One-Step Recovery of Reusable Tetramethylammonium Hydroxide from Waste Photolithographic Developer by Electrodialysis

Large quantities of waste developer solution containing a high concentration (mass fraction) of tetramethylammonium hydroxide (TMAH) are generated in electronics manufacturing, which poses significant threats to the ecological environment and human health. Traditional methods (e.g., biochemical degradation, high-temperature incineration) suffer from severe resource waste, high energy consumption (>10 kWh/kg), and secondary pollution (e.g., NO x emissions), failing to meet the demands of the circular economy. To address these challenges, this study proposes a two-compartment electrodialysis (ED) process for TMAH recovery, evaluating the effects of key parameters (current density: 5.35–10.70 A/m 2; concentration degree; membrane type: AMT vs AHA) on recovery efficiency, current efficiency, and energy consumption. Under optimal conditions (AMT membrane, current density 5.35 A/m 2, waste-deionized water volume ratio 1:2.33), the process achieved a minimum energy consumption of 2.245 kWh/kg, with recovered TMAH concentration after enrichment reaching 2.38 wt % (meeting industrial reuse standards). Preliminary economic evaluation shows that the total recovery cost is 0.311 United States dollar (USD)/kg, far lower than traditional treatment (>1.2 USD/kg) and commercial TMAH price (5–10 USD/kg), providing a cost-effective and eco-friendly solution for TMAH recycling in the electronics industry.