基于硫酸盐硫同位素的伊洛河流域河水溶解性重金属来源

借助伊洛河河水硫酸盐硫同位素（δ³⁴S_SO4）和溶解性重金属含量水平，研究伊洛河流域不同形式人类活动对河水溶解性重金属的影响.结果表明：伊洛河流域上游干流和支流河水溶解组分受金属矿山开采废水影响较大，洛河河水中溶解性硫酸盐浓度（SO₄^2-）和δ³⁴S_SO4均值分别为（173±108）mg/L和（3.1±2.1）‰（n=8），河水中Co、Fe、Mn、Ni、Zn、Mo、Cd、Pb和U等含量较高，伊河河水中SO₄^2-和δ³⁴S_SO4均值为（169±89）mg/L和（3.7±1.2）‰（n=6），河水中Cr、Co、Fe、Ni、Zn、Mo、Cd、W、Hg、Pb和U等含量较高.伊洛河流域下游河水溶解性重金属受生活污水和工业废水影响较大，洛河河水中SO₄^2-和δ³⁴S_SO4均值分别为（121±30）mg/L和（9.4±0.8）‰（n=4），河水中V、Cr、Ni、As、W和Hg等含量较高，伊河河水中SO₄^2-和δ³⁴S_SO4均值分别为（122±22）mg/L和（10.5±2.4）‰（n=3），河水中V、U、Ni和As等含量较高.伊洛河流域源头河水溶解性重金属含量低，河水溶解组分来自大气降水，河水δ³⁴S_SO4值范围为（6.7‰~8.2‰）.伊洛河流域河水溶解性重金属含量以及δ³⁴S_SO4值具有一致的空间差异性，δ³⁴S_SO4可以很好地说明河水中溶解性重金属以及硫酸盐来源.

Sources of dissolved heavy metals in river water of the Yiluo River basin based on sulfur isotope of sulfate

Sulfur isotopic values of riverine sulfate and dissolved heavy metal (DHM) contents were adopt to illustrate the effect of different human activities on the DHM contents in the Yiluo River (YLR). The results indicated that dissolved components in the upstream of YRB were heavily affected by the sulfide minerals exploration. In the upstream of Luo River, high average SO₄^2- content of (173±108)mg/L (n=8) and low average δ³⁴S_SO4 value of (3.1±2.1)‰ (n=8) were detected in the river water, and heavy metals as Co, Fe, Mn, Ni, Zn, Mo, Cd, Pb and U had high concentrations in this reach. While in the upstream of Yi River, high mean SO₄^2- content of (169±89) mg/L (n=6) and low mean δ³⁴S_SO4 value of (3.7±1.2) ‰ (n=6) were also detected, and heavy metals as Cr, Co, Fe, Ni, Zn, Mo, Cd, W, Hg, Pb and U had relatively high contents. Dissolved contents in the downstream of YRB were primarily affected by sewage and industrial wastewater. Average SO₄^2- content of (121±30) mg/L and δ³⁴S_SO4 value of (9.4±0.8) ‰ (n=4) were monitored in the downstream of Luo River along with the increasing concentrations of V, Cr, Ni, As, W and Hg. Correspondingly, in the downstream of Yi River, average SO₄^2- content of (122±22) mg/L and δ³⁴S_SO4 value of (10.5±2.4) ‰ (n=3) with the increasing concentrations of V, U, Ni, and As were found. Dissolved components in the source water of YLR were mainly derived from atmospheric deposition, and the river water was characterized with low level of DHMs and moderate δ³⁴S values ranging from 6.7‰ to 8.2‰. The contents of DHMs and δ³⁴S_SO4 values in YRB had the same spatial variations, so that the δ³⁴S_SO4 can well interpret the sources of dissolved heavy metals and sulfate in the river water.