拉西环/陶粒双层填料BAF运行效果及反冲洗研究

Research on performance and backwashing of raschig rings/ceramic double-packed BAF

针对曝气生物滤池(biological aerated filter,BAF)反冲洗周期较短的问题,研究开发了拉西环/陶粒双层组合填料BAF工艺,并考察了其运行与反冲洗效果。结果表明,拉西环层对COD和SS具有明显的去除效果,去除率分别达到48%和52%;上部陶粒层0.6 m处可使NH+4-N浓度由23.8 mg/L下降至5.7 mg/L,硝化速率达到40.2 g NH+4-N/(h·m3);硝化菌比例随沿程逐渐增加,在0.4 m处已达95%左右。拉西环/陶粒双层填料BAF工艺运行良好,且可将系统反冲洗周期延长至16 d,反冲洗后可在较短时间恢复处理效果。

Aiming at the problem of short backwashing cycle of traditional biological aerated filter （BAF） , a double-packed BAF with raschig rings/ceramic as media was developed to investigate the operation performance and baekwashing characteristics. Results showed that the raschig ring layers could remove COD and SS efficient- ly, with the removal rate of 48% and 52% respectively. NH4＋-N concentration could be decreased from 23.8 mg/L to 5.7 mg/L in 0.6 m of the upper ceramic layer, with the rate of nitrification approaching as high as 40. 2 g NH4-N/（h · m3）. Meanwhile, the abundance of nitrifying bacteria increased gradually along the BAF height, which could reach about 95% at 0.4 m. Moreover, the running period could be extended to 16 days by the new process and the treatment performance could be recovered in short time after backwashing.