School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
Department of Building, Civil, and Environmental Engineering, Concordia University, 1455 de Maisonneuve Blvd. W, Montreal, Quebec, Canada.
Bioresour Technol. 2019 Nov;291:121816. doi: 10.1016/j.biortech.2019.121816. Epub 2019 Jul 16.
Polyoxometalates (POMs) used in chemical catalysis field were first explored their effect on the denitrification process. Experiments demonstrated that NO-N reduction rate with 0.05 mM phosphomolybdic acid (PMo) was approximately 3.93-fold higher than the PMo-free system. Simultaneously, PMo also had positive effect on NO-N reduction. Compared with the PMo-free system, the solution resistance and oxidation-reduction potential were decreased, and the activation energy (E) was reduced by 51.84 kJ/mol. Besides, electron conductive substances in extracellular polymeric substances were stimulated by PMo. NADH and riboflavin were enhanced to increase denitrification electron transport system activity. Higher microbial diversity and enrichment of Salmonella were observed in the PMo-supplemented system. Based on the above analysis, the catalyzing mechanisms of PMo are proposed that PMo made it easier for electron transferring from electron donor to electron acceptor and shifted bacterial community structure. These findings may provide a promising strategy for nitrogen wastewater treatment.
多金属氧酸盐（POMs）在化学催化领域的应用首次被探索用于研究其对反硝化过程的影响。实验表明，添加 0.05 mM 磷钼酸（PMo）后，NO-N 的还原速率比无 PMo 系统提高了约 3.93 倍。同时，PMo 对 NO-N 的还原也有积极的影响。与无 PMo 系统相比，溶液电阻和氧化还原电位降低，活化能（E）降低了 51.84 kJ/mol。此外，PMo 刺激了细胞外聚合物中的电子导电物质。NADH 和核黄素增加，从而提高了反硝化电子传递系统的活性。在添加 PMo 的系统中，观察到微生物多样性更高，沙门氏菌富集。基于上述分析，提出了 PMo 的催化机制，即 PMo 使电子更容易从电子供体转移到电子受体，并改变了细菌群落结构。这些发现可能为含氮废水处理提供了一种很有前景的策略。
