曝气生物滤池对玉米青贮渗出液处理效果

Effect of biological aerated filter on corn silage effluent treatment

为了考察曝气生物滤池(biological aerated filter,BAF)处理玉米青贮渗出液的效果及其影响因素,重点考察了水力负荷、气水比、有机负荷和滤床高度。结果表明:水力负荷从0.5m3/(m2.h)升高到3.0m3/(m2.h)过程中,化学需氧量(COD)和NH3-N的去除率先升高后降低,当水力负荷1.5m3/(m2.h)时COD和NH3-N的去除率分别达到最大为83.5%、74.9%;增加气水比使得系统中溶解氧充足,可明显提高COD和NH3-N去除率,当气水比为3.5:1时COD和NH3-N的去除率分别达到最大为87.5%、75.2%;低有机负荷不利于COD和NH3-N的去除,当有机负荷为COD2.4kg/(m3.d)时,COD和NH3-N去除率最低分别仅为49.6%、58.5%,有机负荷为COD4.8kg/(m3.d)时去除率最高分别可达80.9%和75.9%,但过高的有机负荷反而对NH3-N去除不利,当有机负荷为COD7.2kg/(m3.d)时,NH3-N去除率降低为61.7%;滤床高度对硝化反应去除NH3-N影响较大,NH3-N生物硝化反应去除行为主要发生在0.6～1.0m区域。试验表明采用BAF系统处理玉米青贮渗出液是可行的,也为类似性质废水处理和改善农村水环境质量提供有益的参考。

To investigated the effect of biological aerated filter on corn silage effluent, four main influencing factors （hydraulic loading, gas-water, organic loading and filter bed height） on BAF system were studied in this experiment. The results showed that the removal rate of COD and NH3-N were increased at first and then decreased under 0.5 m3/（m2·h） to 3.0 m3/（m2·h） of hydraulic loading; with 1.5 m3/（m2·h） of hydraulic loading, the maximum of the removal rate of COD and NH3-N obtained were 83.5%, 74.9%, respectively. The removal rate of COD and NH3-N were increased with the increasing of the gas-water ratio at the gas-water ratio of 3.5：1; the removal rate of COD and NH3-N reached the highest, at 87.5% and 75.2%, respectively. The removal rate of COD and NH3-N was 49.6% and 58.5% with 2.4 kg/（m3.d） of the organic loading COD, respectively, reached the maximum（80.9% and 75.9%, respectively） with 4.8 kg/（m3-d） of the organic loading COD, and was low with 7.2 kg/（m3.d） high organic loading, about 61.7%. The influences of filter bed height upon NH3-N removal were extremely significant, the removal rate of NH3-N at the height range 0.6 to 1.0 m was higher than the others. Therefore, it is feasible and effective to treat corn silage effluent by BAF system. The results provide useful references for wastewater treatment and rural water environmental quality control.