Renovation of a failed constructed wetland treating acid mine drainage
Renovation of a failed constructed wetland treating acid mine drainage
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处理酸性矿山排水失败的人工湿地的修复
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
A. Karathanasis
中科院分区：
文献类型：
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作者：
C. Barton;A. Karathanasis
摘要美国肯塔基州麦克里里公司的 酸性矿山废水严重损害了美国肯塔基州琼斯分水岭的水质。1989年，为了减少AMD的影响，建造了1022平方米的表面流湿地，但由于处理区利用不足、碱度生产不足和金属超载，该系统在6个月后失败。为了提高处理效率，设计了一个改造项目，其中包括两个缺氧石灰石排水系统(ALDS)和一系列厌氧地下排水系统，这些排水系统促进了矿井水的垂直流动，通过由有机堆肥覆盖的石灰岩床连续产生碱度系统(SAPS)。翻修后19个月的分析结果非常令人鼓舞。平均铁浓度从787 mg L-1降至39 mg L-1，pH值从3.38升至6.46，酸度从2244降至199 ppm mg L(相当于碳酸钙)。在研究期间，铝、铁、酸度、硫酸盐和锰的平均质量去除效率分别为98%、95%、94%、55%和49%。结果表明，石灰石溶解产生的碱度增加和较长的停留时间有助于充分的缓冲和金属保留。在翻修中使用的ALDS和SAPS技术的组合以及它们在湿地系统中的实施顺序被证明是处理这种和其他高金属负荷AMD来源的适当和非常有前途的设计。
Abstract Acid mine drainage (AMD) from abandoned underground mines significantly impairs water quality in the Jones Branch watershed in McCreary Co., Kentucky, USA. A 1022-m2 surface-flow wetland was constructed in 1989 to reduce the AMD effects, however, the system failed after six months due to insufficient utilization of the treatment area, inadequate alkalinity production and metal overloading. In an attempt to improve treatment efficiencies, a renovation project was designed incorporating two anoxic limestone drains (ALDs) and a series of anaerobic subsurface drains that promote vertical flow of mine water through a successive alkalinity producing system (SAPS) of limestone beds overlain by organic compost. Analytical results from the 19-month post-renovation period are very encouraging. Mean iron concentrations have decreased from 787 to 39 mg l–1, pH increased from 3.38 to 6.46 and acidity has been reduced from 2244 to 199 mg l–1 (CaCO3 equivalent). Mass removal rates averaged 98% for Al, 95% for Fe, 94% for acidity, 55% for sulfate and 49% for Mn during the study period. The results indicate that increased alkalinity production from limestone dissolution and longer residence time have contributed to sufficient buffering and metal retention. The combination of ALDs and SAPS technologies used in the renovation and the sequence in which they were implemented within the wetland system proved to be an adequate and very promising design for the treatment of this and other sources of high metal load AMD.