菌株Paracoccus shandongensis wg2亚硝酸反硝化作用的特性

Characteristics of nitrite denitrification by Paracoccus shandongensis wg2 strain

摘要:

为解决现有技术在亚硝酸盐氮(NO₂^--N)去除中存在的效率偏低、易受高浓度污染物影响等问题，筛选具有高效NO₂^--N去除能力的功能菌株已成为有效的解决方法之一。本文以从环氧丙烷皂化废水活性污泥中分离得到的菌株Paracoccus shandongensis wg2为研究对象，开展氮平衡分析与同位素示踪分析相关研究，证明其脱氮代谢途径属于亚硝酸盐反硝化类型。在缺氧条件下，该菌株对NO₂^--N具有明显去除功能，48 h去除率达98.00%以上。经工艺参数优化，确定最佳脱氮条件为：以葡萄糖为碳源、C/N=5、初始pH 7.0、温度30 ℃及转速170 r/min；在此条件下，菌株wg2可在10 h内将55 mg/L的NO₂^--N完全去除。本研究不仅为含氮废水的生物处理提供了菌种资源，还对处理高浓度亚硝酸盐废水具有重要的实践指导价值。

Abstract:

To address the issues of low efficiency and susceptibility to high-concentration pollutants in nitrite nitrogen (NO₂^--N) removal in existing technologies, screening functional bacterial strains with high NO₂^--N removal capacity has become one of the effective solutions. This study focused on a strain, Paracoccus shandongensis wg2, isolated from activated sludge in the wastewater of propylene oxide saponification, investigating its nitrogen removal mechanism through nitrogen balance analysis and isotopic tracing. The results demonstrated that the strain adopted a nitrogen removal metabolic pathway belonging to the nitrite denitrification type. Under anaerobic conditions, the strain exhibited remarkable nitrite nitrogen (NO₂^--N) removal efficiency, achieving over the elimination rate over 98.00% within 48 h. Through process parameter optimization, the optimal denitrification conditions were determined as follows: glucose as the carbon source, C/N ratio of 5, initial pH 7.0, temperature of 30 ℃, and rotation speed of 170 r/min. Under these optimized conditions, strain wg2 accomplished complete NO₂^--N (55 mg/L) removal within 10 h. This research not only provides a microbial resource for the biological treatment of nitrogen-containing wastewater but also offers significant practical guidance for addressing high-concentration nitrite wastewater.