不同曝气强度下SBMBBR和SBR脱氮除磷性能对比研究

对比考察了不同曝气强度下序批式活性污泥反应器(SBR)和序批式移动床生物膜反应器(SBMBBR)的脱氮除磷效果,并分析了反应器单个周期内有机物、氮和磷的转化过程.实验结果表明,SBMBBR和SBR脱氮主要是基于好氧段发生的同步硝化反硝化(SND)及进水、搅拌阶段发生的缺氧反硝化途径实现的,而除磷是基于常规生物除磷和反硝化除磷过程而完成.曝气强度会影响SBR和SBMBBR好氧阶段SND发生的程度,最佳曝气强度下两者通过SND作用去除的TN量分别达到去除总量的47.7%和79.0%.在采用先行厌氧的运行方式,保持系统内高浓度微生物,使反应器在进水C/N比只有2.2～3.5的条件下均取得了良好的脱氮除磷效果.两者相比,SBMBBR和SBR在COD和NH4-N去+除方面没有差异,而SBMBBR的反硝化、除磷效果更优,TN、TP去除率分别达到95.4%和93.5%,较SBR分别高出10.9%和4.1%.

Characteristics of nitrogen and phosphorus removal in SBR and SBMBBR with different aeration rates

Nitrogen and phosphorus removal were investigated in sequencing batch activated sludge reactor (SBR) and sequencing batch moving bed biofilm reactor (SBMBBR) under different aeration rates. COD, nitrogen and phosphorus profiles in a single operating circle were analyzed. The experimental results indicated that, in both SBMBBR and SBR, nitrogen removal was mainly accomplished by simultaneous nitrification and denitrication (SND) process at aerobic phase and anoxic denitrification process at filling and mixing phase. Phosphorus removal was realized through conventional phosphorus removal and denitrifying phosphorus removal processes. Aeration rate affected the occurrence of SND, and under the optimum aeration rate nitrogen removal during SND process accounted for 47.7% and 79.0% of the total nitrogen removed in SBR and SBMBBR, respectively. Ideal nitrogen and phosphorus removal efficiencies were achieved when operated first in anaerobic mode and kept high concentration of microorganism with influent C/N ratio of 2.2~3.5. While COD and NH⁺₄-N removal efficiencies were similar in both type of reactors, better denitrification and phosphorus removal effect were achieved with TN and TP removal efficiencies of 95.4% and 93.5% respectively, in SBMBBR, which was 10.9% and 4.1% higher than that of SBR.