效果。主要得到以下结论：.建立了HBQs浓缩富集方法及前体物实验预处理方法，采用固相萃取（SPE）-高效液质联用（HPLC-MS）法，在典型城市饮用水管网出水中，检测出2,6-DCBQ浓度为0-22.17ng/L，2,6DBBQ未检出。研究中采用多种酚类化合物进行氯化消毒研究，发现均有HBQs生成，在生成HBQs的过程中，苯酚先被次氯/溴酸取代成为2,4,6-三氯/溴苯酚，继而与次氯/溴酸发生氧化反应，最后生成2,6-DCBQ/2,6DBBQ。 pH值、投氯量、溴离子浓度均会影响2,6-DCBQ的生成，生成量在4-8小时达到最大值之后减小，由于次氯酸钠和生成的2,6-DCBQ反应，生成小分子物质。碱性条件不利于2,6-DCBQ 的生成，其在碱性条件下易分解，pH的升高还影响次氯酸的分布系数，因此在pH为6时生成量最高。投氯量小于0.5mmol/L时，2,6-DCBQ 的生成量随着投加量的增加而增加，投氯量超过于0.5mmol/L时，生成的2,6-DCBQ被取代为三羟基-2,6-二氯-1,4-苯醌，因此生成量减少。.颗粒活性炭（GAC）对HBQs有很好的去除效果，当GAC投加量从0.2g/L增至0.8g/L时，2,6-DCBQ的去除率从30.0%升至80.1%，2,6-DBBQ的去除率从36.2%升至70.6%。柱形活性炭对HBQs的去除效果低于颗粒活性炭，当投加量从0.2g/L增至0.8g/L时，2,6-DCBQ和2,6-DBBQ的去除率为40%-50%。混凝沉淀对二氯苯醌生成势有较好的去除作用。臭氧氧化处理能使DCBQFP降低10.0-30.0%，臭氧对2,6-DCBQ去除率为35.1%。