Inhibition of Acid-Mine-Drainage Formation in Mine Environments and Remediation of Acid Contaminated Sites

黄铁矿和黄铜矿的风化作用在酸性矿山废水的形成中起着重要作用，并从矿物中释放出镍、钴、锌、砷等有毒微量元素。在矿山环境中，特别是在有氧环境中，铁和硫氧化细菌加速了黄铁矿和黄铜矿的风化。本研究从风化机理、细菌抑制剂和酸污染场地修复三个方面进行了研究。在酸性溶液中，铁优先溶解，形成富硫表层。天然有机酸，如单宁酸、木醋、黄腐酸和腐植酸，抑制了微生物介导的黄铁矿溶解。这是由于天然有机酸在黄铁矿表面的吸附、细胞生长的抑制以及Fe(III)离子的还原和络合作用造成的。在常温空气中的硫酸溶液中，亚铁离子促进了黄铜矿与溶解氧的氧化，从而促进了铜的提取。然而，铁氧化细菌会消耗亚铁离子，从而抑制铜的提取。十二烷基硫酸钠和单宁酸不仅能抑制细菌亚铁的氧化，还能抑制黄铜矿与溶解氧的氧化，从而抑制铜的提取；十二烷基硫酸钠的存在抑制了铁氧化细菌对高硫煤渣中铁的溶解，抑制了细胞的生长。然而，垃圾中含有一些可以释放到排水系统中的可溶性铁物种。对于降低排水含铁量，添加石灰是有效的。

Weathering of pyrite and chalcopyrite plays an important role in formation of acid mine drainage and releases toxic trace elements, such as Ni, Co, Zn and As from the minerals. In mine environments, and especially in aerobic environments, the pyrite and chalcopyrite weathering is accelerated by iron- and sulfur-oxidizing bacteria. This research was conducted on the weathering mechanism, inhibitor to the bacteria and remediation of acid contaminated sites.In acid solutions the preferential dissolution of iron took place resulting in the formation of a surface layer enriched with sulfur. Natural organic acid, such as tannic acids, wood vinegar, fulvic acids, and humic acids, suppressed microbially mediated dissolution of pyrite. It was caused by adsorption of natural organic acids on pyrite, inhibition of cell growth, as well as reduction and complexation of Fe(III) ions.Ferrous ions enhanced copper extraction in sulfuric acid solutions in air at ambient temperatures because they promoted chalcopyrite oxidation with dissolved oxygen. However iron-oxidizing bacteria consumed ferrous ions, suppressing copper extraction. Sodium lauryl sulfate and tannic acid suppressed not only the bacterial ferrous oxidation but also the chalcopyrite oxidation with dissolved oxygen, resulting in a suppression of copper extraction.Dissolution of iron from high sulfur coal refuse by iron-oxidizing bacteria was depressed in the presence of sodium lauryl sulfate, which inhibited cell growth. However, the refuse contained some soluble iron species that could release into drainage. For decreasing iron concentration of drainage addition of lime was effective.