Abstract

Bauxite residue is the by-product produced by Bayer’s process, the main industrial extraction process of aluminum. The currently estimated deposit of bauxite residue is about 3 Gigaton which is increasing every year by 120 Megaton. It is characterized by high pH, salinity along with the presence of many heavy metals and radioactive elements and is the main source of environmental pollution. Due to the absence of any prominent reuse option rehabilitation of bauxite residue disposal site is of primary concern. However, management and remediation by physico-chemical methods are neither economically viable nor environment friendly. This bauxite residue harbors functionally and genetically diverse indigenous microbial communities which have been studied by both culture-dependent and metagenomic approaches. These extremophilic microbiota has not only adapted to hostile environment but also play a critical role in the biogeochemical processes. Attempts have been initiated to assess the potential of these microbial resources for possible application in bioamelioration, bioremediation, and bioleaching of metal values from bauxite residue. Implementation of these technologies however demands success in both pilot-scale and field-level experimentations. This review will provide updated information on microbial resources of bauxite residues and their potential role in the bio-management of this unique environment.

摘要

铝土矿渣是拜耳法生产的副产品，拜耳法是铝的主要工业提取工艺。目前估计的铝土矿残渣储量约为 3 吉吨，每年增加 120 兆吨。它的特点是pH值高、盐度高，同时存在许多重金属和放射性元素，是环境污染的主要来源。由于没有任何突出的再利用选择，铝土矿残渣处置场的修复是首要关注的问题。然而，通过物理化学方法进行管理和修复既不经济也不环保。这种铝土矿残留物具有功能和遗传多样性的本土微生物群落，这些微生物群落已通过培养依赖性和宏基因组学方法进行了研究。这些极端微生物群不仅适应了恶劣的环境，而且在生物地球化学过程中发挥着关键作用。已经开始尝试评估这些微生物资源在生物改良、生物修复和生物浸出铝土矿残渣中的金属价值的潜在应用。然而，这些技术的实施需要在中试规模和现场试验中取得成功。本综述将提供有关铝土矿残渣微生物资源及其在这一独特环境的生物管理中的潜在作用的最新信息。从铝土矿残渣中生物浸出有价金属。然而，这些技术的实施需要在中试规模和现场试验中取得成功。本综述将提供有关铝土矿残渣微生物资源及其在这一独特环境的生物管理中的潜在作用的最新信息。从铝土矿残渣中生物浸出有价金属。然而，这些技术的实施需要在中试规模和现场试验中取得成功。本综述将提供有关铝土矿残渣微生物资源及其在这一独特环境的生物管理中的潜在作用的最新信息。