A study on the Treatment of Hydrofluoric Acid Wastewater from Semiconductor Manufacturing Processes and the Possibility of Reuse of reclaimed water

Abstract

Objectives : By eliminating fluorine and other ions through precipitation of fluoride and UF, RO membrane filtration using the hydrofluoric acid wastewater generated from the semiconductor production processes, this study aimed to investigate the possibility of the reuse of the reclaimed wastewater for the processes.Methods : For the experiment, firstly, the 2-stage precipitation of fluoride was done using Ca(OH)2 and PAC and it aimed to judge whether the water quality standards for reuse by each market were satisfied by eliminating colloidal particles and then other metal ions through the UF and RO membrane filtration.Results and Discussion : About 93 % of F- was removed through the 1st and 2nd precipitation. It can be also removed ammonium, phosphate ions, through the UF membrane filtration, about 95 % of particulate matter was removed and finally, the water quality for reuse was satisfied through RO filtration.Conclusion : This study found that the fluorine wastewater generated from the semiconductor production processes can be reused by precipitation and filtration methods without going through the existing complicated treatment methods. In the future, through such treatment procedures, it is expected to be able to secure the reuse of the reclaimed wastewater in the process.