用循环曝气生物滤池工艺处理炼油碱渣废水

Treatment of spent caustic wastewater from petroleum refinery using circulating biological aerated filter process

采用新型的两级循环曝气生物滤池工艺,对稀释中和后的炼油碱渣废水进行生物处理工业试验。研究了溶解氧质量浓度、水力停留时间、营养物质、pH值、温度和反冲洗周期等因素对碱渣废水生物处理效果的影响。在适宜的操作条件下,炼油碱渣废水经两级生物处理后,COD、硫化物、挥发酚和石油类平均去除率分别达到89.3%、99.8%、93.6%和85.7%,其中COD和硫化物的平均去除负荷分别达到8.37 kg.m-3.d-1和4.44 kg.m-3.d-1。循环曝气生物滤池是一种高负荷、高效率、反冲洗周期长和低成本的炼油碱渣废水处理方法,具有良好的应用前景。

The spent caustic wastewater from petroleum refinery contains high concentration sulfide, phenol and oil pollutants. A novel two stage circulating biological aerated filter （CBAF） was used to treat the wastewater after dilution by water and neutralization by H2SO4. The factors of dissolved oxygen （DO） concentration, hydraulic retention time （HRT）, nutrient, pH value, temperature and backwashing cycle, which affected the treatment efficiency of spent caustic wastewater were investigated. The experimental results showed that the average removal percentages of COD, sulfide, volatile phenol and oil pollutants were 89.3%, 99.8%, 93.6% and 85.7%, respectively under feasible conditions. The average removal loading rates of COD and sulfide pollutants were 8.37 kg · m^-3 · d^-1 and 4.44 kg · m^-3 · d^-1, respectively. The experimental results also showed that the CBAF process was a kind of high loading rate, high treatment efficiency, long backwashing cycle and low cost treatment process with a good application prospect for the treatment of spent caustic wastewater from petroleum refinery.