反粒度生物滤池初滤水浊度控制研究

Turbidity Control in Initial Effluent of Reverse Grain Biological Filter

在反粒度生物滤池/臭氧-生物活性炭组合工艺处理微污染水源水过程中,存在反粒度生物滤池初滤水浊度过高,进而影响后续臭氧-生物活性炭工艺稳定运行的情况,针对这一问题进行了反粒度生物滤池初滤水浊度控制研究。以反粒度生物滤池出水浊度<1.5 NTU为预设目标,通过直接排放初滤水、延时启动、延时与慢速启动联用、降低运行初期滤速、二次絮凝、延时启动后二次絮凝与慢速启动联用等6种技术措施对反粒度生物滤池出水浊度进行了控制研究。结果表明,直接排放初滤水至出水浊度<1.5 NTU需要40 min,初滤水排放量约占每一个运行周期处理水量的1.4%,浪费了大量水资源;另外5种措施对浊度控制有一定效果,其中,延时10 min后缓慢启动并进行二次絮凝(絮凝剂投加量为7 mg/L,投加时间为30 min)工况下,初滤水浊度峰值<10NTU,10 min内初滤水浊度可降至1.5 NTU,控制效果较为理想。

Several operational techniques were tested to reduce the turbidity to below 1.5 NTU in the initial effluent in a reverse grain biological filter, in order to protect the subsequent ozone/biological activated carbon process in the treatment of micro-polluted water. The operations included discharging in- itial effluent directly, delaying start-up, slow start-up after delaying, reducing the initial operational fil- tration velocity, secondary flocculation, and secondary flocculation combined with a slow start-up after delaying. The results showed that discharging initial effluent directly could reduce initial filtered water turbidity to below 1.5 NTU within 40 min ; however, approximately 1.4% of treated water was discharged in each cycle. The other five techniques could control turbidity effectively to a certain degree as well. Es- pecially, through the operation of secondary flocculation （7 mg/L PAC, 30 rain） with a slow start-up af- ter 10 min of delaying, the turbidity was reduced to below 1.5 NTU within 10 min and the highest turbid- ity was below 10 NTU.