酸性矿山排水污染的水库水体酸化特征

矿业开发产生的酸性排水导致下游水体酸化,严重破坏水域生态平衡.以受酸性矿山排水(Acid Mine Drainage,AMD)影响的水库水体为研究对象,通过对水库表层水、界面水和沉积物孔隙水中水质参数的变化进行分析,探讨水库水体酸化特征.结果表明:表层水、界面水pH分别为3.22～3.38和2.70～3.02,水库上覆水体严重酸化,沿沉积物剖面向下酸化程度逐渐减弱;上游AMD在水库水体中存在自然净化过程,而表层沉积物可再次提高上覆水体酸度;沉积物孔隙水ρ(SO42-)极高(0.29～11.85 g/L)且在垂向剖面上变化波动较大,可能与沉积物中次生矿物的形成转化、季节及其他外界条件的变化有关.

Acidification Characteristics of Reservoir Water Polluted by Acid Mine Drainage

Acid mine drainage(AMD) causes acidification of downstream water and seriously breaks the aquatic ecological equilibrium.Taking a reservoir affected by AMD as a study object,the acidification characteristics of the reservoir water were discussed by analyzing the variation of water quality parameters of the surface water,interfacial water and sediment pore water.The results show that the overlying water in the reservoir was seriously acidified,with pH values of 3.22-3.38 and 2.70-3.02 for the surface water and the interfacial water respectively.The pH vertical profile of core samples showed that the effect of acidification on the sediments was gradually weakened with depth.There was a natural purification of AMD from upstream presented in the reservoir.However,the surface sediment increased the acidity of the overlying water.The contents of SO42-in sediment pore water were very high,with a range of 0.29-11.85 g /L.The vertical variations of SO42-content were larger,which may relate to the formation and transformation of secondary minerals,seasonal changes and other natural condition changes during the deposition processes.