摘要
春末夏初是长江流域水源水库水质异味问题的高发期,但关于该区域水库异味物质发生特征及影响因子尚不明晰。2024年5月调查了长江流域上、中、下游不同省份9座水源水库坝前区域水体2-甲基异莰醇(2-MIB)等异味物质浓度状况及其环境条件,探讨了春季影响该区域水源水库异味物质浓度的生态环境因子。结果表明,2-MIB是春季长江流域水源水库中最常见的超标异味物质,9座水库坝前水柱2-MIB浓度均值为35.5 ng/L,超过《生活饮用水卫生标准》中该物质控制浓度阈值(10.0 ng/L)的样品数占比为59.4%;相比而言,土臭素均值仅为2.9 ng/L,超过《生活饮用水卫生标准》中该物质控制浓度阈值(10.0 ng/L)的样品数占比仅为12.5%;异味物质β-环柠檬醛的均值为18.2 ng/L,β-环紫罗兰酮的均值为7.2 ng/L,引起饮用水异味问题的风险小。2-MIB的源解析表明,假鱼腥藻(Pseudanabaena sp.)可能是该区域水源水库中2-MIB的主要来源,其细胞密度与2-MIB浓度呈显著正相关;但也存在部分水库检测到2-MIB但未检出假鱼腥藻的现象,反映出2-MIB来源的复杂性。富营养化会导致2-MIB异味问题风险显著升高,2-MIB浓度与水体营养状态指数呈正相关。调查前一周内的累计降雨量与2-MIB浓度呈负相关,推测短期强降雨等气象条件变化会通过显著改变水柱混合作用、引起藻类群落演替等方式导致水库2-MIB浓度突变。研究表明,虽然长江流域的水源水库大都处于中营养水平,但普遍面临2-MIB超标的水质异味风险。加强外源营养盐入库负荷控制,优化库体食物链结构,进一步降低水库营养状态,有助于提升水库型水源地的供水质量。
There is a very high risk of odorous compounds contaminating drinking water sources in the Changjiang River catchment in spring.However,the key drivers for the occurrence of odorous compounds are still unclear.In May 2024,nine drinking water source reservoirs across the upper,middle and lower reaches of the Changjiang River were investigated.Four odorous compounds,2-methylisoborneol(2-MIB),geosmin(GSM),β-cyclocitral(CYC)andβ-ionone(ION)and their associated environmental factors were surveyed.The results showed that 2-MIB was the most common odorous compound in the research region,with an average concentration of 35.5 ng/L across the 32 samples from 9 reservoirs(59.4%exceeding the drinking water standard of 10.0 ng/L).GSM posed a lower risk,with an average concentration of 2.9 ng/L and only 12.5%exceeding the threshold value of 10 ng/L.CYC(averaged at 18.2 ng/L)and ION(averaged at 7.2 ng/L)exhibited minimal odorous concerns.Pseudanabaena sp.was identified as a likely major producer of 2-MIB,with its cell density showing a significant positive correlation with the concentration of 2-MIB.However,the presence of 2-MIB in two reservoirs without detectable Pseudanabaena,indicated more complex 2-MIB sources in some reservoirs.2-MIB levels positively correlated with the trophic state index,demonstrating that eutrophication directly promotes 2-MIB production.The 7-day accumulated rainfall amount before sampling was negatively correlated with the 2-MIB concentration,suggesting that short-term heavy rainfall processes will strongly change the odor compounds risk in reservoirs.Despite most drinking water source reservoirs in this region were under mesotrophic conditions,while it showed widespread 2-MIB exceedances.It is vital to reduce external nutrient loads and optimize aquatic food webs to prevent odorous issues and ensure drinking safety.
作者
韦彦章
朱广伟
池怡
黄昌春
肖曼
Wei Yanzhang;Zhu Guangwei;Chi Yi;Huang Changchun;Xiao Man(School of Geographical Sciences,Nanjing Normal University,Nanjing 210023,P.R.China;State Key Laboratory of Lake and Watershed Science for Water Security,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 211135,P.R.China;University of Chinese Academy of Sciences,Nanjing,Nanjing 211135,P.R.China;Ecological and Environmental Monitoring Center of Hangzhou,Hangzhou 310000,P.R.China)
出处
《湖泊科学》
北大核心
2026年第1期78-90,共13页
Journal of Lake Sciences
基金
国家自然科学基金项目(42271080,U2340209)
中国科学院南京地理与湖泊研究所自主部署科研项目(NIGLAS2022GS03)联合资助。
关键词
长江流域
水源水库
中营养
2-甲基异莰醇
假鱼腥藻
Changjiang River catchment
drinking water source reservoir
mesotrophic
2-methylisoborneol
Pseudanabaena
