Professor, Department of Environmental Engineering, National Cheng Kung University

Speech Title: Biological treatment of DMSO-containing wastewater from semiconductor industry under aerobic and methanogenic conditions

Abstract: This study evaluated biological treatment of dimethyl sulfoxide (DMSO)-containing wastewater from semiconductor industry under aerobic and methanogenic conditions. Using an aerobic membrane bioreactor (MBR) treating DMSO-containing wastewater, influent DMSO concentration as higher as 1500 mg/L did not inhibit DMSO degradation efficiency. The results of real-time PCR indicated that abundance of Hyphomicrobium sp. and Thiobacillus sp., potential DMSO and DMS-degrading mircroorganisms, decreased at higher DMSO conditions. Under methanogenic conditions, a higher initial substrate-to-biomass (S/X) ratio inhibited specific DMSO degradation rate, especially at DMSO concentrations higher than 3000 mg/L. For the methanogenic community analyses, it was found that Methanomethylovorans, Methanosarcina, and Methanolobus zinderi were all contributed to methanogenic DMSO degradation. It was also found that DMS accumulated during methanogenic DMSO degradation. Based on the results of terminal restriction fragment length polymorphism analysis, microbial community of methanogens, responsible for DMS degradation, was important to convert DMS to H2S.