Copper immobilization and resource recovery from acidic copper mine water based on algae and bioelectrochemical system.

Acidic copper mine water, characterized by its organic matter scarcity, low pH, and high Cu2+ pollution, presents major challenges due to limitations in traditional biological treatment and the high costs of physicochemical methods. There is an urgent need for an efficient treatment and resource recovery process. Algae could adsorb and immobilize Cu2+, and the secondary metabolic organics could be metabolized by bacteria, which compensates for the shortcomings of algae. Enhanced by the metabolic advantages of algae and bacteria, coupled with efficient electron transfer and ion migration, the algal bioelectrochemical system (ABES) significantly improves Cu2+ immobilization and recovery efficiency. These offer promising pathways for establishing a "low-cost, harmless, and resource-oriented" mine water treatment system. This study systematically reviews the mechanisms and key influencing factors behind the Cu2+ immobilization and recovery processes in algae and ABES. It highlights the technological features and limitations of these systems while addressing current technical bottlenecks. Future research directions are explored, including selective Cu2+ recovery, integrated treatment of sludge and wastewater.