Abstract Utilization of multiple stable isotopes including metal isotopes have been useful to trace sources and pathways of contamination. Contaminated seepages flow out from tailings dumps at the Daema gold-silver mine and the Okdong copper mine in South Korea. Ion concentrations, δ34SSO4, δ18OSO4, and Pb isotopes, as well as leaching tests were used to evaluate the sources and pathways of seepages from tailings dumps at the Daema and Okdong mines. The δ34SSO4 and δ18OSO4 values of the seepage were similar to that of the groundwater at the tailings layer and differed from that of the groundwater at the coal shale layer of the tailings dump at the Daema mine. The Pb isotopic ratios of groundwater at the tailings layer also approached those of the tailings, although the Pb concentration in the seepage that was too low (0.559 μg L−1) did not indicate isotopic signatures of tailings. This suggests that the source of contaminants in the seepage is the tailings of the Daema mine rather than waste rocks (coal shale) of an adjacent mine in the tailings dump. In the Okdong mine, the contamination of seepage may be a result of a 67–71% contribution of groundwater from the northern side of the dump through buried waste rock (OD-T2) and a 19–23% contribution of groundwater from the eastern valley (OD-T3), as calculated by the isotopic mixing of δ34SSO4 and δ18OSO4. Adit water is not considered to be the major source of the seepage because of the large difference in Mn concentrations (22.0 mg L−1 and 0.10 mg L−1 in adit water and seepage, respectively) and the undersaturation with respect to Mn phases before and after mixing with tailings water. To reduce the contamination load of seepage in a tailings dump, we should prevent water inflow not only from the surface but also from the side of the tailings dump. Both studied areas suggest that a dual isotopic approach using δ34SSO4 and δ18OSO4 is especially useful in identifying the contamination sources and pathways. Additionally, a leaching test for waste evaluation proved helpful in qualitatively simulating the composition of leachate from the tailings at the Daema mine and adit water from ore rocks at the Okdong mine. Dissolved Pb isotopic ratios were effective in determining the solid sources of dissolved Pb, if the Pb concentration is greater than 0.6–1.8 μg L−1 in the cases of the studied mines. Pb isotopic ratios at five sites including Nakdong mine and two other sites suggest that dissolved Pb with too low concentration may have isotopic signature of atmospheric input. Pb concentrations above threshold values may be required to reflect contamination sources other than atmospheric contribution.

中文翻译：

---

使用韩国大马和玉洞矿的硫酸盐和铅同位素确定矿山渗漏的来源和途径

摘要 利用包括金属同位素在内的多种稳定同位素可用于追踪污染源和途径。韩国大马金银矿和玉洞铜矿的尾矿场流出受污染的渗漏液。使用离子浓度、δ34SSO4、δ18OSO4 和 Pb 同位素以及浸出测试来评估 Daema 和 Okdong 矿山尾矿倾倒场渗漏的来源和途径。渗流的δ34SSO4和δ18OSO4值与尾矿层地下水相似，与大马矿尾矿倾倒煤页岩层地下水不同。尾矿层地下水的 Pb 同位素比也接近尾矿层的 Pb 同位素比，尽管渗流中的 Pb 浓度太低（0. 559 μg L-1) 没有表明尾矿的同位素特征。这表明渗流中的污染物来源是大马矿的尾矿，而不是尾矿堆中相邻矿井的废石（煤页岩）。在 Okdong 矿，渗漏污染可能是来自垃圾场北侧的 67-71% 的地下水通过掩埋的废石 (OD-T2) 和 19-23% 的来自东部的地下水贡献的结果。谷 (OD-T3)，由 δ34SSO4 和 δ18OSO4 的同位素混合计算得出。由于 Mn 浓度的巨大差异（分别为 22.0 mg L-1 和 0.10 mg L-1，分别为 22.0 mg L-1 和 0.10 mg L-1）和渗流之前的 Mn 相不饱和与尾矿水混合后。为降低尾矿场渗流污染负荷，不仅要防止水从地表流入，还要防止从尾矿场侧面流入。两个研究区域都表明，使用 δ34SSO4 和 δ18OSO4 的双同位素方法在确定污染源和途径方面特别有用。此外，废物评估的浸出试验证明有助于定性模拟大马矿尾矿的渗滤液和玉东矿的矿石岩石的渗滤液组成。如果在所研究矿山的情况下 Pb 浓度大于 0.6-1.8 μg L-1，则溶解 Pb 同位素比率可有效确定溶解 Pb 的固体来源。包括洛东矿和其他两个地点在内的五个地点的铅同位素比率表明，浓度过低的溶解铅可能具有大气输入的同位素特征。可能需要高于阈值的铅浓度来反映除大气贡献之外的污染源。