Leonard Laura T, Vanzin Gary F, Garayburu-Caruso Vanessa A, Lau Stephanie S, Beutler Curtis A, Newman Alexander W, Mitch William A, Stegen James C, Williams Kenneth H, Sharp Jonathan O
Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401, United States.
Pacific Northwest National Laboratory, Richland, WA 99354, United States.
Water Res X. 2022 Apr 25;15:100144. doi: 10.1016/j.wroa.2022.100144. eCollection 2022 May 1.
Changes in climate, season, and vegetation can alter organic export from watersheds. While an accepted tradeoff to protect public health, disinfection processes during drinking water treatment can adversely react with organic compounds to form disinfection byproducts (DBPs). By extension, DBP monitoring can yield insights into hydrobiogeochemical dynamics within watersheds and their implications for water resource management. In this study, we analyzed temporal trends from a water treatment facility that sources water from Coal Creek in Crested Butte, Colorado. These trends revealed a long-term increase in haloacetic acid and trihalomethane formation over the period of 2005-2020. Disproportionate export of dissolved organic carbon and formation of DBPs that exceeded maximum contaminant levels were consistently recorded in association with late spring freshet. Synoptic sampling of the creek in 2020 and 2021 identified a biogeochemical hotspot for organic carbon export in the upper domain of the watershed that contained a prominent fulvic acid-like fluorescent signature. DBP formation potential analyses from this domain yielded similar ratios of regulated DBP classes to those formed at the drinking water facility. Spectrometric qualitative analyses of pre and post-reacted waters with hypochlorite indicated lignin-like and condensed hydrocarbon-like molecules were the major reactive chemical classes during chlorine-based disinfection. This study demonstrates how drinking water quality archives combined with synoptic sampling and targeted analyses can be used to identify and understand export control points for dissolved organic matter. This approach could be applied to identify and characterize analogous watersheds where seasonal or climate-associated organic matter export challenge water treatment disinfection and by extension inform watershed management and drinking water treatment.
气候、季节和植被的变化会改变流域的有机物质输出。虽然为保护公众健康进行消毒处理是一种公认的权衡，但饮用水处理过程中的消毒过程可能会与有机化合物发生不良反应，形成消毒副产物（DBPs）。由此推断，DBP监测可以深入了解流域内的水生物地球化学动态及其对水资源管理的影响。在本研究中，我们分析了科罗拉多州克雷斯特德比特市一处从煤溪取水的水处理设施的时间趋势。这些趋势显示，在2005年至2020年期间，卤乙酸和三卤甲烷的生成呈长期增加趋势。与晚春洪水相关，溶解有机碳的不成比例输出以及超过最大污染物水平的DBP生成一直有记录。2020年和2021年对该溪流的综合采样确定了流域上游区域有机碳输出的一个生物地球化学热点，该区域具有明显的类富里酸荧光特征。该区域的DBP生成潜力分析得出的受监管DBP类别比例与饮用水处理设施中形成的比例相似。用次氯酸盐对反应前后的水进行光谱定性分析表明，在基于氯的消毒过程中，类木质素和类缩合烃分子是主要的反应化学类别。本研究展示了如何将饮用水质量档案与综合采样和针对性分析相结合，以识别和理解溶解有机物的输出控制点。这种方法可用于识别和表征类似的流域，在这些流域中，季节性或与气候相关的有机物质输出对饮用水处理消毒构成挑战，进而为流域管理和饮用水处理提供信息。
