摘要
为了探讨模拟降雨条件下德兴铜矿尾砂重金属的淋出规律及释放特征,采用4种不同酸度的淋溶液模拟降雨进行为期60 d的动态淋溶试验。结果表明:尾砂淋出液pH值呈现先降低后小幅波动的变化趋势,且4种酸度淋溶液间的差异较小;电导率呈现先降低后趋于稳定的变化趋势,且pH=4处理组的淋出液电导率显著高于其他3种处理;各重金属的累积淋出量均呈现逐渐增加的变化趋势,且淋溶液酸度越低重金属累积淋出量越高,此外Cd和Hg的累积淋出率较高,长期酸雨可能导致潜在的环境污染。采用动力学方程拟合发现,双常数速率方程可以更好地描述Cu和Zn的释放过程,修正的Elovich方程则更适合描述Pb、Cd、As和Hg的释放过程,这表明模拟酸雨淋溶作用下尾砂重金属的释放是一个由多因素综合控制的过程。
To investigate the leaching rule and release characteristics of heavy metals from tailings under simulated rainfall in Dexing Copper Mine, 4 kinds of leaching solutions with different acidity were used to simulate rainfall for a dynamic leaching test lasting 60 d.The results showed that the pH values of leaching solutions of tailings decreased at first and then fluctuated slowly, and slight difference was found among 4 kinds of leaching solutions.The electrical conductivity tended to decrease at first and then to be stable, and the electric conductivity of the leaching solution treated under the condition of pH=4 was significantly higher than that of other three treatments.The cumulative leaching amount of each heavy metal showed a gradually increasing trend, and the lower the acidity of the leaching solution was, the higher cumulative leaching amount of heavy metals becomes.Meanwhile, the cumulative leaching rate of Cd and Hg was higher so that long-term acid rain might lead to potential environmental pollution.It was founded by the fitting of dynamic equation that the release processes of Cu and Zn could be better described by using a double constant rate equation, and the modified Elovich equation was more suitable for describing the release process of Pb, Cd, As and Hg.These indicated that the release of heavy metals from tailings under the leaching function of simulated acid rain was a process controlled by multiple factors.
作者
濮阳雪华
邓汝英
王春春
黄娟
宋桂龙
PU-YANG Xue-hua;DENG Ru-ying;WANG Chun-chun;HUANG Juan;SONG Gui-long(Shenzhen Techand Ecology & Environment Co., Ltd, Shenzhen 518040, China;Institute of Turfgrass Science, Beijing Forestry University, Beijing 100083, China)
出处
《环境工程》
CAS
CSCD
北大核心
2019年第5期61-65,共5页
Environmental Engineering
基金
国家重点研发计划"西北干旱荒漠区煤炭基地生态安全保障技术"(2017YFC0504400)
"矿区生态修复与生态安全保障技术集成示范研究"(2017YFC0504406)
关键词
铜矿
尾砂
重金属
模拟降雨
淋溶特征
copper mine
tailings
heavy metals
simulated rainfall
leaching characteristics
