Study On Facultative And Anaerobic Biochemical Process Of Wastewater By Microreactor

Anaerobic biodegradability is an evaluation of the ability of anaerobic microorganisms to metabolize organic matter under anaerobic conditions.The measurement of microbial gas production and the measurement of gas composition are very important to evaluate the anaerobic biodegradability.At present,the determination of anaerobic biodegradability of wastewater is mainly carried out by gas collection method,but the method is difficult and the accuracy of the result is low.In order to overcome the above shortcomings,this paper uses anaerobic bio-tank to simulate the actual anaerobic process,uses the reaction bottle of the tile type absorber as the bio-chemical micro-reactor,and uses the manometer tube as the metering device for gas production,the gas yield of wastewater during anoxic and anaerobic biochemical process was measured and the biochemical curve was drawn.The biochemical curve was analyzed and different anaerobic biochemical characteristic models were induced.The results are as follows:1、It takes a certain time for the system environment of a newly-started anaerobic biochemical device to change into a complete anaerobic state,and other factors such as the type of wastewater and the type of bacteria in the system environment are all related to the start-up time,the time required for its transformation is defined as the start-up period of an anaerobic biochemical system,and the size of T_OAreflects how easy it is for a newly-started biochemical system to completely transform into an anaerobic biochemical state.2、Through a large number of biochemical contrast experiments,it is found that the anaerobic biosorption curve of microorganisms can be divided into two models,Therefore,two hypothetical models of anoxic biochemical unit are proposed."trapezoidal"model A and"checkmark"model B;Which essentially mean the biochemical characteristics of different wastewater.When the curve is like"check",it is called"model B",the molecular weight of the model wastewater is relatively small,the macromolecular substances decompose quickly in the anaerobic stage,and the short-term facultative oxygen has been completed In the end of the hydrolysis stage,aerobic bacteria began to decompose strictly;3、The bacteria in anaerobic process absorb similar rules,through simulating ten kinds of anaerobic process under different waste water and system environment,using tile as gas-producing instrument,the results showed that the bacteria in the wastewater sample of micro-reactor had high respiratory intensity in 1h,and the anaerobic reaction was slow after 1h.Therefore,the anaerobic Biochemical Index K_Ais defined by the anaerobic gas yield at 1h.K_Awas used to characterize the rate of organic macromolecule consumption and the rate of anaerobic bacteria producing CH₄in wastewater.4、The COD volumetric load is related to the gas production of anaerobic bacteria.Through the analysis of the relationship between the COD volumetric load and the anaerobic biochemical index K_Aof ten different wastewater,it is found that the smaller the K_Aindex is,the larger the COD volumetric load is,when K_A≤-80,the COD volume load of the anaerobic biochemical unit was more than 3kg/（m³·d）,the anaerobic biodegradability of the wastewater was good;and when K_A>-80,the COD volume load of the anaerobic biochemical unit was less than 3kg/（m³·d）.When the K_Aindex is detected,the COD volume load of wastewater can be estimated roughly,then the method can be used to predict the COD volume load of anaerobic biochemical units.5、The anaerobic biochemical characteristic model proposed in this question combines the multi-factors of wastewater anaerobic biochemical system（such as p H、T、SS）,and has high practical application value for the design of general anaerobic wastewater biochemical treatment engineering.