利用AFBR-AFMBR系統處理台灣低濃度生活污水

Abstract

相較於傳統好氧活性污泥法處理污水，厭氧生物處理不僅耗能少還具有產生能源的潛力，因此，已被廣泛應用於處理不同種類的廢水。然而，厭氧生物處理啟動時間較長是其缺點之一，成為限制其實廠化的主要限制因素。本研究利用高效率厭氧流體化床反應槽結合厭氧流體化薄膜反應槽 (AFBR-AFMBR) 在室溫下處理都市污水，目的在探討利用沸石作為載體所需的啟動時間及反應槽表現，及評估利用此系統處理低濃度生活污水之可行性。本研究以1000 mg COD/L合成廢水、水力停留時間 (HRT) 為1 d、有機負荷率 (OLR) 為1 g/m3/d，以半連續模式操作啟動階段。系統操作到第32天，pH值維持在7，化學需氧量 (COD) 去除效率達90％以上，穩定後的產氣量為1 L/d，顯示系統已達穩定。且揮發性懸浮固體物濃度 (VSS) 從100 降至10 mg/L。另外，在室溫 (20 to 35oC) 連續模式操作下處理低濃度真實污水 (73 to 220 mg COD/L)，總化學需氧量去除率達70到90%、總懸浮性固體物去除率達96%及0.13 L CH4/g CODremoved之比甲烷產量。且薄膜在薄膜通量10 LMH下操作333天，不須經化學清洗。除此之外，系統所需之總能量僅0.015 kWh/m3，又產生之甲烷可提供能量約0.0024 kWh/m3。以上結果皆顯示厭氧流體化床反應槽結合厭氧流體化薄膜反應槽 (AFBR-AFMBR) 能成功應用在處理低濃度生活污水。

In the present study, an anaerobic fluidized bioreactor combined with an anaerobic fluidized membrane bioreactor (AFBR-AFMBR) was used to for treat municipal wastewater at ambient temperature. The objectives of this study were to evaluate the start-up time and the performance using zeolite as carriers and the performance of the AFBR-AFMBR. During the start-up period, the reactor system was operated in semi-continuous mode and at a hydraulic retention time (HRT) of 1 d and an organic loading rate (OLR) of 1 g/m3/d with influent chemical oxygen demand (COD) of 1000 mg COD/L (made by synthetic wastewater). The reactor system reached to steady state with a pH level of 7, COD removal efficiency higher than 90% and 1 L/d of the steady biogas production. The microorganisms were successfully attached onto the carrier. Thereafter, the reactor system was changed to continuous mode operation at 3.5 h of total HRT for treating municipal wastewater (73 to 220 mg COD/L) at ambient temperature ranged from 20 to 35oC. The reactor performance reached to 70 to 90% of COD removal, 96% of total suspended solids (TSS) removal and 0.13 L CH4/g CODremoved of specific methane production. The membrane module in AFMBR can be continuously used for 333 d at a flux of 10 LMH without chemical cleaning. Besides, the reactor system only needed 0.015 kWh/m3 of pumping energy requirement and can generate 0.0024 kWh/m3 of methane energy. The above results revealed that the AFBR-AFMBR is a high efficiency energy-saving system for treating municipal wastewater.