School of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454000, China.
School of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454000, China.
Chemosphere. 2023 Jan;310:136747. doi: 10.1016/j.chemosphere.2022.136747. Epub 2022 Oct 7.
Dissolved heavy metals (DHMs) contamination has raised global concern for ecological and human health development. Weathering of sulfide-bearing ore metals can produce acidic, sulfate-rich solutions in the presence of water and oxygen (O), and DHMs are released to deprave the river water quality. Sulfur and oxygen isotope signatures (δS and δO) could identify this pyrite-derived sulfate; however, it is yet not well known whether the δS and δO values could limit the DHMs sources and illustrate anthropogenic impacts on DHMs along the river corridor. We tried to solve this problem through field works in the Luohe River and Yihe River, two tributaries of the Yellow River, China, where metal sulfide mine activities mostly occurred upstream, but agricultural and domestic behaviors concentrated in the lower plain reaches. In the Luohe River upper areas, δS values had negative correlations with concentrations of cadmium (Cd) (p < 0.01), nickel (Ni) (p < 0.05), molybdenum (Mo) (p < 0.01), uranium (U) (p < 0.01), and SO (p < 0.01). However, as the δS values increased downstream in the Luohe River, concentrations of copper (Cu) (p < 0.05), mercury (Hg) (p < 0.05), Ni (p < 0.05), and SO (p < 0.01) simultaneously elevated. The Bayesian Isotope Mixing Model (BIMM) results via δS values demonstrated 64.3%-65.3% of SO from acid mine drainage (AMD) in the Luohe River's upper reaches and 63.5%-67.7% in the Yihe River's upper reaches, and about 33% from sewage and industrial effluents in the Luohe River's lower reaches and 27% in Yihe River's lower reaches. Our results confirmed the different anthropogenic impacts on the DHMs concentrations in Luohe River and Yihe River and provided a robust method for DHMs sources appointment and pollution management in river systems.
溶解态重金属（DHMs）污染引起了全球对生态和人类健康发展的关注。含硫化物矿石金属在水和氧气（O）存在的情况下会风化，产生酸性、富含硫酸盐的溶液，DHMs 被释放出来，使河水水质恶化。硫和氧同位素特征（δS 和 δO）可以识别这种黄铁矿衍生的硫酸盐；然而，目前还不清楚 δS 和 δO 值是否可以限制 DHMs 的来源，并说明人类活动对河流走廊沿线 DHMs 的影响。我们试图通过在中国黄河的两条支流洛河和沂河的野外工作来解决这个问题，金属硫化物矿活动主要发生在上游，但农业和家庭行为集中在下游平原地区。在洛河上游地区，δS 值与镉（Cd）浓度呈负相关（p<0.01）、镍（Ni）（p<0.05）、钼（Mo）（p<0.01）、铀（U）（p<0.01）和 SO（p<0.01）。然而，随着洛河下游 δS 值的增加，铜（Cu）浓度（p<0.05）、汞（Hg）（p<0.05）、Ni（p<0.05）和 SO（p<0.01）同时升高。通过 δS 值的贝叶斯同位素混合模型（BIMM）结果表明，洛河上游的 SO 有 64.3%-65.3%来自酸性矿山排水（AMD），沂河上游有 63.5%-67.7%来自污水和工业废水，洛河下游有 33%左右，沂河下游有 27%来自污水和工业废水。我们的结果证实了洛河和沂河 DHMs 浓度受不同人为因素的影响，并为河流系统中 DHMs 来源的指定和污染管理提供了一种可靠的方法。
