BAF单系统处理玉米青贮渗出液主要影响因素分析

Analysis of main influencing factors on corn silage effluent treatment by BAF system

采用单级曝气生物滤池系统处理玉米青贮渗出液,考察水力负荷、气水比、有机负荷和滤床高度对BAF系统运行的影响。研究结果表明：当水力负荷从0.5 m3/（m2.h）升高到3.0 m3/（m2.h）过程中,COD和NH3-N的去除率先升高后降低,当水力负荷为1.5 m3/（m2.h）时,COD和NH3-N的去除率达到最大,分别为83.5%和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的去除率达到最大,分别为87.5%和75.2%;低有机负荷不利于COD和NH3-N的去除,当有机负荷（以COD计）为2.4kg/（m3.d）时,COD和NH3-N去除率分别为49.6%和58.5%,但过高的有机负荷对NH3-N去除率影响较大,当有机负荷为7.2 kg/（m3.d）时,NH3-N去除率为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0.6~1.0 m区域,因此,适当增加滤床高度可以提高NH3-N去除率;采用BAF系统处理玉米青贮渗出液是可行的,为同类废水处理和控制农村水环境质量提供借鉴。

Single biological aerated filter was adopted to treat corn silage effluent from dairy farm of Fengyang, China. Four main influencing factors （hydraulic loading, gas-,vater ratio, organic loading and filter bed height） on BAF system were studied in this experiment. The results show that the removal rates of COD and NH3-N both increase at first and then decrease when hydraulic loading is from 0.5 m3/（m2.h） to 3.0 m3/（m2.h）, whose removal rates of COD and NH3-N reach the maximum with 83.5% and 74.9%, respectively at 1.5 m3/（m2.h）; with the increase of the gas-water ratio, the removal rates of COD and NH3-N increase when the gas-water ratio is up to 3.5：1, the removal rates of COD and NH3-N reach the highest, 87.5% and 75.2%, separately. COD and NH3-N are extremely difficult to treat under low organic loading, and when the organic loading is 2.4 kg/（m3-d）, the removal rates of COD and NH3-N only reach 49.6% and 58.5%, but the removal rate of NH3-N is also rather low under too high organic loading, when the organic loading is 7.2 kg/（m3.d）, the removal rate of NH3-N is just 61.7%. Influence of filter bed height upon treatment NH3-N is rather significant because of poor nitrification and the removal rate of NH3-N in the height range 0.6 m to 1.0 m is higher than others, therefore, the removal rate of NH3-N can be enhanced by properly increasing the filter bed height. It isfeasible and effective to treat corn silage effluent by BAF system, which offers useful references for wastewater treatment and rural water environmental quality control.