|摘要: ||好氧顆粒(aerobic granules, AG)具結構緊密、沉澱性佳、高有機負荷及耐毒性等特 點。當顆粒大到一定程度，因顆粒內部無足夠氧氣及基質，逐漸進入厭氧或飢餓狀態， 導致顆粒崩解流失。溶氧愈高穿透顆粒內部的深度愈深，依亨利定律，溶氧量隨壓力升 高而提升，本團隊正執行之小產學計畫，以高壓生物反應槽處理食品廢水，發現系統溶 氧可維持在>12mg/L，目前國內外並未有以高壓型態操作AG 報導，因此本研究計畫將 以密閉反應槽於高壓環境下提升飽和溶氧，探討AG 的形成及其特性。 AG 與薄膜結合（AGMBR），除較佳出流水外， AG 取代傳統MBR 中之生物污泥， 可降低薄膜阻塞。但之前AGMBR 研究並沒有顆粒篩選的過程，造成顆粒漸漸崩解。顆 粒篩選及適度排出EPS 是維持污泥顆粒化及AGMBR 穩定之重要步驟。本研究將於高 壓下連續方式操作AGMBR，且加入顆粒篩選機制，討論篩選時機與方法及高壓操作對 AG 特性與薄膜阻塞的影響。 初步研究結果顯示，本計畫所提之高壓方式培養好氧顆粒為極可行方式，高壓系統 顆粒的形成較常壓系統穩定，出流水比常壓系統佳。本研究於三年內將完成高壓下好氧 顆粒污泥之培養與穩定性研究及高壓好氧顆粒薄膜系統之開發。第三年則進行高壓好氧 顆粒污泥系統與高壓好氧顆粒污泥薄膜系統之模廠試驗。|
Aerobic granules (AG) have compact structure and excellent settleability, can be operated at high organic loading, and are resilient to toxicity. When AG grow to certain size, the core of AG is depleted in oxygen and substrates, resulting in anaerobic and famine condition. Subsequently, AG in the reactor are disintegrated and lost. The higher the dissolved oxygen (DO), the deeper the oxygen penetration inside AG. According to the Henry's Law, the concentration of dissolved oxygen is proportion to the oxygen pressure in the gas phase. In our ongoing NSC project titled “Intermittent high pressure sequential bioreactor (IHPSB) with integration of flotation and sand filtration for treating food-processing wastewater”, we found that DO is always higher than 12 mg/L under elevated condition. Currently, no study takes the advantages of high DO under elevated condition for operating AG system. Therefore, we intend to study AG formation and characters under elevated condition. In addition of obtaining good effluent quality, membrane fouling is lesser in integrating AG and membrane biological reactor (AGMBR) than conventional MBR. In previous AGMBR studies, no granule selection process is incorporated in the operation, leading to disintegration of AG. Granule selection process and discharge of EPS is vital for keeping AG intact and maintaining stability of AGMBR. In this proposed study, we will operate high pressure AGMBR under continuous mode with incorporation of granule selection process. The frequency and timing for activation of granule selection process on AG characters and membrane fouling will be discussed. Our preliminary results show that high pressure AG process is much more stable in terms of granule formation and better treated water quality than conventional AG process. We are confident that operating AG process under elevated pressure is a viable and brilliant idea. We propose to study the formation and stability of AG under elevated pressure, to develop high pressure AGMBR system, and to conduct pilot scale study of the proposed systems within a three-year project span.