The Transformation Of Biological Aerated Filter And Treatment Of Refinery Wastewater By Coupling Efficient Multi-Stage Biological Treatment And Fenton Fluidized Bed

China is a country with serious water pollution, oil refining wastewater as difficult treatment of industrial wastewater, whether it’s discharging standard profoundly affects the surface water environment. For the petrochemical enterprises, mainly through the reform of the existing sewage treatment facilities or the new sewage treatment plant using new technology to achieve discharge standard. The research work of this thesis is mainly divided into two parts:one was transform aeration biological filter of a petrochemical enterprise, replacement of packing and adding the efficient microbial strains, in order to achieve the purpose to improve the quality of the water; the other was analysis the refinery sewage after pre-treatment, using coupling efficient multi-stage biological treatment and Fenton fluidized bed to treatment the wastewater, provide the basis for the reconstruction of the factory. Through the experiment, results are as follows:1. Biological Aerated Filter (BAF) has been used for advanced treatment of petrochemical wastewater in a petrochemical enterprise. But, it is gradually difficult for the effluent water quality to meet the emission standards, because of the inherent disadvantages and ageing of the BAF’s lava carrier. To solve this problem, porously suspending carrier was used to displace the traditional lava carrier. After reformation of the BAF, the average COD removal rate is about 28.1%, which is higher as 1.19 times as that before reformation, the average ammonia nitrogen removal rate was improved from 23.2% to 25.8%. The COD and ammonia values could reach the A standard of Discharge Standard of Water Pollutants for Municipal Wastewater Treatment Plants (DB11/890-2012).2. The refinery wastewater of some petrochemical enterprises was treated by combining efficient multi-stage biological treatment and Fenton fluidized bed. The effects of hydraulic retention time on the treatment effectiveness of multi-stage biological treatment system and pH, H2O2/Fe2+ Moore ratio, H2O2/COD mass ratio on the treatment effectiveness of Fenton fluidized bed reactor have been investigated. The results show that the optimal hydraulic retention time was 43.2 hours for multi-stage biological treatment system; the optimal cost-effective condition by Fenton fluidized bed was obtained:pH of 3-4, the dosage of H2O2 and FeSO4·7H2O were 1.0 g·L-1 and 2.0 g·L-1, the reaction time was 30 minutes. Combined process under 45 h of total hydraulic retention time, when the range of influent COD concentration was changes in the larger range of 435～1020 mg·L-1, the average effluent COD concentration was lower than 30 mg·L-1, and the average removal rate reaches 96.54%. When the range of influent ammonia nitrogen concentration was changes in 9.36～31.2 mg-L-1, the value of ammonia nitrogen value was decreased to 0.05 mg·L-1, and the average removal rate is about 99.72%. The quality of the treated water reaches the first criteria specified in Integrated Wastewater Discharge Standard (GB 8978-1996).