火山岩填料曝气生物滤池内循环强化脱氮试验研究

Experimental study on enhancing nitrogen removal by effluent recirculation in a BAF reactor with crushed lava packed as carriers

试验表明,被粉碎的火山岩是一种较好的曝气生物滤池填料。出水内循环虽然对COD、SS以及浊度没有太大影响,甚至因试验期间低温限制使得硝化效果改善并不明显,但内循环可以显著提高曝气生物滤池反硝化(脱氮)效果。在内循环比为150%时,硝化过程中产生的NO3-几乎均能被反硝化完全去除,只是由于试验时的低温限制了硝化效率使TN去除效率提高幅度受到限制,从无内循环时的43.8%仅仅被提高到69.1%。DO值沿填料层高度呈山谷型分布(谷底位于填料层50 cm处)规律揭示,DO谷底是反硝化的拐点,也是反硝化与硝化的分界点。

It was demonstrated in a pilot experiment that crushed lava was good carriers in an up-flow biological aerated filter （UBAF）. The removal effieiencies of COD, SS, and turbidity were not affected by effluent recirculation, and moreover the efficiency of nitrification was not enhanced too much due to the effect of low tem- perature during the experiment, but the removal efficiency of total nitrogen （TN） was indeed enhanced by effluent recirculation. Up to effluent recirculation at R = 150% , NO3 converted from nitrification could be fully removed by denitrification. Due to limited nitrification at low temperatures, however, the removal efficiency of TN was enhanced at a limited extent （from 43.8% at R =0 to 69.1% at R = 150% ）. The valley-type DO profile along the bed height （the DO valley at 50 cm）revealed that the DO valley was a turning point for denitrification and also was a boundary of nitrification and denitrification.