异养硝化细菌Bacillus sp. LY脱氮性能研究

研究了异养硝化细菌Bacillus sp. LY的脱氮性能.结果表明,Bacillus sp. LY是1株具有脱氮能力的异养硝化细菌.在NH⁺₄-N浓度分别为40、80和120 mg/L 3种情况下,120 h反应后,氨氮的去除率分别是100%、85.7%、73.7%,总氮的去除率分别是76.6%、53.4%、64.8%,在菌液初始浓度相同的情况下,随着NH⁺₄-N浓度的增加,细菌的硝化速率以及脱氮速率呈现下降的趋势.有机物浓度是影响Bacillus sp. LY脱氮性能的重要因素,低的有机物浓度会阻碍细菌脱氮性能的发挥,中的有机物浓度会促进细菌脱氮性能的发挥,使体系的脱氮效果达到最佳,高的有机物浓度并不能再次提升细菌的脱氮性能.在Bacillus sp. LY作用下,有机氮经过氨化作用生成氨氮,通过2条可能的途径转化为氮气.1条途径是氨氮先硝化生成亚硝酸盐与硝酸盐,然后反硝化生成氮气.另1条途径是氨氮被氧化生成羟胺,然后脱氢生成氧化亚氮并进一步转化为氮气.这些研究可为开发新型高效生物脱氮工艺提供参考.

Nitrogen Removal by Bacillus sp. LY with Heterotrophic Nitrification Ability

Bacillus sp. LY has the ability of nitrogen removal. Under the NH⁺₄-N load of 40, 80 and 120 mg/L, after 120 hours culture, the NH⁺₄-N removal rate finally was 100%, 85.7%, 73.7%, and the removal rate of TN finally was 76.6%, 53.4%, 64.8%. As the concentration of ammonium improved, the rate of nitrification and the nitrogen removal would decrease under the same concentration of Bacillus sp. LY at the beginning. The concentration of organic material played an important role in the nitrogen removal by Bacillus sp. LY. The low concentration of organic material inhibited the ability of nitrogen removal, and the middle concentration of organic material enhanced its ability of nitrogen removal and reached the optimum nitrogen removal condition, but the high concentration of organic material did not enhance its ability of nitrogen removal again. Organic nitrogen could be transformed to ammonium by Bacillus sp. LY, which was then transformed to N₂ through two possible pathways. One pathway was a nitrification process followed by a denitrification process. The other pathway was that ammonium was first oxidized to hydroxylamine, then dehydrogenized to N₂O and finally transformed to N₂. All these results may contribute to the establishment of new biology process to remove nitrogen with high efficiency.