湖泊水体溶解性有机物光化学活性构效关系研究  

Research on structure-activity relationship of photochemical activity of dissolved organic matter in lake waters

作　　者：王兴 员乐 陈勇[1] WANG Xing;YUN Le;CHEN Yong(School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学环境科学与工程学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2024年第10期116-122,共7页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金面上项目(21876056)。

摘　　要：以武汉市5个流域城镇化程度不同的湖泊为研究对象,探究城镇化过程对湖泊水体水质及溶解性有机物(DOM)紫外-可见吸收光谱特征的影响;通过东湖水体DOM激发三线态(^(3)DOM^(*))、单线态氧(^(1)O_(2))和羟基自由基(^(·)OH)三种光致活性物质生成与光谱特征指数之间的相关性构建湖泊水体光致活性物质量子产率的预测模型,并应用于其他湖泊水体DOM光化学活性的预测.结果表明:湖泊水体DOM平均分子质量和有色溶解性有机物(CDOM)相对贡献均随流域城镇化程度的提高而增大;在模拟太阳光照射下,东湖水体^(3)DOM^(*),^(1)O_(2)和^(·)OH量子产率与E_(2)/E_(3)(254 nm与365 nm处吸收系数之比)和S_(1)(290~400 nm光谱斜率)呈显著正相关,与a_(355)(355 nm处吸收系数)呈显著负相关;基于上述相关性建立的预测模型对其余四个湖泊水体^(3)DOM^(*)和^(1)O_(2)的量子产率有良好的预测效果.Five lakes with different degrees of basin urbanization in Wuhan City were selected as the research objects to explore the influence of urbanization process on water quality and UV-visible absorption spectral characteristics of dissolved organic matter(DOM) in lake waters.Based on the correlation between the formation of three reactive species,DOM excited triaxial states(^(3)DOM^(*)),singlet oxygen(^(1)O_(2)) and hydroxyl radical(^(·)OH),and the spectral characteristic index of East Lake water,the prediction model of the quantum yield of reactive species in lake water was established and applied to the prediction of DOM photochemical activity in other lake waters.Results show that the average molecular weight of DOM and the relative contribution of colored dissolved organic matter(CDOM) increase with increasing basin urbanization degree.Under simulated sunlight irradiation,the quantum yields of ^(3)DOM^(*),^(1)O_(2) and ^(·)OH are significantly positively correlated with E_(2)/E_(3)(ratio of absorption coefficients at 254 nm to365 nm) and S,(spectral slope from 290 nm to 400 nm),and significantly negatively correlated with a_(355)(absorption coefficient at355 nm).The prediction model established based on the above correlation has good prediction for the quantum yield of ^(3)DOM^(*) and ^(1)O_(2) in the remaining four lake waters.

关 键 词：流域城镇化 湖泊水体 溶解性有机物 光化学活性 构效关系 

分 类 号：X131.2[环境科学与工程—环境科学]