The discharge, recovery, and reuse treatments of integrated circuit industry wastewater

Integrated circuit industry is a strategic, fundamental and pilot industry that supports economic and social development. It has high water consumption and drainage. The quality characteristics of integrated circuit wastewaters were classified, including ammonia wastewater, fluorine wastewater, acid and alkali wastewater, organic wastewater, copper wastewater, and grinding wastewater. The treatment processes and technologies of up-to-standard discharge, pollutant resource recovery, and water reuse treatment of wastewater containing different pollutants were summarized. The physicochemical processes for up-to-standard discharge treatment included coagulation sedimentation, filtration and adsorption to treat fluorine-containing, copper-containing and grinding wastewater, and biochemical processes included hydrolytic acidification, internal circulation anaerobic reactor, AO, and membrane bioreactor to treat ammonia-containing and organic wastewater. Advanced oxidation and electrolysis technology received much attention in recent years. The resource recovery technologies for pollutants such as fluorine, copper and tetramethylammonium hydroxide in wastewater included ultrafiltration and electrodialysis. Wastewater reuse treatment technologies and processes included coagulation sedimentation, membrane bioreactor and filtration. Reverse osmosis was the core of wastewater reuse treatment, with the goal of producing industrial pure water for integrated circuit manufacturing. Finally, the problems faced in wastewater treatment were discussed. Corresponding control methods were suggested: improving the collection system, strengthening the removal of heavy metals and refractory organic pollutants to reduce the biological toxicity of wastewater, and using pretreatment, fouling monitoring, membrane cleaning, and developing new membrane materials methods to control reverse osmosis membrane fouling.