Department of Civil and Geological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada.
Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada.
Sci Total Environ. 2017 Dec 1;601-602:543-555. doi: 10.1016/j.scitotenv.2017.05.040. Epub 2017 May 31.
Long term (1999 to 2014) flow and water quality data from a rock drain located at the base of a coal waste rock dump constructed in the Elk Valley, British Columbia was used to characterize the release of three solutes (NO, Cl and SO) from the dump and obtain whole dump estimates of net percolation (NP). The concentrations of dump derived solutes in the rock drain water were diluted by snowmelt waters from the adjacent natural watershed during the spring freshet and reached a maximum concentration during the winter baseflow period. Historical peak baseflow concentrations of conservative ions (NO and Cl) increased until 2006/07 after which they decreased. This decrease was attributed to completion of the flushing of the first pore volume of water stored within the dump. The baseflow SO concentrations increased proportionally with NO and Cl to 2007, but then continued to slowly increase as NO and Cl concentrations decreased. This was attributed to ongoing production of SO due to oxidation of sulfide minerals within the dump. Based on partitioning of the annual volume of water discharged from the rock drain to waste rock effluent (NP) and water entering the rock drain laterally from the natural watershed, the mean NP values were estimated to be 446±50mm/a (area normalized net percolation/year) for the dump and 172±71mm/a for the natural watershed. The difference was attributed to greater rates of recharge in the dump from summer precipitation compared to the natural watershed where rainfall interception and enhanced evapotranspiration will increase water losses. These estimates included water moving through subsurface pathways. However, given the limitations in quantifying these flows the estimated NP rates for both the natural watershed and the waste rock dump are considered to be low, and could be much higher (e.g. ~450mm/a and ~800mm/a).
长期（1999 年至 2014 年）来自不列颠哥伦比亚省麋鹿谷中一座煤矸石堆底部的岩管的流量和水质数据用于描述来自矸石山的三种溶质（NO、Cl 和 SO）的释放，并获得矸石山总渗出量（NP）的整体估算值。岩管水中的矸石山衍生溶质浓度在春季融雪期间被来自相邻自然流域的融雪水稀释，并在冬季基流期达到最大浓度。保守离子（NO 和 Cl）的历史峰值基流浓度一直增加到 2006/07 年，此后才开始下降。这种下降归因于矸石堆中储存的第一体积水的冲洗完成。基流 SO 浓度与 NO 和 Cl 成比例增加到 2007 年，但随后随着 NO 和 Cl 浓度的降低而继续缓慢增加。这归因于矸石堆内硫化物矿物的氧化作用导致 SO 的持续产生。根据从岩管排出的水的年体积分配到矸石废水（NP）和从自然流域侧向进入岩管的水，估计矸石山的平均 NP 值为 446±50mm/a（面积归一化年净渗流），而自然流域的 NP 值为 172±71mm/a。这种差异归因于矸石堆中夏季降水的补给速率大于自然流域，因为自然流域的降雨截留和增强的蒸散会增加水分损失。这些估算值包括通过地下途径移动的水。然而，由于量化这些流量的限制，自然流域和矸石堆的估计 NP 速率被认为很低，并且可能更高（例如，450mm/a 和800mm/a）。
