影响MBR脱氮效率的因素研究

Nitrogen removal in A/O and SND processes using MBR

采用重力出流式膜生物反应器,考察了采用2种脱氮运行方式对生活污水脱氮的效果,同时对影响脱氮效率的相关因素进行了分析.研究结果表明,C/N是影响A/O与同步硝化反硝化(SND)2种运行方式脱氮效率最关键的因素.当C/N比小于12时,A/O方式的脱氮效率高于SND;随着C/N的升高,A/O与SND脱氮效率的差距逐渐缩小.对于A/O运行方式,在低C/N条件下可以通过提高回流比与增加缺氧段的HRT来提高系统的总氮去除率.而对于SND运行方式,好氧反硝化的完成是建立在有足够有机物作碳源的基础上,此时,DO的控制就成为提高脱氮效率的关键因素.

A labor-scale experiment was carried out to compare nitrogen removal by a submerged membrane bioreactor （MBR） in the A/O and SND processes. The results indicated that nitrogen removal was controlled mainly by the value of C/N of the influent. Nitrogen Removal in the A/O was better than in the SND at the same ratio of C/N. However, the role of C/N on denitrification was relatively significant in the SND process. The impact of MLSS internal recycling ratio and HRTanoxic on denitrLfication was observed only at some C/N levels in the A/O process. As C/N was at high level, denitrification became increasingly dependent on DO at SND process.