曝气生物滤池深度处理石化废水的试验研究

Experimental Study on BAF for Advanced Treatment of Petrochemical Wastewater

采用接种挂膜法,以中试规模的曝气生物滤池(BAF)深度处理某石化企业经纯氧曝气处理后的二级出水,考察了正常负荷和冲击负荷下的处理效果,确定了反冲洗参数。结果表明,正常负荷下采用低滤速运行时,BAF对COD和浊度的平均去除率分别为34.1%和84%;采用高滤速运行时BAF对COD和浊度的平均去除率分别为35.3%和86.6%。BAF具有较强的耐冲击负荷能力,在进水COD平均为78.9 mg/L、浊度平均为3.64 NTU的条件下,对COD和浊度的平均去除率分别为55.4%和81.9%。采用先气冲后水冲的方式对BAF进行反冲洗,气冲时间为2 min,强度为25 m3/(h.m2),水冲时间为8 min,强度为12.5 m3/(h.m2),反冲洗周期为1个月,反冲洗后生物膜中微生物的活性可较快恢复。

Biological aerated filter （BAF） technology was used for treatment of secondary effluent from pure oxygen aeration system in a petrochemical plant. In the pilot-scale experiment, the inoculating method was used to develop biofilm on the media, the treatment effect under normal and shock loading was investigated and the backwashing parameters were determined. The results show that under the condition of normal loading, the average removal rates of COD and turbidity are 34.1% and 84% respectively at lower filtration rate, and 35.3% and 86.6% at higher filtration rate. The results of impact experiment also show that the shock loading of PTA wastewater can be resisted effectively by BAF process. The average removal rates of COD and turbidity are 55.4% and 81.9% respectively when the average influent COD and turbidity are 78.9 mg/L and 3.64 NTU. The backwashing method is air washing followed by water washing. The time and intensity of air washing are 2 min and 25 m^3/（ h · m^2 ） respectively. And these of water washing are 8 min and 12.5 m^3/（ h · m^2 ） respectively. The cycle of backwashing is 1 month for this water quality. Activity of microorganism in biofilm may recover soon after backwashing.