Lee Jin-Yong, Choi Jung-Chan, Lee Kang-Kun
GeoGreen21 Co., Ltd., Seoul National University, Suite 520, Main Building, Research Park, Pongchon7-dong, Seoul, 151-818, South Korea.
Environ Geochem Health. 2005 Sep;27(3):237-57. doi: 10.1007/s10653-004-3480-7.
This study evaluated variations in heavy metal contamination of stream waters and groundwaters affected by an abandoned lead-zinc mine, where a rockfill dam for water storage will be built 11 km downstream. For these purposes, a total of 10 rounds of stream and groundwater samplings and subsequent chemical analyses were performed during 2002-2003. Results of an exploratory investigation of stream waters in 2000 indicated substantial contamination with heavy metals including zinc (Zn), iron (Fe) and arsenic (As) for at least 6 km downstream from the mine. Stream waters near the mine showed metal contamination as high as arsenic (As) 8,923 microg L(-1), copper (Cu) 616 microg L(-1), cadmium (Cd) 223 microg L(-1) and lead (Pb) 10,590 microg L(-1), which greatly exceeded the Korean stream water guidelines. Remediation focused on the mine tailing piles largely improved the stream water qualities. However, there have still been quality problems for the waters containing relatively high concentrations of As (6-174 microg L(-1)), Cd (1-46 microg L(-1)) and Pb (2-26 microg L(-1)). Rainfall infiltration into the mine tailing piles resulted in an increase of heavy metals in the stream waters due to direct discharge of waste effluent, while dilution of the contaminated stream waters improved the water quality due to mixing with metal free rain waters. Levels of As, Cu and chromium (Cr) largely decreased after heavy rain but that of Pb was rather elevated. The stream waters were characterized by high concentrations of calcium (Ca) and sulfate (SO(4)), which were derived from dissolution and leaching of carbonate and sulfide minerals. It was observed that the proportions of Ca and SO(4) increased while those of bicarbonate (HCO(3)) and sodium and potassium (Na+K) decreased after a light rainfall event. Most interestingly, the reverse was generally detected for the groundwaters. The zinc, being the metal mined, was the most dominant heavy metal in the groundwaters (1758-10,550 microg L(-1)) near the mine, which far exceeded the Korean standard of 1000 microg L(-1) for drinking water. The decreases in the heavy metals contents in the groundwaters associated with reduced rainfall were quite different from the increases observed for the stream waters, which is not clearly understood at this time and warrants further investigation.
本研究评估了受一座废弃铅锌矿影响的溪流水和地下水中重金属污染的变化情况，该矿下游11公里处将修建一座用于蓄水的堆石坝。为此，在2002年至2003年期间共进行了10轮溪流水和地下水采样及后续化学分析。2000年对溪流水的初步调查结果表明，在该矿下游至少6公里范围内，锌（Zn）、铁（Fe）和砷（As）等重金属存在大量污染。靠近该矿的溪流水显示出高达砷（As）8923微克/升、铜（Cu）616微克/升、镉（Cd）223微克/升和铅（Pb）10590微克/升的金属污染，大大超过了韩国溪流水质标准。针对矿尾矿堆的修复措施在很大程度上改善了溪流水质。然而，对于含有相对高浓度砷（6 - 174微克/升）、镉（1 - 46微克/升）和铅（2 - 26微克/升）的水体，仍然存在水质问题。降雨渗入矿尾矿堆导致溪流水体中的重金属增加，这是由于废水的直接排放，而受污染溪流水体的稀释则因与无金属雨水混合而改善了水质。大雨过后，砷、铜和铬（Cr）的含量大幅下降，但铅的含量却有所升高。溪流水体的特征是钙（Ca）和硫酸根（SO₄）浓度较高，这是由碳酸盐和硫化物矿物的溶解和淋溶所致。观察到在一场小雨事件后，钙和硫酸根的比例增加，而碳酸氢根（HCO₃）以及钠和钾（Na + K）的比例下降。最有趣的是，地下水中的情况通常相反。锌作为被开采的金属，是该矿附近地下水中最主要的重金属（1758 - 10550微克/升），远远超过了韩国饮用水标准的1000微克/升。地下水中重金属含量随降雨量减少而降低，这与溪流水体中观察到的增加情况截然不同，目前尚不清楚原因，值得进一步研究。
