氧化亚铁硫杆菌对矿山酸矿水中金属污染元素分布的影响

酸矿水是含硫化物矿石在表生条件下与水圈大气圈及微生物相互作用产生的，是环境污染的重要来源．安徽铜陵地区是长江中下游典型多金属矿集区之一，在长期开采过程中产生大量废矿石．地表条件下这些含硫化物的废矿石被氧化，产生对生态环境有严重影响的酸矿水．以鸡冠山矿山为例分析酸矿水中主要微量元素和氧化亚铁硫杆菌的分布特征及相互关系．研究表明，自然酸矿水中存在大量氧化亚铁硫杆菌，酸矿水的形成可能与氧化亚铁硫杆菌的发育有一定联系，氧化亚铁硫杆菌促进酸矿水形成；鸡冠山酸矿水的pH值在2．5～4．2之间，与适宜氧化亚铁硫杆菌生长的酸性条件一致；微量元素在酸矿水中的分布与pH值和氧化亚铁硫杆菌的分布密切相关，在最适宜氧化亚铁硫杆菌生长的pH值3．0左右的酸矿水中微量元素浓度达最低，说明氧化亚铁硫杆菌和酸度对微量元素的分布有一定制约；酸矿水中高度富集微量元素，比河水中溶解态的微量元素含量高出几千倍到几十万倍甚至千万倍．

The Effect of Thiobacillus ferrooxidans on the Distribution of Metal Trace Elements of Acid Mine Drainage Resulting in Environmental Pollution

Acid mine drainage (AMD) is produced by interaction between sulfide ores, water, oxygen in air and bacterium in supergene environment and is a very important cause of serious environmental pollution. Tongling district is one of the clusters of mineralization typical of polymetal deposits in the middle to lower reach of Yangtze River. Large number of waste ores have been produced during long-term mining. Oxidation of the sulfide-bearing waste ores generated AMD harmful to ecological environment. Distribution of trace elements and Tiobacillus ferrooxidans in acid mine drainage and relationship between them in Jiguanshan ore district are investigated in this paper. The studies show that the formation of AMD is related to and promoted by Thiobacillus ferrooxidans, which is identified in AMD samples. Generally, the pH values of AMD range from 2.5 to 4.2 are suitable for growth of Thiobacillus ferrooxidans. The concentrations of trace elements are the lowest in AMD with pH value around 3.0, which is most suitable for growth of Thiobacillus ferrooxidans, implicating that distribution of trace elements are controlled by Thiobacillus ferrooxidans and pH values of AMD. Trace elements, especially heavy metal elements are enriched highly in AMD and their concentrations are thousand to ten million times higher than those dissolved in a river.