| Summary: | 碩士 === 國立成功大學 === 環境工程學系 === 102 === Due to the amount wastewater of thin film transistor liquid crystal display (TFT-LCD) that increased in Taiwan. The TFT-LCD wastewater was the nitrogen-rich and the composition of them was so complicated that the general microorganisms used difficultly. Therefore, the membrane bioreactor (MBR) combined the activated sludge process with the membrane technology was applied in the TFT-LCD wastewater treatment. In MBR, the soluble microbial products (SMP) and extracellular polymeric substances (EPS)that produced by microorganisms. The SMP and EPS were intercepted by ultrafiltration membrane. The substances called the colloidal COD that cause the COD concentration increased in the aerobic tank. Hence, the aim of this study is analyzed the composition of the colloidal COD and found the accurate relationship between the colloidal COD and nitrification.
The composition of the colloidal COD in two full-scale treatment plant was analyzed by the high performance size exclusion chromatography (HPSEC) and Excitation/Emission Matrix Spectrofluorometer (FEEM). The different molecular weight of organic materials were observed in two full-scale MBR with different nitrification performance. Higher portion of organic compounds were larger than 107 Da in the MBR with bad nitrification. The results show the higher molecular weight of aromatic protein was obvious one of organic compounds to effect nitrification.
Nitrification activity batch experiments were also conducted using sludge from lab-scale MBR systems. The result shows that SMP-like and AP-like materials which might be released from microorganisms could cause bad nitrification.
Thus, organic compounds, or colloidal COD which due probably to long-time operation might influence nitrification performance in membrane bioreactors (MBR) treating TFT-LCD wastewater.
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