Endogenous Respiration Characteristics Of Activated Sludge Biological Quantitative Analysis And Research

Endogenous respiration was an important metabolic process for activated sludgeand also was a important process in the activated sludge model. However there was noclear understanding of the endogenous respiration process at present. Although therewas literature analyzing endogenous respiration process, the variation characteristics ofmicrobial population at different stages during endogenous respiration were not listedout clearly.The main results were as follows:1.Based on this breathing maps method, the time that heterotrophic bacteria andautotrophic bacteria enter into the endogenous respiration could be effectivelydetermined. By analyzing respiration rate curve of heterotrophic bacteria andautotrophic bacteria in the breathing maps, the conclusions were that although the timeof two kinds of bacteria entering the endogenous microbial respiration were the same,their abilities to resist hunger were different. The time of heterotrophic bacteria andautotrophic bacteria entering into the endogenous respiration were different because ofdifferent components of the sludge.2. The quick recovery section of heterotrophic bacteria was higher than autotrophicbacteria. When hunger environment convert into a condition of sufficient matrix,heterotrophic bacteria microbial activity could obtain a high proportion of quickrecovery section, and their ability to resist shock loading was high, while autotrophicbacteria had opposite situation. Autotrophic bacteria were confirmed to be morevulnerable from the perspective of endogenous respiration. So in actual operation andmanagement of the sewage treatment plant, if lack of substrate for a long time, it wouldlead to huge loss of autotrophic bacteria or imbalance of sludge bacterial species,resulting in water quality of effluent could not meet the standard. 3. Indicators that use proportion of endogenous respiration to conduct quantitativedescription of health of active sludge were set, namely the increase of the proportion ofendogenous respiration rate could reflect the sludge activity may become worse. Theactivity of activated sludge changes caused the changes of respiratory rate, resulting inthe changes of endogenous respiration rate ratio. Using this method to analyze thechange of biomass in the sewage sludge during the operation of the plant was faster thanthe measurement method that use breathing measurement method to determine theconcentration of autotrophic bacteria and heterotrophic bacteria.4. The concentration ratios of autotrophic bacteria and heterotrophic bacteria wererelatively low in the activated sludge system which selected domestic sewage asinfluent, the situation was opposite in the activated sludge system which selectedartificial sewage containing easy degradation of matrix as influent.5. As the extension of SRT, the proportion of active bacteria decreased, as well asautotrophic bacteria and heterotrophic bacteria. If the sludge age was too short, theproportion of autotrophic bacteria may decline because of their loss, but theconcentration proportion of heterotrophic bacteria would not reduce. The conclusioncould provide theoretical foundation for efficient operation of sewage plant throughreasonably controlling the sludge age.