Advances in Microbe-Driven Ecological Restoration on Bauxite Residue Disposal Areas.

Ecological restoration and environmental risk control on bauxite residue disposal areas have received persistent attention worldwide as it concerns the sustainable development of global alumina enterprises. Currently, microbially driven ecological restoration has been regarded as a promising way in consideration of its cost effectiveness, lower risks, and durability. However, the extremely degraded environment (e.g., high alkalinity, poor physical structure, and low organic carbon content) poses significant challenges for the activity and effectiveness of functional microorganisms involved in bioremediation. Moreover, the specific mechanisms of functional microorganisms, including alkaline regulation, stable aggregate formation, organic carbon accumulation, and plant growth promotion, in the soil-formation and revegetation process are not well understood, hindering the widespread application of microbially driven ecological restoration strategies in large-scale bauxite residue disposal. To date, these strategies have not been demonstrated in a large scale. To address these gaps, this review focuses on the microbial properties of bauxite residue disposal areas and the limiting factors of microbial functions. Furthermore, considering the differences between bauxite residue and natural soils, the roles of microorganisms in alkaline stabilization, aggregate formation, and organic carbon accumulation in bauxite residue during the soil-formation process are explored. Meanwhile, the microbially driven ecological restoration on bauxite residue disposal areas, including plant growth capacity and restoration process regulation, are discussed. Lastly, future research directions for understanding microbially driven soil-formation processes and ecological restoration on bauxite residue disposal areas are envisaged. This review provides new insights into the driving mechanisms of microorganisms on the soil formation of bauxite residue, offering a theoretical foundation and practical guidance for ecological restoration on bauxite residue disposal areas. [ABSTRACT FROM AUTHOR]