Experimental Study About Efficiency Of AOA-MBR System On Ship Domestic Sewage Treatment

With the rapid development of shipping industry,a large number of domestic sewage has been discharged into the sea without efficient treatment,which has caused serious damage to the marine ecological environment.Due to the large volume of water and the high degree of pollution and the increasingly stringent requirements of the International Maritime Organization,the development of efficient,stable and practical ship sewage treatment technology is currently one of the research focuses in the field of ship domestic sewage control.This paper uses an external alternating operation of the MBR anaerobic / aerobic / anoxic ultrafiltration(AOA-MBR)removal of new ship sewage processing to investigate the anti synchronization of nitrification,treatment efficiency and optimize the operation conditions,the biological technology and simulation technology on pollutant removal mechanism analysis.In the fast start-up stage of reactor,after 21 d inoculation,the reactor has high removal rate of COD,TN and TP,and runs stably.The strain analysis showed that denitrifying phosphorus accumulating bacteria accounted for 45.5% of total phosphorus accumulating bacteria.It is suggested that the operation mode of A/O/A is helpful to the rapid enrichment of denitrifying phosphorus accumulating bacteria and the system start.In order to optimize the operation cycle,we can monitor the biological reaction process in different stages by monitoring environmental indicators such as pH,DO and ORP value.The best cycle is: anaerobic 2.0h,aerobic 3.5h,anoxia 1.5h,meanwhile,it provides operability for online regulation and treatment efficiency.Effect of influent load on the treatment efficiency was investigated by changing the influent concentration of COD,C/N and the ratio of C/P to explore the efficiency of nitrogen and phosphorus removal reactor system.The results show that when the concentration of COD is 700mg/L and C/N/P=35:3.2:1,the reactor nitrogen removal rate of 96.8%,the removal rate reached 92.3%,the amount of phosphorus sludge suction up to 16.57mgTP/gMLSS,denitrifying phosphorus removal sludge phosphorus absorption amount far exceeds the traditional biological phosphorus removal technology,show that the AOA-MBR process is suitable for treatment of high nitrogen and phosphorus content of ship sewage.At the same time,the experimental results also showed that the excess carbon source and TN had adverse effects on the removal of TP during the reaction.The denitrifying phosphorus removal sludge and sludge were analyzed by using early inoculation high-throughput macro gene sequencing technology,it was found that the initial denitrifying phosphorus removal sludge and sludge are obviously different,not only the community structure changed significantly,and more abundant species,nitrifying bacteria,spirochetes and Proteobacteria showed a substantial increase in the number,A/O/A operation in the aspect of biological denitrifying phosphorus removal system has great advantages compared with the traditional process.The AOA-MBR synchronous denitrifying phosphorus removal system was modeled by Biowin software.After calibrating the parameters,the simulation results were good.The average relative errors of simulated values and measured values for COD,TN and TP were 5.61%,2.14% and 4.22%.