天然沸石生物再生途径机理研究

在模拟沸石床系统中,对比探讨了曝气、异养菌和硝化细菌3个因素单独或共同作用对沸石再生效果的影响.结果表明,在本试验条件下,曝气作用、异养菌代谢和硝化作用分别可将沸石的再生效率提高0.5%~1.0%、20.9%~31.1%和120%~180%,3个因素影响大小依次为硝化细菌＞异养菌＞曝气吹脱.当异养菌与硝化细菌共存时具有协同再生作用,不仅可提高系统的再生效率(接近100%),而且还可提高沸石的再生率(约10%).离子交换、曝气和异养菌单独或共同作用下沸石的再生过程可用y =1-e-kx方程模拟;存在硝化细菌作用时沸石的再生过程前、后段分别用线性方程y =kx和Monod方程拟合(R2＞0.99).结合沸石再生前后表观形态变化的观测,探讨了沸石的再生机理.

The mechanism of bio-regeneration process of natural zeolite

Pilot-scale zeolite bed was constructed to discuss the influence upon the regeneration efficiency of zeolite by aeration, heterotrophic bacteria and nitrifying bacteria. The regeneration efficiency of zeolite was enhanced by 0.5%~1.0%, 20.9%~31.1% and 120%~180% with the present of aeration, heterotrophic bacteria and nitrifying bacteria, respectively. Nitrifying bacteria played a major role in the regeneration process of ammonia-saturated zeolite, followed by heterotrophic bacteria and aeration. When heterotrophic bacteria and nitrifying bacteria coexisted in a reactor, a synergistic effect had been observed, which could not only improve the regeneration efficiency up to 100%, but also increase the regeneration rate about 10%. The influence of ion-exchange, aeration and heterotrophic bacteria alone or in combination on the regeneration efficiency of zeolite fitted the first order kinetic reaction. And the curves of regeneration efficiency with nitrifying bacteria was described by y=kx and the Monod equation(R2＞0.99). Through investigation on the change of SEM on zeolite surface before and after zeolite biological regeneration, the mechanism of bio-regeneration process of ammonia-saturated zeolite was revealed.