Biological Treatment of Dimethyl Sulfoxide-Containing Wastewater from Semiconductor Industry Using Anaerobic Fluidized Membrane Bioreactor

• Main Authors: Ching-HuaWu, 吳青樺
• Other Authors: Liang-Ming Whang
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/28437b

碩士 === 國立成功大學 === 環境工程學系 === 106 === Dimethyl sulfoxide (DMSO) is a common organic component in semiconductor wastewater, which can be treated by either aerobic or anaerobic biological process. Anaerobic biological treatment, compare to aerobic process, requires lower energy and can recover biogas for further application. Therefore, the purpose of this study is to investigate the feasibility of anaerobic fluidized bed membrane bioreactor (AFMBR) for treating DMSO-containing wastewater. The degradation mechanism of DMSO was evaluated through batch experiments, and the methanogenic community in AFMBR was monitored by terminal restriction fragment length polymorphism (T-RFLP). During the 377 days of operation, AFMBR could maintain a DMSO removal above 99%, however, the decrease in temperature led to the accumulation of dimethyl sulfide (DMS). Under the DMSO loading rate of 0.33 kg m-3 d-1, methane yield of 0.353 L g-1 CODremoved can be achieved with minor production of CO2, DMS, and H2S. The dominant methanogen was Methanomethylovorans spp., which might relate to the DMS degradation. The results from batch experiments show that microorganisms attached on GAC and those in suspended sludge can both degrade DMSO anaerobically, and the higher specific DMSO degradation rate under initial DMSO concentration of 2.4 g L-1 implies the potential of treating DMSO at elevated level using AFMBR. In the batches using DMS, the GAC and suspended sludge had the optimized specific degradation rates of 0.3 mmole h-1 kg-1GAC and 15.6 mmole h-1 kg-1VSS under initial DMS concentrations of 383 mg L-1 and 513 mg L-1, respectively. It was estimated from results of batch experiments that microorganisms on GAC contributed 80% of DMSO degradation and 68-85% of DMS degradation, which is much higher than suspended sludge did. Overall speaking, anaerobic process can effectively remove DMSO from wastewater, but solution for the DMS accumulation under certain conditions is still needed to achieve the complete sulfur removal.