有机负荷对膜-生物反应器硝化性能的影响

采用厌氧动态膜-生物反应器(AnDMBR)组合自养膜-生物反应器(MBR)工艺,研究冬季低温条件下系统的硝化效果以及TP的去除效果,并与单级MBR工艺进行对比。结果表明:(1)AnDMBR对COD的去除率基本保持在50%～60%,AnDMBR组合自养MBR工艺对COD的去除率为80%～85%;单级MBR工艺对COD的去除率为80%左右。(2)总体上,AnDMBR组合自养MBR工艺对NH4+-N的去除率大于95%;单级MBR对NH4+-N的去除效果比AnDMBR组合自养MBR工艺差。(3)AnDMBR组合自养MBR工艺中,出水NO2--N与NO3--N均有积累;单级MBR工艺中,出水NO2--N积累不明显。(4)相对于亚硝酸盐氧化菌(NOB),氨氧化菌(AOB)对有机负荷更敏感,当有机负荷高时,AOB更易受到异养菌活动的抑制;当有机负荷降低、异养菌活性减弱时,AOB活性明显增强,系统的硝化效果得到明显改善。(5)AnDMBR组合自养MBR工艺对TP的去除率高于80%,单级MBR工艺稳定后对TP的去除率仅为20%～30%。(6)从呼吸速率和硝化速率可知,自养MBR的硝化效果优于单级MBR。

Influence of organic loading on nitrification characteristics in membrane bioreactor

Anaerobic dynamic membrane bioreactor(AnDMBR) coupled with autotrophic membrane bioreactor(MBR) was employed to investigate the influence of organic loading on nitrification characteristics and removal efficiency of total phosphorus(TP) in low temperature condition.A comparison between this combined process and a single-MBR process was carried out.Results indicated that AnDMBR led to a 50%-60% of COD removal efficiency and combined process led to a 80%-85% of COD removal efficiency,while the performance of single-MBR process for COD removal was about 80%.In combined process,the removal efficiency of NH+4-N was over 95%,and single-MBR process had a lower removal efficiency than combined process.Both of nitrate nitrogen(NO-3-N) and nitrite nitrogen(NO-2-N) had been accumulated in effluent of combined process,while effluent of single-MBR process had no obvious accumulation of NO-2-N.Ammonium oxidation bacteria(AOB) was more easily influenced by organic loading than nitrite oxidation bacteria(NOB),which meant high organic loading inhibited activity of AOB.When organic loading decreased,the proportion of nitrification autotrophic bacteria was increased,and the nitrification efficiency of combined process was improved.Combined process led to a >80% TP removal efficiency,while single-MBR process led to a 20%-30% TP removal efficiency.The value of respiration rate and nitrification rate showed that autotrophic MBR had higher nitrification efficiency than single-MBR process.