SA-CMC固定反硝化细菌好氧反硝化性能探究

Study on the Aerobic Denitrification Performance of SA-CMC with Immobilized Denitrifying Bacteria

为扩大反硝化菌应用和抗逆性,以海藻酸钠(SA)和羧甲基纤维素钠(CMC)为载体、用CaCl_(2)交联,联合包埋脱氮副球菌,制作反硝化菌剂,探究有氧条件下,菌剂的好氧反硝化性能。结果表明,有氧条件下,所得菌剂对硝态氮的还原能力显著高于游离态菌(总氮氧化物去除率分别为95.6%和9.6%)。CMC含量升高能显著提高菌剂好氧反硝化效果并降低亚硝酸盐转化率,但过高导致菌剂抗压性能下降,以质量分数2%为宜;SA含量对凝胶小球形态影响显著,含量低小球难以成型,含量高则拖尾严重,反硝化能力下降,以质量分数3%为佳;CaCl_(2)含量过高,所得凝胶小球密实、影响传质,反硝化能力下降,以质量分数1%为宜。CMC-SA联合固定反硝化菌可实现有氧条件下的反硝化。

To expand the application range and strengthening the resistance of denitrifying bacteria,sodium alginate(SA)and sodium carboxymethyl cellulose(CMC)as the carrier materials,and CaCl_(2) as crosslinker,co-embed Paracoccus denitrificans to make denitrifying bacteria agent,and the aerobic denitrification performance of bacteria agent under aerobic conditions was explore.The results showed that,under aerobic conditions,the reduction ability of the obtained bacterial agent to nitrate nitrogen was significantly higher than that of free bacteria(the removal efficiency of total nitrogen oxides was 95.6% and 9.6%,respectively).The increase of CMC content could significantly improve the aerobic denitrification effect of bacterial agents and reduce the conversion rate of nitrite,but too high would cause the compression performance of the bacterial agent to decrease,and the appropriate mass fraction was 2%.The SA content had a significant effect on the morphology of the gel pellets,the pellets with low content were difficult to form,and the high content would cause serious tailing and reduce the denitrification ability,the appropriate mass fraction was 3%.The content of CaCl_(2) was too high,the resulting gel pellets would be dense,which would affect mass transfer and decrease the denitrification capacity,the appropriate mass fraction was 1%.CMC-SA combined with immobilizied denitrifying bacteria can achieve denitrification under aerobic conditions.