Hulshof Andrea H M, Blowes David W, Gould W Douglas
Department of Earth Sciences, University of Waterloo, Waterloo, Ont., Canada N2L 3G1.
Water Res. 2006 May;40(9):1816-26. doi: 10.1016/j.watres.2006.03.003. Epub 2006 Apr 19.
Reactive treatment layers, containing labile organic carbon, were evaluated to determine their ability to promote sulfate reduction and metal sulfide precipitation within a tailings impoundment, thereby treating tailings effluent prior to discharge. Organic carbon materials, including woodchips and pulp waste, were mixed with the upper meter of tailings in two separate test cells, a third control cell contained only tailings. In the woodchip cell sulfate reduction rates were 500 mg L-1a-1, (5.2 mmol L-1a-1) this was coupled with the gradual removal of 350 mg L-1 Zn (5.4 mmol L-1). Decreased delta13CDIC values from -3 per thousand to as low as -12 per thousand indicated that sulfate reduction was coupled with organic carbon oxidation. In the pulp waste cell the most dramatic change was observed near the interface between the pulp waste amended tailings and the underlying undisturbed tailings. Sulfate reduction rates were 5000 mg L-1a-1 (52 mmol L-1a-1), Fe concentrations decreased by 80-99.5% (148 mmol L-1) and Zn was consistently <5 mg L-1. Rates of sulfate reduction and metal removal decreased as the pore water migrated upward into the shallower tailings. Increased rates of sulfate reduction in the pulp waste cell were consistent with decreased delta13CDIC values, to as low as -22 per thousand, and increased populations of sulfate reducing bacteria. Lower concentrations of the nutrients, phosphorus, organic carbon and nitrogen in the woodchip material contribute to the lower sulfate reduction rates observed in the woodchip cell.
对含有不稳定有机碳的活性处理层进行了评估，以确定其在尾矿库中促进硫酸盐还原和金属硫化物沉淀的能力，从而在尾矿废水排放前对其进行处理。将包括木屑和纸浆废料在内的有机碳材料与两个单独试验单元中上部一米的尾矿混合，第三个对照单元仅包含尾矿。在木屑试验单元中，硫酸盐还原速率为500 mg L-1a-1（5.2 mmol L-1a-1），同时350 mg L-1 Zn（5.4 mmol L-1）逐渐去除。δ13CDIC值从-3‰降至低至-12‰，表明硫酸盐还原与有机碳氧化相关。在纸浆废料试验单元中，在纸浆废料改良尾矿与下层未扰动尾矿之间的界面附近观察到最显著的变化。硫酸盐还原速率为5000 mg L-1a-1（52 mmol L-1a-1），铁浓度降低了80 - 99.5%（148 mmol L-1），锌含量始终<5 mg L-1。随着孔隙水向上迁移到较浅的尾矿中，硫酸盐还原和金属去除速率降低。纸浆废料试验单元中硫酸盐还原速率的增加与δ13CDIC值降至低至-22‰以及硫酸盐还原细菌数量增加一致。木屑材料中较低的营养物质（磷、有机碳和氮）浓度导致木屑试验单元中观察到的较低硫酸盐还原速率。
