污水深度处理过滤罐反冲洗工艺的优化

Process Optimization of Filter Tank Backwashing for Wastewater Advanced Treatment

针对油田污水深度处理设备运行一段时间后出现的过滤罐过流量下降、反冲洗后短时间内污水含油量偏高等现象,对过滤罐的反冲洗工艺进行了调整,考察了反冲洗压力、反冲洗周期、反冲洗程序对过滤罐过滤效果的影响。试验结果表明:最佳反冲洗压力为250 k Pa,在此条件下滤料的更换周期长达半年之久,过流量约为310 m3/h;最佳反冲洗周期为35 min;调整后的反冲洗程序为在每次反冲洗前先不提起盖板,使滤料在压缩状态下水冲洗5 min,水冲洗完成后再开始正常的气、水反冲洗过程。调整反冲洗程序后过滤罐出口污水含油量下降了6 mg/L,平均值为8 mg/L。

Aiming at the device problems in advanced treatment of oilfield wastewater, such as the excess flow decrease of filter tank in operation and the higher oil content of the effluent after backwashing for a short time, the backwashing process of filter tank was adjusted and the effects of backwashing pressure, backwashing cycle and backwashing procedure on filtration were investigated. The test results indicate that： The optimum backwashing pressure is 250 kPa, under which the replacement cycle of filter materials is up to half a year and the excess flow is about 310 m^3/h; The optimum backwashing period is 35 min. The backwashing process is adjusted as follows： Before each time of backwashing, the compressed filter materials are water-washed for 5 min with the cover closed, after that the normal gas-water backwashing process can be started. After the adjustment, the oil content of the filter tank effluent is decreased by 6 mg/L and the average value is 8 mg/L.