石灰石沟-堆肥湿地系统处理酸性矿山废水的研究

为探讨石灰石沟-潜流堆肥湿地系统处理酸性矿山废水(AMD)的效果及影响因素,进行了6个月模拟试验,测定出水水质和植物生长等相关的影响因素.结果表明,石灰石沟可有效提高AMD的pH值,降低其酸度与重金属含量,但随着石灰石沟中氢氧化物的积累,后期处理性能下降;堆肥湿地可显著降低AMD的酸度与重金属,出水酸度随时间持续降低,出水的Cd、Pb在检测限以下,Zn、Cu平均浓度分别为1.8mg/L, 2.6μg/L,均达到农业灌溉水标准,而无前置堆肥的普通湿地后期Cd、Zn、Cu偏高;东南景天在湿地系统也能正常富积Cd/Zn;狭叶香蒲使堆肥湿地的产碱过程受到抑制,出水酸度升高,但其对堆肥湿地的重金属去除没有产生显著影响.

The treatment of acidic mine drainage using limestone ditch and compost constructed wetland system

In order to evaluate the performance and affecting factors of a limestone ditch-compost wetlands system to treat acidic mine drainage (AMD), a pilot test for six months was conducted with the measurements of effluents quality and plant growth-related parameters. Results show that limestone ditch (LSD) can effectively increase pH, decrease acidity and heavy metals of AMD, but the efficiency declined with the accumulation of metal hydroxides in LSD. The acidity and heavy metals decreased significantly after passing through compost wetlands, the acidity of the effluents decreased continuously and concentrations of Cd, Pb were below the levels of detection, the mean concentrations of Zn, Cu were 1.8mg/L, 2.6μg/L, respectively, which conform to the standards for irrigation water quality. However, much higher concentrations of Cd, Zn were found in the effluents of wetlands without the addition of compost. Sedum alfredii Hance planted in wetlands grew and extracted normally Cd/Zn. Alkalinity production in compost wetlands were inhibited in the presence of Typha angustifolia, and the acidity of the effluents were increased, but heavy metals removals were not significantly affected by planting Typha angustifolia.