不同填料组合的曝气生物滤池前置反硝化工艺特性的比较研究

研究了2组不同填料组合的前置反硝化曝气生物滤池(BAF)脱氮工艺:陶粒-沸石工艺(C-Z BAF)和沸石-陶粒工艺(Z-C BAF),比较二者在不同的水力停留时间(HRT)、气水比和回流比条件下的工艺特性。当进水COD、氨氮和TN容积负荷分别为0.72～5.97、0.09～0.60和0.11～0.78 kg/(m3.d)时,C-Z BAF和Z-C BAF的最佳HRT、气水比和回流比分别为1.5 h、5∶1、1∶1和1.5 h、5∶1、2∶1,相应COD、氨氮和TN的平均去除率分别为94.7%、99.0%、62.2%和93.2%、99.5%、70.1%。单因素方差分析结果表明,HRT对2组工艺的各种污染物的去除率均有显著影响;回流比对Z-C BAF的TN去除率存在显著的影响,而对C-Z BAF的TN去除率几乎没有影响。污染物沿程分布分析结果表明,两组工艺的COD去除主要发生在缺氧滤池以及好氧滤池0～0.3 m的填料区;硝化作用主要发生在好氧滤池的0～0.6 m填料区,Z-C BAF工艺的硝化速率高于C-Z BAF工艺。Z-C BAF工艺存在明显的同步硝化反硝化作用,且Z-C BAF工艺的脱氮性能优于C-Z BAF工艺。

Comparitive study on two biological aerated filter processes with different media combination for pre-denitrification/nitrification of grey water

The performance and characteristics of two separated pre-denitrification processes using biological aerated filter(BAF),ceramic-zeolite BAF(C-Z BAF),and zeolite-ceramic BAF(Z-C BAF),were investigated and compared under various HRTs,reflux ratios and air-liquid ratios for treating grey water.The optimized HRT,air-liquid ratio and reflux ratio of C-Z BAF and Z-C BAF were 1.5 h,5∶ 1,1∶ 1 and 1.5 h,5∶ 1,2∶ 1,respectively,while influent volumetric loading rates for COD,NH3-N and TN were 0.72~5.97,0.09~0.60,and 0.11~0.78 kg/m3·d.Under the optimal conditions,the mean removal efficiency of COD,NH3-N,and TN were 94.7%,99.0% and 62.2%,respectively for the C-Z BAF;and 93.2%,99.5%,and 70.1%,separately for the Z-C BAF.The results of one-way ANOVA showed that HRT had significant effect on the removal of COD,NH3-N and TN of both processes;reflux ratio had significant effect on the TN removal of Z-C BAF while had no significant effect on that of C-Z BAF.The profile of pollutants along the flow path in the two BAF systems indicated that the COD was oxidized in the anoxic filter and the media of 0~0.3 m in oxic filter;the nitrification mainly happened in the media of 0~0.6 m in oxic filter and the Z-C BAF had higher nitrification rate than C-Z BAF;Z-C BAF had remarkable simultaneous nitrification and de-nitrification phenomenon,thus the de-nitrification efficiency of Z-C BAF was better than that of C-Z BAF.