Automatic Monitoring and Real-time Control of Modified Single Continuous-flow Sludge Batch Reactor System--Using ORP, pH as Control Parameters

• Main Authors: Chen, Wan-Yuan, 陳萬原
• Other Authors: Liaw Shu-Liang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/90285682749327303620

碩士 === 國立中央大學 === 環境工程學系 === 84 === For open and dynamic systems, the conventional steady- state control strategies applied in wastewater treatment plants usually could not result in the best performance. From recent research results, it has been found that the breakpoint of the ORP and pH monitorning curves of biological treatment processes are correlated to the disappearance of nitrogen compound. Therefore, a real-time control strategy built by ORP and pH was used to control the single tank continuous- flow SBR in this study. The experimental procudures of this study contain two main sections as follows: (1) Fixed-time control study: to prove the feasibility of using ORP and pH as the control parameters under different operation conditions. Results obtained from fixed-time studies reflect that the ORP and pH profiles can represent the system''s dynamic characteristics, especially in pointing out the ends of nitrification and denitrification in form of breakpoint. It is noted that the locations and values of ORP and pH, on those endpoints, are highly correlated to F/M ratio with linear relationship. This result provided the primary ideas for set-point and set-time control. The breakpoints, set- point and set-time on the ORP and pH profiles were used to establish the real-time control strategy; (2) Real-time control study: some results had found in real-time study including: (a) pH was more appropriate parameter for controlling aerobic stage and ORP for controlling anoxic stage; (b) six mathematical calculation methods were appliced to determine the transfers of operation stages, and the multiplication of two slopes of ORP was appropriate for determining the breakpoint on ORP profile, and the differential of pH was more practical for determining the breakpoint of pH; (c) The real-time control study show a good proformane in COD and nitrogen removeal, approxicaty 93% COD , 88.68% NH4+-N, 86.54% T-N be reducted. In addition, the real-time study required less retention time than fixed-time study, it is approxicately 2.5 hours can be abridged. Thus, it can save the cycle time and aeration energy.