Study On The Treatment Of Kitchen Waste Water By External Anaerobic Membrane Bioreactor

With the development of society,the amount of kitchen waste is getting larger and larger,and the amount of kitchen waste water generated after biochemical treatment is also very large.This type of wastewater still contains high organic pollutants and should not be directly discharged.In this study,the kitchen waste water wastewater was used as the research object.The effects of different organic loads(OLR)on the performance of the reactor were studied under an intermediate temperature condition using an external anaerobic membrane bioreactor(Anaerobic Membrane Bioreactor,AnMBR).The high-throughput sequencing analysis of the sludge in the lower reactor and the membrane surface was carried out,and the microbial community composition changes in the AnMBR and membrane surface were preliminarily investigated.This study smoothly entered the processing and operation process through the completion of the rejuvenation and domestication process.The whole experiment mainly achieved the following results:1.The operation process is continuous under the condition of OLR of 10.00,15.00,20.00 gCOD/(L·d),and AnMBR is basically in a stable state.The test results show that when the OLR is 15.00 gCOD/(L-d),the removal effect of each substance,the gas production effect and the stability of the system operation are in an optimal state.The pH value fluctuates around 7.00,the VFA concentration is stable below 480 mg/L,the ALK fluctuates around 3000 mg/L,and the VFA/ALK ratio is basically stable below 0.2.The acetic acid content in VFA is dominant;and the maximum specific gravity is 97.2%,the removal rate of COD,carbohydrate and protein in effluent reached 90%,98%,80%,and the maximum daily gas production was 177.03 L/d.2.The microbial community composition has also changed significantly with changes in operational load.When the OLR is 15.00 gCOD/(L·d),high-throughput sequencing results indicate that at the gate level,the main dominant bacteria are Bacteroidetes,Spirochaetae,and Euryarchaeota.At the genus level,the main dominant bacteria are Sphaerochaeta,Bacteroides,Methanobacterium,and Methanocorpusculu,m.The relative abundance of bacteria in the reactor is high,the diversity is high,and the relative abundance ratio of archaea is low.When OLR was 20.00 gCOD/(L-d),the surface of the genus Sphaerochaeta accounted for 40.23%,and the content of archaea was 4.42%.It was found that serious membrane fouling was closely related to the increase of microbial abundance on the membrane surface.