Optimization of Landfill Bioreactor Treating Organic Fraction of Municipal Solid Waste

[[abstract]]本研究仍利用中心組合因子實驗設計(Full Factorial Central Composite Design)規劃12 組不同比例之固體廢棄物(OFMSW)及廢棄活性污泥(WAS) 之實驗規模來進行實驗。在37±1℃恒溫培養室進行批次式培養反應後，其 結果再透過反應動力學解析以及反應曲面法(Response Surface Approach)三 度空間之等高線圖推估最大甲烷產生速率(Rs)、最短遲滯期(ë)及最大產生潛 勢(Ps)之OFMSW 與WAS 組合條件。在甲烷產生速率方面可得到，當WAS 量增加時，甲烷產生速率增大，即顯示WAS的添加會影響OFMSW的甲烷 產生速率。其中，WAS 約55g 及OFMSW約65g 之組合時，會有一最小 甲烷速率約40mL/g TVS/day。另外，甲烷產生遲滯期數據顯示，當WAS 及 OFMSW分約為53g 及45g 時，甲烷產生遲滯期最短。同時，WAS 的添加能縮短OFMSW 甲烷化的時間。[[abstract]]The optimal operation of a landfill bioreactor mineralizing organic wastes was investigated using full factorial central design with response surface approach. In this study, the ratio of organic fraction of municipal solid wastes (OFMSW) and waste activated sludge (WAS) were selected as main operational factor on a landfill bioreactor. For this purpose, 120-mL vials were performed as landfill bioreactor simulators.A total of twelve experiments were carried out changing both the initial OFMSW and the initial WAS from 40 to 80 grams. A simple model developed from the Gompertz equation was applied to estimate each individual vial methane production rate, potential and lagphase time, based on their cumulative methane production curves. Through response surface approach, quadratic models for specific methane production potential, rate and lagphase time were fitted and plotted as contour diagrams in order to facilitate examination of experimental results. The contour plots showed that specific methane production rate of landfill bioreactor increased with the increase in the addition of WAS, while a low production rate of 40 mL/g TVS-day was obtained at OFMSW = 65 g and WAS = 55 g. Considering constant lagphase time plotted with OFMSW and WAS, the addition of WAS in landfill bioreactor could stimulate anaerobic mineralization of OFMSW. There would be a shortest lagphase time of 20 days were found at the OFMSW = 45 g and WAS = 53 g filled in the landfill bioreactor simulator used in this study.[[note]]NSC89-2211-E327-00