Pilot Research On The Treatment Of Oil Refinery Wasterwater By The Process Of A/O+MBBR

At present, the reports of combination process of MBBR method and activated sludge (A/O) which is using to deal with wastewater is less. How to achieve the two processes complement each other is a study subject in the field of sewage treatment. To supply the parameters of combined process for the production applications author carries out a pilot test at Anqing Petrochemical using A/O+MBBR method. In this paper, two different processes are used to treat the oil refinery wastewater.,the removel rate of COD& NH₄⁺-N and the capability of resistance to organic shock loads are studied. The results of this research are as follows:1,In the process of A/MBBR3 the removal efficiency of COD and NH₄⁺-N are 92.4% and 99.8% on the condition of water intake amount 0.6-0.9m³/h, dissolved oxygen(DO) 2-4mg/L, average hydraulic retention times(HRT)14.3h. The results are so good that reach to the first level of discharge standard of "Discharge Standard of Pollutants for Municipal Wasterwater Treatment Plant"(GB8978-1996).2,Study the removal efficiency of COD and NH₄⁺-N on the condition of the HRT is 11.7h,13.1h,15.0h and l7.5h in the process of A/MBBR³. Considering the volume loading, the removal efficiency and cost-effective, in actual operation, it would be preferable to control the HRT 13h.3,In the process of A/O²/MBBR the removal efficiency of COD and NH₄⁺-N are 83.2% and 99.5% on the condition of water intake amount 0.2-0.3m³/h, dissolved oxygen(DO) 2-4mg/L, average hydraulic retention time(HRT)48h. The outwater quality is good.4,Considering the circulation flow rate and economic factors, in this experiment the fill rate is 30%-50%, which is feasible through the effect of treatment verification.5,Faults and changes in influent water quality effects for treatment device are analyzed in this experiment. The results show that the combined process of A/O+ MBBR treatment function can restore after attack in 48h.The system has a strong impact load capacity. 6,The MBBR combined process has certain advantages in sludge reduction. Reduction effect could reach 20%-40%,reducing the sludge treatment and disposal burden.The conclusion of this experimental studies shows that the combination process of MBBR and activated sludge has the characteristic of high efficiency,stable water quantity and strong resistance to organic shock loads.From the results we can say using MBBR to improve current oil refinery wasterwater plant is absolutly feasible.We can ensure water quality on the condition of not change the constructure of aeration tank.