重庆西部干旱区煤矿矿井水水质综合评价

Comprehensive assessment of coal mine drainage quality in the arid area of Western Chongqing

为了提高重庆西部干旱区煤矿矿井水综合利用水平,缓解该区居民用水严重短缺状况,必须对该区的矿井水水质进行综合评价研究。利用Aq.QA水化学软件和模糊综合评价法对重庆西部干旱地区煤矿矿井水、矿区饮用水和水库水体的水质特征进行了综合评价,并结合煤矿地层特点对矿井水水质成因进行了分析。研究结果表明:91%的矿井水水化学类型为Cl-Na型,矿区饮用水和水库水样均为SO4-Ca型;矿井水中共有9个离子超过国家生活饮用水标准的限制,其中Cl-,Na+和Fe离子超标情况最为严重;矿井水中较高含量的Fe离子来自须家河组地层内菱铁矿结核的溶解,而严重超标的Cl-和Na+可能来自于须家河组地层部分地段岩盐的溶解;10个V级水质的矿井水包括4个微咸水、3个咸水和1个盐水水样,2个矿区饮用水为Ⅲ级水质淡水,2个水库水样和广顺县城饮用水为I级水质;模糊综合评价法能够准确评价不同类型的水体,且能揭示每个水体的主控污染因子,但无法对矿化度大于1 000 mg/L的水体进行深度评价。

In order to raise the utilization level of coal mine drainage and alleviate domestic water shortages in the arid area of Western Chongqing, water quality of coal mine drainage in this district must be comprehensively evaluated. Wa- ter quality of coal mine drainage, mine drinking water and reservoir water were comprehensive evaluated by Aq. QA water chemistry software and fuzzy comprehensive evaluation method. The results show that hydrochemistry type of 91% mine drainage are C1-Na type,mine drinking water and reservoir water are SO4-Ca type. There are 9 ions in mine drainage over the national standard of drinking water limit, and the degree of exceed the standard for CI-, Na＋ and Fe ions are most serious. The high content Fe ion in mine drainage is derived from dissolution of siderite concre- tion in the Xujiahe formation, and dissolution of rock salt in the Xujiahe formation may cause the high content of C1- and Na＋ ions in mine drainage. Ten mine drainage of V grade water quality includes four brackish water, three salt wa- ter and one brine. Two mine drinking are Ⅲ grade freshwater, and two reservoir water and one drinking water of Guan- gshun country are I grade freshwater. Fuzzy comprehensive evaluation method can evaluate different types water accu- rately, and reveal the main pollution factors of every water. Hovever, fuzzy comprehensive evaluation method can＇ t fur- ther evaluate the mine drainage with salinity over 1 000 mg/L.