School of Environmental Studies, China University of Geosciences, 388 Lumo Rd, Wuhan 430074, China.
Yunan Chihong Zinc and Germanium Co., Ltd. Huize Branch, Huize 654212, China.
Int J Environ Res Public Health. 2019 Feb 2;16(3):443. doi: 10.3390/ijerph16030443.
Slag heaps are formed by mining waste materials, and the improper treatment of leachate from such heaps can threaten nearby aquifers. The Zhehai slag heap in Yunnan Province, China, contains 2.7 million tons of zinc and cadmium slag, and is considered a heavy metal source threatening the local groundwater safety, however, the severity of contamination remains unknown. In this study, numerical modeling was used to predict the groundwater flow and contaminant transport in this area based on field data. The results show that the atmospheric precipitation infiltration recharge at the top of the heap is 81.8 m³/d, accounting for 93.76% of total infiltration. The south and east sides of the area are the main outflow channels for contaminants, accounting for 93.25% of the total discharge around the heap. To reduce aquifer contamination, an in situ system involving a "controlling the source, 'breaking' the path, and intercepting the flow" (CSBPIF) strategy is established. The results indicate that the system performs well because it not only decreases the flow velocity but also reduces the concentrations of contaminants adsorbed by clay media. Moreover, the equivalent bottom liner thicknesses of the clay layers were calculated to improve the applicability of the CSBPIF system. Compared with ex situ disposal, this scheme provides an economic and effective solution and can be used to prevent and control groundwater pollution in China.
渣堆是由采矿废物形成的，如果对这些渣堆的渗滤液处理不当，可能会威胁到附近的含水层。中国云南省的蔗海渣堆含有 270 万吨锌和镉渣，被认为是威胁当地地下水安全的重金属污染源，但污染的严重程度尚不清楚。在本研究中，根据现场数据，利用数值模拟方法预测了该地区的地下水流动和污染物运移。结果表明，堆顶大气降水入渗补给量为 81.8m³/d，占总入渗量的 93.76%。该区域的南侧和东侧是污染物的主要流出通道，占堆周总排放量的 93.25%。为了减少含水层的污染，建立了一个包括“源头控制、路径阻断、水流拦截”（CSBPIF）策略的原位系统。结果表明，该系统性能良好，因为它不仅降低了流速，而且降低了被粘土介质吸附的污染物浓度。此外，还计算了粘土层的等效底部衬垫厚度，以提高 CSBPIF 系统的适用性。与异位处理相比，该方案提供了一种经济有效的解决方案，可用于预防和控制中国的地下水污染。
