A sustainable development approach of silica recovery and treatment of semiconductor-industry wastewater using ceramic membranes
Yogadevan Vijayan, Yeit Haan Teow, Maha Mohammad AL-Rajabi, S. Ranil Wikramasinghe
Abstract
The semiconductor sector generates a large amount of wastewater. If these wastewaters are not treated, they can be harmful to the environment. Wastewater often contains silicon particles, which could be recovered and repurposed. Membrane technology has grown significantly and offers benefits in treating wastewater. The objective of this study is to evaluate the performance of ceramic membrane as a sustainable development approach of silica recovery for the treatment of semiconductor-industry wastewater. Two ultrafiltration (UF) ceramic membranes with different molecular weight cutoff were used in this study. UF membrane with pore diameter smaller than hydrodynamic particle size of the silica colloids (124.3 nm to 126.7 nm) was able to recover silica colloids. Membrane B has the best performance in terms of color rejection (98.95%), SS rejection (97.76%), TDS rejection (92.75%), NH3-N rejection (92.86%), turbidity rejection (99.53%), COD rejection (99.34%), and BOD rejection (93.75%). Besides, the usage of 0.1 M NaOCl for alkaline cleaning was most prominent in membrane cleaning with a high FRR value (78.39–80.77%). Furthermore, the blocking mechanisms were determined, as proven by the Hermia model, which is standard blocking for both membranes. This innovation serves as a new revolution in semiconductor-industry wastewater treatment where wastewater treatment process comes along with simultaneous recovery of silica for recycle and reuse.