Chemical precipitation, oxidation/reduction, filtration, ion-exchange, reverse osmosis, membrane technology, evaporation and electrochemical treatment as remediation technologies have various shortcomings which have fueled the search for more environmentally friendly and cost-effective methods of remediating heavy metal contaminated environments. Indigenous bacteria in heavy metal contaminated sites present a possible solution to this concern. This study assessed the potential of indigenous heavy metal resistant bacteria as immobilization agents of Pb, Ni and Zn in Au mine tailings. Tailings from three abandoned Au mining environments; mine tailings A (MA), mine tailings B (MB), and Tudor shaft (TS) were collected and indigenous heavy metal resistant bacteria present in the tailings isolated. The isolated bacteria OMF 532 ( E. asburiae ) and OMF 003 ( B. cereus ) were used in bioaugmenting Ni-, Pb- and Zn-spiked tailings to determine the potential of the isolates to immobilize these metals. The immobilization potential of the isolates as determined by the difference in metal mobility in the tailings samples before and after bioaugmentation was used to assess the immobilization potential of the bacterial isolates. Mobility factor (MF) of Ni in the samples was reduced from 16.4 to 6.2, and 17.6 to 7.4 in MB and MA, respectively, reflecting a 35% decrease in Ni mobility. Lead and Zn mobility in the samples also showed a decrease of 90% and 60%, respectively, after bioaugmentation. Though MF values for Ni, Pb and Zn in the TS samples indicated low level of mobility of these elements at the site, bioaugmentation further reduced their mobility by 25–35% for Ni, 95% for Pb, and 10–30% for Zn. The results of this study show that indigenous bacteria in the tailings have the potential to reduce the bioavailable fractions of the three metals studied in the mine tailing and could be further exploited in heavy metal remediation of the sites. The study investigated the potential of indigenous bacteria to immobilize selected heavy metals in tailings samples. The highlights of the manuscript include the following: The study identified Bacillus cereus OMF 003 and Enterobacter asburiae OMF 532 as heavy metal resistant bacteria in Au mine tailings. Bioaugmenting tailings with the bacterial isolates reduced the mobility Factor of Ni in the samples by up to 35% for Ni, 90% for Pb and 60% for Zn. Indigenous Bacillus cereus OMF 003 and Enterobacter asburiae OMF 532 presents significant opportunities for heavy metal immobilization in tailings contaminated environments.

中文翻译：

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从金矿尾矿中分离出的土著细菌的重金属固定潜力

化学沉淀、氧化/还原、过滤、离子交换、反渗透、膜技术、蒸发和电化学处理等修复技术存在各种缺点，促使人们寻找更环保、更经济的重金属污染环境修复方法。重金属污染场地的本土细菌为这一问题提供了可能的解决方案。本研究评估了本地重金属抗性细菌作为 Au 尾矿中 Pb、Ni 和 Zn 固定剂的潜力。来自三个废弃金矿开采环境的尾矿；收集了尾矿 A (MA)、尾矿 B (MB) 和 Tudor 竖井 (TS)，并分离了尾矿中存在的本地抗重金属细菌。分离出的细菌 OMF 532 (E. asburiae ) 和 OMF 003 (B. cereus) 被用于生物强化 Ni-、Pb- 和 Zn 尖峰尾矿，以确定分离物固定这些金属的潜力。通过生物强化前后尾矿样品中金属迁移率的差异确定的分离物的固定潜力用于评估细菌分离物的固定潜力。样品中 Ni 的迁移率 (MF) 在 MB 和 MA 中分别从 16.4 降至 6.2，从 17.6 降至 7.4，反映出 Ni 迁移率下降了 35%。生物强化后，样品中铅和锌的迁移率也分别降低了 90% 和 60%。尽管 TS 样品中 Ni、Pb 和 Zn 的 MF 值表明这些元素在现场的迁移率较低，但生物强化进一步降低了 Ni 迁移率 25-35%，Pb 迁移率 95%，Zn 为 10-30%。这项研究的结果表明，尾矿中的原生细菌有可能降低尾矿中研究的三种金属的生物可利用部分，并可进一步用于场地的重金属修复。该研究调查了本地细菌在尾矿样品中固定选定重金属的潜力。手稿的重点包括以下内容： 该研究将蜡样芽孢杆菌 OMF 003 和 Enterobacter asburiae OMF 532 鉴定为金尾矿中的重金属抗性细菌。使用细菌分离物对尾矿进行生物强化后，样品中 Ni 的迁移系数降低了 35%（Ni）、Pb 的 90% 和 Zn 的 60%。