Treatment of Zn-containing acidic waste water by emulsion liquid membrane process

摘要

Zn-containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.5–5 kV. The zinc concentration of treated waste water was lowered to less than 10 mg • L−1. More than 95% of the zinc was recovered and reused.