生物薄膜程序處理合成生活污水

Abstract

摘要 一般而言無氧/好氧生物程序有操作簡單、節省能源之特性，但也有許多操作上的瓶頸如污泥膨化、處理水質受污泥沉降性影響極大等。在眾多改良生物處理技術中，生物薄膜程序為一創新與極具發展潛力的新技術，除了解決傳統生物程序所面臨的瓶頸外，更具有可於高污泥濃度下操作，高級處理水質、節省空間、減少污泥產量與耐污染負荷變化等優點。本研究將以無氧/好氧生物程序及無氧/好氧生物薄膜程序作為都市生活污水處理設備，探討其處理效能、優缺點，以作為未來實廠設計與操作之依據。 無氧/好氧生物程序於控制條件下之研究結果顯示，經無氧/好氧生物程序處理之都市生活污水，有機碳、COD、氨氮、有機氮、總氮，其去除率分別91.6%、92.4%、95.7%、72.2%、71.8%以上，此外經沉澱池溢流之出流水懸浮固體物平均濃度為23.4 mg/L，具有穩定處理效果，唯一美中不足的是於提升處理負荷時，即無法穩定操作且有污泥膨化的問題，故仍有操作上的瓶頸。 根據無氧/好氧生物薄膜程序於控制操作條件下之研究結果顯示，於污泥濃度5710-6350 mg/L下提升處理負荷，經無氧/好氧生物薄膜程序處理之都市生活污水，有機碳、COD、氨氮、有機氮、總氮，其去除率分別96.9%、96.9%、93.2%、86.4%、85.7%以上，此外經濾膜過濾之出流水懸浮固體物平均濃度為0 mg/L，且濾膜更具有物理性消毒作用，因此無氧/好氧生物薄膜程序不僅能提升水力負荷縮短水力停留時間至4小時，其處理水質更可符合水回收再利用之水質標準。 在預防薄膜單元阻塞的研究中，當薄膜操作壓力在40 kPa以下時，以間歇式操作薄膜過濾10分鐘加上返沖洗1分鐘， (當薄膜停止過濾時以重力進行返沖洗)能維持薄膜通量於10.6 L/m2-hr穩定操作，並有效預防薄膜阻塞而延長薄膜使用時效。當薄膜操作壓力大於40kPa時，以1.5 wt(%) NaOH (pH10-11)化學藥劑清洗薄膜，則能有效去除薄膜積垢避免薄膜薄膜阻塞更為嚴重。 關鍵詞：無氧/好氧程序、生物薄膜程序、都市生活污水、好氧槽混合液、水力停留時間、物理性消毒、間歇式操作、返沖洗、薄膜積垢。

Abstract In general, Anoxic/Aerobic process (A/O process) is an economical process and useful to remove organic and nutrient from domestic wastewater .However it still has some disadvantages. Numerous of biological treatment technique, membrane bioreactor is a new and creative technique and it improves shortcomings of activated sludge process. High biomass, complete solids removal, a significant disinfection capability, high rate and high efficiency organic matter and nutrient removal, sludge production reduced and be able to endure the variation of contamination are all characteristics of MBR. The investigation on efficiency of domestic wastewater treatment by A/O process and by membrane bioreactor will be used as accordance of full plant design and operation. Under the control, the ivestigation of A/O process reveals that the removal efficiency of TOC, COD, NH3-N, Org-N and T-N is 91.6%, 92.4%, 95.7%, 72.2% and 71.8% respectively. Furthermore, the concentration of effluent suspended solids is 23.4 mg/L. It is effective to treat domestic wastewater but it still has shortcomings on operating. Under the control, the investigation of membrane bioreactor reveals that the removal efficiency of TOC, COD, NH3-N, Org-N and T-N is 96.9%, 96.9%, 93.2%, 86.4% and 85.7% respectively. Furthermore, the concentration of effluent suspended solids is 0 mg/L and membrane provides a significant disinfection capability. The quality of the treated water from membrane bioreactor is so high that recycling and reuse is often a viable option. The investigation of preventing membrane fouling produced, when the membrane operating pressure under 40 kPa, It is useful to make membrane clean by physical backwash with gravity. And when the membrane operating pressure up to 40 kPa, It is useful to make membrane clean by chemical washing with 1.5 wt (%) NaOH (pH10-11) Key words：anoxic/aerobic process, membrane bioreactor, domestic wastewater, mixed liquid, hydraulic retention time, physical disinfection, intermittent operation, backwash, membrane fouling