膜生物反应器中污泥的TCE硝化反应特性

Acclimation Behavior of Nitrifying Sludge Against Trichloroethylene by Membrane Bioreactor

采用一体式浸没膜生物反应器,在曝气、连续的条件下,间歇投加硝化反应的抑制物TCE(三氯乙烯),考察在不同TCE投加浓度下,TCE及其共代谢中间产物对硝化菌和异养菌活性的抑制情况,以及在TCE停止投加后,污泥相对硝化活性的变化趋势.虽然TCE对异养菌酶活性有一定的抑制作用,使CODMn的去除率呈下降趋势,但仍然没有被大幅度地降低;硝化菌由于对环境比较敏感,在TCE投加的初期,受抑制作用比较明显,氨氮的去除率呈下降趋势,但当硝化菌慢慢适应TCE共存环境后,其硝化活性将慢慢恢复,氨氮去除率将逐渐提高;停止投加TCE后,硝化菌仍然具有一定的耐TCE抑制的能力,且较高浓度TCE驯化的污泥的耐TCE抑制的能力也较高,但随着停止投加时间的延长,这种耐TCE抑制的能力将逐渐下降,直至消失.

The inhibition characteristic of TCE and its cometabolic intermediate on nitrifying and heterotrophic bacteria was investigated by a series of integrated and submerged Membrane Bioreactors. The results demonstrated that the COD removal efficiency was on the trends of declination after TCE addition, but not affected strongly during the period of adding TCE. Due to susceptible of sludge to the TCE inhibition at the beginning of TCE addition, the removal efficiency of ammonium was declined significantly. However, when the nitrifying bacteria became acclaimed to the TCE inhibition, its activities would be resumed gradually. In addition, after the stop of TCE addition, the nitrifying sludge could maintain its ability of antiinhibition of TCE for a long period, and the higher the concentration of TCE addition, the higher the ability of antiinhibition. But this ability would be declined gradually to disappearance in the absence of TCE addition.