Bipolar Membrane Electrodialysis: A Strategy for Wastewater Treatment and Resource Recovery

Bipolar electrodialysis (BPED) is a well-established membrane-based separation technique for treating process waters. A primary advantage of BPED is its ability to generate two valuable products, acid and base, while enabling near-complete desalination. This study investigates the use of BPED to remediate process waters from (i) battery recycling operations containing lithium and (ii) hydrometallurgical operations containing low-value salts, specifically sodium sulfate. For battery recycling wastewater, the goal is to recover lithium as battery-grade lithium hydroxide. For sodium sulfate-rich process water, the goal is to produce sodium hydroxide and sulfuric acid suitable for reuse in the hydrometallurgical process. The impacts of key operating parameters and the challenges associated with BPED implementation are discussed.