碩士 / 國立成功大學 / 環境工程學系 / 105 / Water, one of the nature resources, is essential for human. In Taiwan, because of the steep terrain and uneven rainfall distribution, available water resource is very low. According to water resources agency, there are three main water consumption sources in Taiwan. One is agriculture consumption (71%), another is domestic consumption (20%), and the other is industrial consumption (9%). Therefore, how to treat these three kinds of wastewater to reach the goal of water reuse is big issue needed for consideration.
Recently, anaerobic process has become popular because of lower energy consumption and fewer waste sludge production. One of the treatment process, known as anaerobic fluidized bed membrane bioreactor (AFMBR), is combined anaerobic fluidized bed (AFB) with membrane bioreactor (MBR). Pilot-scale AFMBR has been successfully used to deal with domestic wastewater, but to treat different kinds of wastewater by AFMBR system still needs more research support. The objective of this study is to investigate the feasibility of pilot-scale anaerobic fluidized bed membrane bioreactor (AFMBR) treating low, medium and high strength of wastewater. These three different strengths of wastewater are shrimp wastewater, TFT-LCD wastewater (supernatant of sedimentation tank), and semiconductor wastewater.
GAC adsorption tests are conducted before using AFMBR to treat wastewater. The results show that after 4.92 days of operation of AFMBR to treat shrimp wastewater, TOC adsorption effect will be carried out and biological effect will be dominant in the rest of operation days. Similarly, after 30.62 days of operation of AFMBR to treat semiconductor wastewater, COD, TOC and DMSO adsorption effect will be carried out and biological effect will be dominant in the rest of operation days.
First, when using AFMBR to treat shrimp wastewater, TOC in the treated white leg shrimp wastewater is about 1 mg C/L, and TOC removal is about 91%. This indicates that the goal of carbon removal in shrimp wastewater by AFMBR is achieved effectively. Additionally, after conducting the denitrification batch experiment, the heterotrophic denitrification can be the mechanism of TOC degradation in shrimp wastewater treatment.
Second, using AFMBR to treat TFT-LCD wastewater, COD removal, total COD removal, and TOC removal are 73%, 92%, and 89%, respectively. In addition, this wastewater contains high molecular weight (about 106 Da) soluble substances, which can be called extracellular polymer or colloidal COD. It also contains soluble microbial by-products-like substances, humic acid-like substances, sulfonic acid-like substances, and little aromatic hydrocarbon protein-like substances. These four types of substances were found in the influent, and there is the decrease of intensity of four types in the reactor and the effluent. Therefore, it is inferred that GAC, microorganisms or membranes in the reactor have the potential to remove these four types of substances.
Third, in the batch experiments of semiconductor wastewater treatment, the sludge from full scale UASB has the potential to degrade DMSO in semiconductor wastewater to produce methane, DMS, and H2S. Additionally, the higher S0/X0 ratio is, the higher specific DMSO degradation rate is. Thus, there is an evidence that there is no inhibition of DMSO degradation by the sludge from full scale UASB. Moreover, when using AFMBR to treat semiconductor wastewater, DMSO removal is 100% in three periods of AFMBR operation. The COD removal and TOC removal can be 95% and 94%, respectively. Finally, there are about 35% of CH4, 57% of CO2, 1% of DMS, and 7% of H2S contained in gas composition of the third period. Furthermore, the mechanism of DMSO degradation in AFMBR is that DMSO are degraded first into DMS, further to MS and finally to H2S. The contribution of GAC and sludge in DMSO removal are 43% and 57%, respectively. This reveals that both of two inoculums almost have the same contribution to degrade DMSO in semiconductor wastewater by using AFMBR. However, the microorganisms attached on GAC produce more methane in AFMBR for the purpose of methane production. And Methanomethylovorans species are the important species to degrade DMSO not only to produce methane, but also to form its by-products, such as DMS, MS, and H2S in this AFMBR system.
At last, it can be found that using AFMBR to treat semiconductor wastewater has potential to not only get good quality of effluent for water reuse, but to produce methane for energy recovery.
| Identifer | oai:union.ndltd.org:TW/105NCKU5515029 |
| Date | January 2017 |
| Creators | Cheng-PinLiu, 劉成彬 |
| Contributors | Liang-Ming Whang, 黃良銘 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 142 |
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