| 摘要: | 近年來新規劃的污水處理廠多採用可同時去除氮、磷的生物處理系統，再結合薄膜生物反應系統(Membrane Bioreactor，以下簡稱MBR)，目的即在使處理後的放流水可作為再生水使用，在生物處理單元的去氮除磷環境如何與MBR系統搭配控制，其與傳統二沉池的污泥迴流有何不同，將為本研究的探討重點。
本研究以桃園某污水處理廠6,000噸的改良A2O+MBR處理系統為對象，進行實廠動態進流條件下厭氧槽、缺氧槽、好氧槽(內置MBR)串聯操作的相關水質變化與控制條件研究，並對各項水質之污染負荷進行處理效率探討。
研究結果顯示在A2O系統僅有硝化作用而幾乎無脫硝作用，總磷幾乎無去除率；在MBR系統中懸浮固體、BOD5與COD的去除率非常顯著，去除率高達99 %以上，同時MBR薄膜也具有去除氨氮與總磷的功能，去除率平均為36.57 %與74.10 %，處理後的回收水中溶解性固體物平均為292.20 mg/L，顯示水中鹽類或金屬離子無法被MBR薄膜分離去除；以改良A2O+MBR全系統來看，整體進、放流水質的懸浮固體、BOD5與COD平均去除率分別為97.45 %、95.57 %、92.79 %，不會因好氧池MLSS濃度變化而影響去除率，氨氮處理後平均為3.57 mg/L，整體去除率平均為85.68 %，其可在好氧環境中因足夠的溶氧使硝化作用完全，亦不會因好氧池MLSS濃度變化而影響，而以改良A2O+MBR系統處理總磷可被污泥攝取與儲存的濃度有限，經排泥後總磷含量可下降但效果有限，此因硝化液及迴流污泥皆來自於MBR薄膜槽，薄膜槽需要曝氣以保持膜絲擾動，使得回流至前端厭氧槽與缺氧槽的污泥由於MBR薄膜槽中過高溶氧導致脫硝與釋磷作用不顯著。;In recent years, many sewage treatment plants incorporate biological processes which can remove phosphorus and nitrogen simultaneously. In order to reclaim treated water, membrane bioreactor systems (MBR) are further included. How to control the nitrogen and phosphorus environment and biological treatment units with MBR process ? And what is the different with the traditional secondary settling tank return sludge, will be the focus of this study.
In this study, 6,000 tons of modified A2O + MBR system were used to study the changes of water quality and control conditions of anaerobic tank, anoxic tank and oxic tank (built-in MBR) in real flow conditions, discussion on the treatment efficiency of pollution load.
The results show that the A2O system only nitrification and almost no denitrification, total phosphorus almost no removal rate; The removal rate of BOD5 and COD was very significant in the MBR system, and the removal rate was above 99 %. At the same time, the MBR had the function of removing ammonia and total phosphorus, the average removal rate was 36.57 % and 74.10 %, the average of total dissolved solids were 292.20 mg/L, indicating that the salt or metal ions in the water could not be separated by the MBR; In modified A2O + MBR system, The average removal rate of suspended solid、BOD5 and COD was 97.45 %、95.57 % and 92.79 %, and the removal rate was not affected by the concentration of MLSS in the oxic tank. After treatment, the average removal rate of ammonia was 3.57 mg/L, and the average removal rate was 85.68 %. The nitrification could be carried out in oxic environment due to sufficient dissolved oxygen. Total phosphorus is limited by the concentration of sludge uptake and storage, and the total phosphorus content after sludge discharge can be reduced but the effect is limited. The nitrification sludge and the return sludge are all from the MBR tank, the membrane tank needs aeration to keep the membrane swing, so that when the sludge back to the anaerobic tank and the anoxic tank, due to the dissolved oxygen of sludge is too high lead to denitrification and phosphorus release is not significant. |
