| In recent years,the use of reducing-type biological processor for on-site treatment of organic waste has been applied in many cities in our country.However,the problem of high-concentration tail water discharge during its operation has also attracted more and more attention.To a certain extent,its promotion and application are restricted.At present,there are few reports on the research on the high-efficiency purification treatment process of this kind of tail water.In this thesis,the tail water of the reducing-type organic waste biological processor is the object of treatment.Aiming at its high concentration of organic matter and suspended matter,the research was carried out by constructing an anaerobic-aerobic small-scale reactor device,and an efficient machine was developed.Mechanical Agitation Anaerobic Bioreactor（MAAB）-Moving Bed Membrane Bioreactor（MBMBR）treatment process,from the three aspects of treatment effect,stability and anaerobic sludge microbial community characteristics.The MAAB-MBMBR process was used to treat simulated tail water.Effectiveness and optimization of process parameters provided experimental basis and technical support for the actual engineering application of the process.The main findings of the thesis are as follows:（1）After the start-up of the MAAB pilot plant was completed,the efficiency of MAAB under 6 different operating conditions was compared by changing the simulated tail water concentration and influent flow rate.The average OLR in the first stage was9.84 g COD/（L·d）,and the average COD removal rate of MAAB was 81.4%.The average OLR in the second stage was increased to 11.04 g COD/（L·d）,and the average COD removal rate of MAAB was 81.6%.In the third stage,the average OLR increased to 12.00 g COD/（L·d）,and the average COD removal rate of MAAB was 84.0%.The average average OLR in the fourth stage increased to 14.55 g COD/（L·d）,and the average COD removal rate was 82.3%.The fifth stage OLR was 17.30 g COD/（L·d）,and the average COD removal rate reaches 83.4%.In the sixth stage,when OLR was increased to 21.73 g COD/（L·d）,the removal rate of COD by MAAB dropped sharply,and the removal rate of COD dropped rapidly to below 70%.After comprehensive analysed,the maximum OLR of the simulated tail water treatment efficiency of MAAB with a COD concentration of 20000 mg/L was 17.30 g COD/（L·d）.（2）The high-throughput sequencing method was used to investigate the microbial diversity and community structure changes of anaerobic sludge at different stages of MAAB operation.The microbial diversity and richness in sludge in MAAB first increased and then decreased with the increase of OLR.The dominant bacteria are Bacteroidota,Halobacterota,Synergistota and Spirochaetota.When the OLR was17.30 g COD/（L·d）,the relative abundance of Proteobacteria,Verrucomicrobiota and Actinobacteriota related to acid production increased.At the genus level,the relative abundance of Bifidobacterium and WCHB1-41 related to acid production increased.Among the archaea,Methanocorpusculum and Methanosaeta are the dominant genera.（3）In the process research of the aerobic section for the treatment of MAAB effluent,the treatment efficiency of the moving bed biofilm reactor（MBBR）was first investigated.When MBBR was treating the MAAB effluent,the aerobic sludge sedimentation tank sludge floating and losing,unable to operate stably.The effluent was difficult to meet the discharge requirements of the pipe.Then,an immersed ceramic flat membrane was added to the MBBR to construct a moving bed membrane bioreactor（MBMBR）to investigate the treatment efficiency of MBMBR on the MAAB effluent.The constructed MBMBR could operate efficiently and stably when treating the MAAB effluent at different stages.The average concentration of COD,NH3-N and TN of the effluent were 142 mg/L,9.07 mg/L and 36.5mg/L respectively,and the average removal rate reached 94.5%,90.4%and 75.0%,which meet the emission requirements of nanotubes.（4）The MAAB-MBMBR process developed in this paper can efficiently and stably treat the simulated tail water of the reducing-type biological processor for organic waste For tail water with a designed influent COD concentration of 20000mg/L,when the treatment efficiency was stable,the maximum OLR of the MAAB section was 17.30 g COD/（L·d）,the hydraulic retention time of the MBMBR section was 1d,and the total COD removal rate can reach 99.2%.NH3-N and TN was also effectively removed.The main pollutants of the effluent were not only far below the discharge limit of the pipe,but also can be used as flushing water for the reducing-type waste disposer. |
