Operation Characteristics And Affecting Factors Of Denitrifying Phosphatation Process Fed With Propionic

Acetic acid and propionic acid are the most primary kinds of shot-chain fattyacids in wastewater, and they are both the major carbon sources in differentphosphorus removal processes. It has been verified that propionic is a better carbonsource than acetic acid, however, the research of phosphorus removalcharacteristics was mostly using acetic acid as the substrate, and there were alsodifferent points in wither propionic could promote the phosphorus removalefficiency and the system's stability of denitrify phosphorus removal process or not.So, in this text, we use propionic as carbon source to investigate the maininfluencing factors that influence the ability of phosphorus removal and discuss theconditions of long and steady run in the system of denitrify phosphorus removalprocess, and to analyze the dominant populations and the uptake regulation ofsubstrate.The A/A-SBR system of denitrify phosphorus removal was started-upsuccessfully using propionate as carbon source, the denitrifying phosphorusremoval bacteria became the dominant populations quickly in the system, and thereactor performed well for pollutant removal.The effects of acetic and propionic on the phosphorus removal effective of thesystem were checked. The results obtained demonstrated that propionate couldenhance phosphorus removal effective and maintain the stable statue of thedenitrify phosphorus removal process. Nitrogen and phosphorus and COD can gainbetter removal from the system, and their removal rates are up to 98% and 96% and86% respectively. It indicates that there were 5% more phosphorus removalachieved than acetate did, and the deoxidization of 1mg nitrate may accelerate theabsorption of 1mg phosphorous.The COD, NO3--N and PO43--P removal characteristics of systems of A/O,A/AO and A/A were studied. It was found that, along with the runtime increasing,in the system of A/A-SBR, the removal effect of phosphorus and COD wouldweaken, nitrate would accumulate, and biomass will decease rapidly, as a result theability of phosphorus removal lost obviously. It indicated that, keeping latteraerobic time for 0.5h could gain better phosphorus removal efficiency chronicallyand stably. By the study of the influence of environmental factors on denitrify phosphorusremoval of A/A-SBR, it deduced that carbon source, nitrate, PH and SRT affectingthe stability and efficiency of the system significantly. The optimum conditionobtained for the system in the text is concentration of COD(propionic) is 300mg/L,concentration of NO3--N is 70mg/L, concentration of PO43--P is 18mg/L, SRT is 20d,and latter aerobic time for 0.5h.Changes in microbial community feature, species similarity and communitysyccession were detected by PCR-DGGE, SPSS, SEM and clone techniques, it wasfound that there was a more consistent correlation between microbial communitystructure and the removal efficiency in the system. The change of microbialcommunity structure was one of the main reasons that leading to the removalefficiency decline.In order to study the metabolic models of different pollutants, we analyzed allthe typical cycles of different operation stages, and calculated degradationcharacteristic parameters and corresponding fitting equations. The results providedthe accuracy and reliability of the fitting equations in the denitrifying phosphorusremoval process.