异养硝化-好氧反硝化菌脱氮同时降解苯酚特性

研究了异养硝化-好氧反硝化菌Diaphorobacter sp. PDB3去除氨氮同时降解苯酚的特性.在最佳碳氮比7和摇床转速160r/min下,该菌在21h内对初始浓度365mg/L苯酚的降解率达94.9%,总有机碳去除率达90.8%,同时40mg N/L氨氮被完全去除,中间代谢物硝态氮和亚硝态氮逐渐积累并在后期降低.氮平衡分析表明,52.3%的氨氮转化为胞内氮,37.2%转化为氮气,菌株主要通过细胞同化作用和异养硝化-好氧反硝化作用去除氨氮.检测到羟胺氧化酶、硝酸还原酶及亚硝酸还原酶活性,表明菌株PDB3具有完整的异养硝化-好氧反硝化偶联途径.随着苯酚浓度升高,抑制作用增强,脱氮效率降低.

Simultaneous removal of phenol and ammonium by a heterotrophic nitrifiying-aerobic denitrifying bacterium

The simultaneous removal of phenol and ammonium by a heterotrophic nitrifying-aerobic denitrifying bacterium Diaphorobacter sp. PDB3 was investigated. The optimal C/N ratio was 7and the optimal shaking speed was 160r/min. The strain degraded 94.9% of 365mg/L phenol in 21h, and 90.8% of total organic carbon was removed. Simultaneously, ammonium at an initial concentration of 40mg N/L was completely removed. The intermediates nitrate and nitrite accumulated in the early phase and declined in the later phase. The nitrogen balance analysis showed that 52.3% of removed nitrogen was finally transformed to intracellular nitrogen and 37.2% was converted to nitrogen gas. Ammonium was removed mainly through cellular assimilation and heterotrophic nitrification-aerobic denitrification. The detection of hydroxylamine oxidase, nitrate reductase and nitrite reductase activities demonstrated a coupled heterotrophic nitrifying-aerobic denitrifying pathway of strain PDB3. With the increase of phenol concentration, the inhibitory effect increased, leading to lower efficiency of ammonium removal.