TitleTSMC Develops Hydro Fluoric Acid Wastewater Membrane Bioreactor System to Reduce Average COD Concentration to 120ppm

TSMC continues to invest in innovative water pollution prevention measures. For organic wastewater containing hydrofluoric acid in the semiconductor process, TSMC has improved machine emission parameters through distribution tracking and while building a dedicated biological treatment system. In September 2021, we successfully reduced average Chemical Oxygen Demand (COD) concentration at Fab 18A from 150ppm to 120ppm. The Company continues to improve green manufacturing technology to mitigate the potential impact on environment resulting from operations.

Tracking Distribution in High-concentration Organic Matter Processes to Reduce COD Discharge Concentration over 90%

Semiconductor process technology continues to advance, stimulating demand for organic compounds as well as increasing COD levels in effluents. To improve water quality, TSMC has designed a distribution tracking system to collect advanced organic wastewater (AOR) and monitor equipment that emit high-concentration organic compounds. TSMC has been able to reduce COD concentration by more than 90% through spontaneously adjusting organic compound emission parameters on equipment. As organic wastewater from semiconductors requires a more complex biological treatment than regular organic wastewater, TSMC has assigned a dedicated team and allocated resources to build a membrane bioreactor system specifically for semiconductor manufacturing to further reduce COD levels, so as to achieve environmental sustainability.

Developing Hydro Fluoric Acid Wastewater Membrane Bioreactor System to Reduce Average COD Discharge Concentration to 120ppm

The membrane bioreactor system is a key technology to process organic wastewater; however, the system is of immense size, and the process faces problems such as clogging from biological thin films as the organic wastewater from semiconductor fabrication contains hydrofluoric acid. In light of these problems, TSMC has been working to develop a membrane bioreactor system suitable for semiconductor manufacturing. High-concentration organic wastewater sources are first identified and channeled into the membrane bioreactor system to reduce the size of the system and ensure the system can be placed within fabs. Organic wastewater containing hydrofluoric acid will undergo reverse osmosis to increase fluoride ion levels, increase efficiency gain with calcium fluoride, and contain calcium carbonate levels (water hardness) below 300 ppm. An automatic thin film pickling device is also designed so that bacteria can adhere to the permeable membrane for better performance, reduced clogging, and water recycling.