有氧条件下生物过滤法脱氮研究

NITROGEN REMOVAL BY BIOLOGICAL FILTRATION UNDER AEROBIC CONDITION

采用生物过滤法,以醋酸钠为外加碳源,探讨了有氧条件下反硝化脱氮的可行性。研究表明,通过向配制水中通入由N2+O2组成的合成气体,能方便地控制水体中溶解氧的浓度。在向配制水中通入含有少量O2的合成气后,系统中的溶解氧浓度下降比不通任何气体时下降还快。随着溶解氧含量逐渐提升,系统反硝化脱氮效果并未受到明显影响。当溶解氧达到6.4mg/L时,系统仍然具有反硝化作用,只是硝酸盐浓度下降速度比低溶解氧条件下缓慢,但是脱氮效率仍然可达85%左右。结果显示,采用生物过滤系统以及实验室培养得到的两种微生物,在一定溶解氧条件下,溶解氧对系统反硝化脱氮能力影响有限。

The feasibility ofdenitrification in a biofilter was explored under aerobic condition with sodium acetate as carbon source. Dissolved oxygen concentration could be controlled conveniently when the simulated wastewater was aerated with synthetic gas composed of N2 and O2 when the synthetic gas contained small amount of O2,dissolved oxygen（DO） content in the water lowered more rapidly than in the water without any gas; as DO content rose gradually, the system＇s denitrification effect had no obvious influence. When DO reached to 6.4mg/L,the system had denitrification action still; only nitrate concentration lowered quicker than it did under the condition of low DO,but nitrogen removal rate could reach to about 85% still. The experimental results showed that adopting both microorganisms cultured in bio-filter system and laboratory, and a certain DO content, DO had little influence on the system＇s denitrification ability.