Analysis Of The Application Conditions To Determine Reaction Rates Using Offline Respirometry

The meaning of offline respirometry method to determine the reaction rate is taking out some sludge from the reaction system in the state of offline, based on the respirometry method to measure the microbiological parameters of sludge, eventually determine the reaction rate of autotrophic bacteria and heterotrophic bacteria, the measuring method is simple and convenient, the period is short and there is no interference on the original system, it has a greater application value. This article mainly research the application conditions of using offline respirometry method to determine the reaction rate, aimed at making the practical application of offline respirometry method be possible, then provide a new idea about monitoring the reaction rate for water plant and help them to get the microbiological performance parameters of the system more accurately and faster.This paper respectively use traditional respirometry method, updated respirometry method, optimized respirometry method to measure the reaction rate offline, and at the same time complementary with RNH4-N chemical method, RNOX-N chemical method and jump point synthetic method. Then compare the measured value with the actual average reaction rate that measured by conduvtivity method, analysis the reasons of the differences and the application conditions of respirometry method. At the same time, this paper is based on the breathing atlas, studing the relationship between sedimentation performance and microbiological parameters, so as to evaluate the influence factors of microbiological reaction rate, extending and supplement the application conditions of offline respirometry method determine the reaction rate.The main research results are as fllows:1. When there are multiple paths exist in the process of pollutants removal, SBR offline respirometry method should be applied carefully on evaluating the reaction rate, especially for the reaction rate of autotrophic bacteria. In other words, the greater the nitrification speed, nitrification is the dominant role in a variety of degradation way, the exacter this method. Conversely, when nitrification is not dominant, while the other degradation process are the dominant roles, or the scene almost non-existent nitrification reaction, the deviation of reaction rate measured by offline respirometry method is bigger.2. The sludge sedimentation performance has a certain relevance with the biggest proliferation rate μmax, endogenous respiration rate, the actual amount of heterotrophic bacteria XH, heterotrophic bacteria proportion fH and nitrification rate OURN these five microbial parameters. The change of microbial parameters could affect the sludge floc structure, make the change of the sludge character, such as compactness, affecting the effect of mass transfer, and ultimately affect the reaction rate. Therefore, in the application of offline respirometry method determining the actual pollutant reaction rate, the change of microbiological characteristics of activated sludge should be paid attention to the impact on the reaction rate.