Technics Study On Biofiltration Of Odors From Oil Refining Wastewater Treatment Plant

The inorganized emission of odors from flotation tank of oil refining wastewater treatment plant in Daqing Petrochemical Company has endangered the ambience and the public health. The feasibility of biofiltration of odors and the effect factors were investigated in this work. The main technological parameters were also confirmed, which provided useful technological information for industrial application of this technology.In this study, the bofilters were packed with the mixture (i.e. packing media A) of compost, bark and lava, and the mixture (i.e. packing media B) of compost and polyethylene (PE), respectively. The effects of empty bed residence time (EBRT), air-flow mode, concentration of the contaminants, load shock and temperature on the removal odors were investigated. The variation of water content, pH value and nutrients of packing media in the biofilters was investigated. In addition, the effect of different packing media on the pressure drop of packing bed was also investigated. The following main conclusions were obtained:(1) The results showed that both of the compost-bark-lava (packing media A) and compost-PE (packing media B) could be used as the packing media of the biofilters. Packing media B was more suitable as packing media of biofilters to remove the odors from oil refining wastewater treatment plant.(2) The optimal EBRT was 66 s for treating odors in the biofilters packed with both packing media.In the biofilters packed with packing media A, at EBRT of 66 s, when the inlet concentrations of non-methane hydrocarbon (NMHC), benzene, toluene and xylene varied in the range of 5.1-1081.8, 0.1-328.8, 0.2-107.2 and 0.2-48.2 mg·m^-3, the corresponding average removal efficiency was 79.7 %, 98.9 %, 98.8 % and 99.6 %, respectively. When the maximum elimination capacity was 50.7, 17.6, 5.0, 2.6 g·m^-3·h^-1, the corresponding removal efficiency of 92.1 %, 99.0 %, 99.9 %, 99.3 %, respectively, was obtained.In the biofilters packed with packing media B, at EBRT of 66 s, with the inlet concentration of non-methane hydrocarbon (NMHC), benzene, toluene and xylene varying in the range of 5.1-1081.8, 0.1-328.8, 0.2-107.2 and 0.2-48.2 mg·m^-3, the average removal efficiency was 90.5 %, 99.2 %, 99.5 %, 99.9 %, respectively. The maximum elimination...