College of Earth and Environmental Sciences, MOE Key Laboratory of Western China's Environmental Systems, Key Lab of Environmental Pollution Predict & Control, Lanzhou University, Lanzhou, 730000, PR China.
College of Earth and Environmental Sciences, MOE Key Laboratory of Western China's Environmental Systems, Key Lab of Environmental Pollution Predict & Control, Lanzhou University, Lanzhou, 730000, PR China; Qinghai Jie Shen Environmental Technology Co., LTD, Xining, 810007, Qinghai Province, PR China.
J Environ Manage. 2023 Sep 1;341:118067. doi: 10.1016/j.jenvman.2023.118067. Epub 2023 May 5.
Dissolved organic matter (DOM) is a kind of substance with complex compositions and wide molecular weight distribution, which can strongly combine with various pollutants. Therefore, the binding characteristics of DOM and heavy metal pollutants can be studied specifically according to the binding characteristics of DOM and pollutants. In this study, DOM in surface water bodies was divided into three levels (MW < 1 kDa, 1 kDa < MW < 5 kDa, MW > 5 kDa) according to different molecular weights (MW). The binding properties were investigated by fluorescence spectrum analysis and complex model. Four components (C1-C4) were identified by PARAFAC. Among them, the contribution rate of protein-like components C1, C2 and C4 to the total fluorescence intensity reached more than 78%, and the log K values of low molecular weight components were the highest, which were 3.28, 3.14 and 3.47, respectively, indicating higher binding ability with Cu.With the decrease of molecular weight, the log K value increases, indicating that the complexation is more stable. The humic component C3 in high molecular weight has stronger binding stability with Cu, but the number of binding sites for C3 is 0.36, while that for C2 is 1.51, indicating that its binding sites and binding ability are relatively low. The results showed that the DOM ligand of Cu in surface water showed a certain molecular weight dependence. In addition, different MW DOM lead to different pollution forms. Different properties of DOM ligand combined with Cu were studied in order to control the migration, transformation, bioavailability, morphology and stability of heavy metal pollutants, and to provide theoretical support for the practical application management of surface water pollution control.
溶解有机质（DOM）是一种组成复杂、分子量分布广泛的物质，能与各种污染物强烈结合。因此，可根据 DOM 与污染物的结合特征，具体研究 DOM 与重金属污染物的结合特性。本研究根据不同分子量（MW）将地表水体中的 DOM 分为 3 个水平（MW＜1 kDa、1 kDa＜MW＜5 kDa、MW＞5 kDa）。通过荧光光谱分析和复杂模型研究了其结合特性。通过平行因子分析（PARAFAC）鉴定了 4 个组分（C1-C4）。其中，类蛋白组分 C1、C2 和 C4 对总荧光强度的贡献率均达到 78%以上，小分子组分的 log K 值最高，分别为 3.28、3.14 和 3.47，表明与 Cu 结合能力较高。随着分子量的降低，log K 值增大，表明络合越稳定。高分子量的腐殖质组分 C3 与 Cu 具有较强的结合稳定性，但 C3 的结合位点数为 0.36，而 C2 的结合位点数为 1.51，表明其结合位点和结合能力相对较低。结果表明，地表水中 Cu 的 DOM 配体表现出一定的分子量依赖性。此外，不同 MW DOM 导致不同的污染形态。研究不同性质的 DOM 配体与 Cu 的结合，旨在控制重金属污染物的迁移、转化、生物有效性、形态和稳定性，为地表水环境污染控制的实际应用管理提供理论支持。
