饮用水中异嗅化合物的来源、形成及控制

The nitrogen and phosphorus nutrition, largely induced into water body through modern human activities, usually results in a fast growth of alga and other plankton, and consequently causes a more and more offensive odor in water. Which has threatened the tap water safety that is known as the source of lives in city.Thus, the control of the presence of off-flavor compounds that can compromise the aesthetic qualities of the water supply is becoming a brand-new issue in the international research of drinking water. This proposed project represents the first effort to identify the origin, occurrence and fate of off-flavor compounds in water supply system. To study the off-flavor compounds, flavor profile analysis and advanced instrument analysis will be unitely adopted, and sensitive analytical methods for quantifying the trace compounds will be developed and validated. Then, the method will be applied to track the occurrence of the compounds in water source and water supply system. The removal efficiency of water treatment processes will be evaluated and assessed. For compounds that are present frequently at concentrations above their odor thresholds, their sources and potential for formation within the treatment plant will be determined, and their natural attenuation will be assessed as well. Consequently, a composite control strategy of off-flavor compounds will be discussed and established. The kinetic and thermodynamic data on the origin of off-flavor compounds will provide a basis for understanding the magnitude of the problem and identifying approaches for preventing aesthetic problems in tap water. Thus, the research will provide accurate and precise analytical method for the safety warning of drinking water and supply the reliable data for the criteria definition for monitoring and analyzing of the organic containments. The desired results have significant values for preventing aesthetic problems in tap water and enthancing the credibility of the government.

人类活动使得氮磷等营养物质大量进入水体，引发藻类及其他浮游生物迅速繁殖，异嗅问题凸显。作为"城市生命之源"的自来水，其异嗅的消除成为目前国际上饮用水领域中的一个崭新课题。项目采用感官分析中的嗅味层次分析法与先进的仪器检测技术相结合，在建立精准超痕量异嗅化合物检测体系基础上，通过对源水、自来水处理及输配系统的监测和异嗅化合物形成的研究，意图揭示异嗅化合物的形成机理、确定自来水异嗅的来源，结合异嗅化合物的自然衰减过程研究，由此形成自来水异嗅问题的控制方案和技术。所开展的异嗅化合物生成动力学、热力学研究不仅在机理上有助于增进人们对自来水异嗅问题的认识，项目建立的分析方法也可为饮用水的安全性预警提供快速有效的手段，为饮用水监测、防治及有机污染物系统分析标准方法的制定提供可靠依据，研究结果对于解决自来水异嗅问题、提高政府机构的公信力、保证民众饮用水的安全洁净更是具有重要的现实意义和可期的实用价值。

本报告建立了饮用水中十种异嗅物质、卤代苯甲醚及卤代苯酚的检测方法，并监测其在水厂不同生产环节及管网水的分布，同时研究了十种异嗅化合物在挥发、光催化、生物转化等条件下衰减的规律，提出了自来水异嗅的控制方案及措施。该工作包括：1.饮用水中超痕量致嗅物质的定性定量分析方法和全面检测，即顶空固相微萃取结合气相色谱质谱法同时测定2-异丙基-3-甲氧基吡嗪、(顺，反)-2,6-壬二烯醛、2-异丁基-3甲氧基吡嗪、2-甲基异崁醇、土臭素、β-紫罗酮、2,4,6-三氯苯甲醚、2,3,6-三氯苯甲醚、2,3,4-三氯苯甲醚和2,4,6-三溴苯甲醚，顶空固相微萃取结合气相色谱质谱法同时检测2,4,6-三氯苯甲醚、2,4,6-三溴苯甲醚、邻氯苯酚、邻溴苯酚、2,4-二氯苯酚、2,4-二溴苯酚、2,4,6-三氯苯酚和2,4,6-三溴苯酚，低密度分散液液微萃取结合气相色谱电子捕获检测器法同时测定2,4-二氯苯甲醚、2,6-二氯苯甲醚、2,4,6-三氯苯甲醚、2,3,6-三氯苯甲醚、2,3,4-三氯苯甲醚及2,4,6-三氯苯酚，上述三种方法稳定、可靠；2. 对S市14个大型水库进行了监测，水厂不同生产环节以及管网水进行连续跟踪分析，发现2-甲基异崁醇和土臭素在水体中广泛存在，水厂水样中该两种异嗅物质来源于原水，且所跟踪分析的几个水厂的水处理工艺并不能完全去除这两类物质；3. 通过模拟实验探讨其在挥发、光催化、生物转化等条件下衰减的规律，发现2-异丙基-3-甲氧基吡嗪和2-异丁基-3甲氧基吡嗪较宜使用光氧化氧化技术去除，2-甲基异崁醇和土臭素较宜使用臭氧氧化和活性炭吸附方法除去，β-紫罗酮较宜使用臭氧氧化和光氧化技术去除，2,4,6-三氯苯甲醚、2,3,6-三氯苯甲醚、2,3,4-三氯苯甲醚和2,4,6-三溴苯甲醚臭氧氧化、紫外光氧化和活性炭吸附均合适。4. 对紫外光和次氯酸钠联合降解2-MIB和GSM规律进行了研究，发现联合方式的去除效果远远好于单独的降解方式。对影响外光和次氯酸钠联合降解2-MIB和GSM的因素进行了考察，发现紫外光强度，有效氯浓度，pH值均对2-MIB和GSM的降解效率和降解速率有明显的影响。且随着紫外光强度增强，有效氯浓度增大，pH值增大，2-MIB和GSM的降解效率和降解速率均增大。