The Optimization Plan About Rapid Conditions Of Aerobic Granular Sludge And The Study Of Treatment Efficiency

In recent years,compared with the traditional activated sludge,aerobic granular sludge as a rising star of water treatment technology has become a research hotspot of many researchers.Aerobic granular sludge has the advantages of high efficiency and low cost,which is expected to be put into large-scale use in wastewater treatment.However,there are still many problems to be solved before it is put into operation,such as slow start-up of aerobic granular sludge,and unstable operation.According to the start-up conditions of aerobic granular sludge system,two optimization experiments were carried out to treat domestic sewage with the optimized aerobic granular sludge.In order to provide data and theoretical support for the optimization of aerobic granular sludge conditions,the microbial community structure of aerobic granular sludge was analyzed.Firstly,three different carbon sources(sodium acetate,sucrose and glucose)were used to start the aerobic granular sludge system in the sequencing batch reactor(SBR)under the conditions of high organic load,high ammonia nitrogen load and high aeration.Sludge morphology,sludge concentration,sludge volume index,extracellular polymer(EPS)content and conventional water quality index were mainly detected.From the start-up time and operation stability of the system itself and the influence of the above three optimization conditions on the start-up effect of aerobic granular sludge system,it is concluded that the system is the most stable when sodium acetate is the carbon source,with the highest COD removal rate of94.76% and the total nitrogen removal rate of 81.64%.Based on the results,the second optimization start-up experiment was carried out.Three different concentrations(50mg / L,75 mg / L,100 mg / L)of magnetic iron nanoparticles were used to study the effect of magnetic iron oxide nanoparticles on the start-up optimization of aerobic granular sludge system.The reactor was operated under the optimal conditions obtained for the first time,and the water quality index was measured to reflect the treatment capacity of aerobic granular sludge for wastewater.Observe the growth of sludge every day to judge whether the system is started successfully.According to the experimental results,75 mg / L ferromagneticnanoparticles had the best effect on the synthesis of EPS from aerobic granular sludge,and the sludge concentration was as high as 7045.61mg/l under this condition.From the results of domestic sewage treatment,it is found that the removal efficiency of COD and total nitrogen by aerobic granular sludge with 100 mg / L ferromagnetic nano addition is not ideal.After high pass sequencing of the two optimized aerobic granular sludge,it was found that the diversity of alpha in the sludge decreased with the gradual stability of the system.In the aerobic granular sludge obtained under each optimization condition,the dominant bacteria include bacteria with nitrification or denitrification ability.