經過多年的研究，連續流循序回分式活性污泥系統在自動監測控制系統的發展上，在即時監測控制好氧相及缺氧相的操作時間已有不錯的成果，可達到節省操作時間及提高處理效率的目標。然而目前對於好氧相曝氣量提供方式仍然採取固定曝氣量供給方式，長期操作下，往往造成系統處理成效及污泥沉降性不佳的情形。是故，研擬曝氣控制策略以提昇CFSBR系統整體效率及效益，為現階段發展CFSBR自動監測控制系統的主要工作。此曝氣控制策略主要依據僅提供系統所需氧量的基本原則下，根據溶氧質量平衡關係式，建立曝氣量控制的方法。而此方法得以進行操作，必須根據系統的溶氧轉換率及需氧量的監測資訊回饋控制，故本研究在於建立一線上量測溶氧轉換率、需氧量的方法，以期能應用於好氧相曝氣控制上。由研究結果指出，線上即時量測溶氧轉換率可以判斷出好氧相微生物開始利用系統溶氧的時機，更進一步可以計算出微生物用氧量的多寡。而溶氧轉換率也可以反應出在低溶氧環境下，系統溶氧濃度的微量變化，其累積量更可以模擬出系統溶氧變化的趨勢，可作為使系統溶氧濃度維持穩定的曝氣量修正因子。線上即時量測需氧量的變化可以反應出CFSBR系統氧化態物種的多寡及氧化程度，反應出系統進行硝化反應的型態。進一步應用於輔助判斷好氧相操作終點。且可根據即時量測需氧量的大小，調整曝氣量的多寡，達到節省曝氣能源的目的。 As a simple and compact wastewater treatment system, the continuous-flow sequencing batch reactor (CFSBR) is capable of removing the organic carbonaceous materials, nitrogen and phosphorus biological nutrients by cycling anaerobic, aerobic, anoxic, settling and discharge phases. Therefore, it is suitable to be a water pollution control facility in remote areas and communities without sewer services, especially in Taiwan. Automation is the optimal procedure for increasing the performance of a wastewater treatment system. Since the nitrifying bacteria and phosphorus accumulating organisms have been recognized as obligatory aerobic bacteria, the aerobic phase of CFSBR was usually controlled under high DO level conditions by fixed aeration densities for eliminating the substrate (ammonia nitrogen and oxygen) competitions with other heterotrophic bacteria, and by the ORP/pH real-time control approaches to ensure the performances of biological nitrogen removal. However, these control approaches always led to poor stability of biological phosphate removal, sludge bulking and highly aeration costs. Therefore, developing an aeration control approach for increasing the comprehensive performance of CFSBR is the critical point in the monitoring and control system development. Since there are two monitoring parameters, oxygen transfer ratio and oxygen demand, have to determined in this developed aeration control approach for feedback control the aeration flow rates. The purpose of this study is to establish the on-line oxygen transfer ratio and oxygen demand measuring approach for developing the aeration control approach in practically. The study results revealed that the oxygen transfer ratios and oxygen demands could be measured. The oxygen transfer ratios could respond the trace variations of DO contents in system and to simulate the profiles of DO. Real-time calculating the accumulative values of oxygen transfer ratio could be applied to modify the aeration flow rates to maintain a specific range of DO contents for estimating the oxygen demands. The variations of on-line oxygen demand monitoring values could indicate the oxidation degrees of system and identify the type of nitrification, which also could be applied to determine the aeration flow rates and control points of aerobic phase of CFSBR.
