北江流域多金属矿山重金属随径流泥沙迁移特征研究

采用野外原位小区模拟径流冲刷试验对北江流域上游的广东大宝山矿区不同年限堆积土重金属随径流泥沙迁移特征进行了研究，结果表明：a）新弃土、老弃土侵蚀泥沙中cd、Pb、zn、cu重金属含量均高于自然土侵蚀泥沙，但新弃土、老弃土侵蚀泥沙重金属含量相差不大；b）新弃土、老弃土、自然土侵蚀泥沙Cd的平均流失率为32．55、12．18、0．09mg/（min·m^2），Pb的平均流失率为1648．98、432．10、8．07mg／（min．m^2），Zn的平均流失率为1854．35、460．14、4．92mg／（min．m^2），Cu的平均流失率为1742．63、429．47、8．69mg／（min·m^2），新弃土、老弃土重金属平均流失率要远远高于自然土；c）新弃土、老弃土侵蚀泥沙cd、Pb、zn、cu流失率随时间均呈下降趋势。在冲刷初期，新弃土、老弃土侵蚀泥沙重金属平均流失率较大，有明显的“初期冲刷”效应；d）在冲刷的20分钟里，新弃土、老弃土、自然土侵蚀泥沙中的累积流失量分别为：Cd为651．00、243．62、1．79mg，Pb为32．98、8．64、0．16g，Zn为37．09、9．20、0．10g，Cu为34．85、8．59、0．17g，在相同时段内，新弃土、老弃土重金属流失总量要远远高于自然土。

Study on heavy metal migration characteristics with runoff sediment of polymetallic mine in Beijiang River basin

The erosion characteristics of heavy metal, existing in accumulated soils spoiled in different years in Dabaoshan Mine in upstream of Beijiang River, had been studied, and the results were as follows： 1） The avemge Cd content of eroded sediment of new spoiled soil, old spoiled soil and nature soil were 38.41, 37.62, 3.36mg/kg separately; the avemge soil Pb content were 1647.75, 1607.08, 304. 57mg/kg separately; the avemge soil Zn content were 1818.16, 1611.58, 177. 66mg/kg separately; the avemge soil Cu content were 1683.91, 1465. 13g, 322. 89mg/kg separately. The heavy meal content of new spoiled soil and old spoil soil, differed little from each other, were higher than that of nature soil. 2） The avemge Cd loss rate in eroded sediment of new spoiled soil, old spoiled soil and nature soil 32. 55, 12. 18, 0. 09 mg/（ min. m^2） ; avemge loss rate of Pb were 1648.98, 432. 10, 8.07mg/（ min. m^2） ; avemge loss rate of Zn were 1854. 35, 460. 14, 4. 92 mg/（ min. m^2）, and avemge loss rate of Cu were 1742.63, 429. 47, 8.69 mg/ （min. mZ）. The number of natural soil were lower much than the other two. 3）The eroded sediment loss rate of Cd, Pb, Zn and Cu in new spoiled soil and old spoiled soil all showed an ascendant trend. At the beginning of scouring, the avemge loss rate of eroded sedi- ment of new spoiled soil and old spoiled soil were significant, showing an ＂incipient scour＂ effect. 4） In the first 20 minutes, the accu- mulated erosion amount of heavy metal in new spoiled soil, old spoil soil and nature soil were： Cd 651.00, 243.62, 1.79mg; Pb 32.98, 8.64, 0. 16g; Zu 37.09, 9.20, 0.10g; Cu 34. 85, 8.59, 0.17g. During the same period, the total erosion amount of new spoil soil and old spoil soil exceed nature soil a lot.