School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China.
School of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong, China.
Bioresour Technol. 2018 Mar;252:134-142. doi: 10.1016/j.biortech.2017.12.078. Epub 2017 Dec 26.
Bioelectrochemical enhanced nitrate removal in wastewater with high total nitrogen and low organic carbon was electrochemically investigated focusing on the relationship between biochemical and electrochemical nitrogen cycles. Under optimized external voltage of -0.6 V, apparent nitrate removal rate of bioelectrochemical denitrification was 76% higher than normal biofilm denitrification. And with the introduction of biofilm on the electrode, new reduction peak of NO, much larger current density, and 0.4 V positively shift of on-set potential of nitrate reduction reaction were observed, suggesting a synergy of electrochemical reaction and biological reaction through enhanced electrochemical reduction of intermediate products from biological process. Oxygen reduction reaction could not be avoided during nitrogen electrochemical reduction reaction since their similar reduction potential. But it led to decrease of oxygen concentration and therefore contribute to biological denitrification. Bacteria community tests also supported a dominant bacteria which could denitrify and use external electron.
本研究聚焦于生化和电化学氮循环之间的关系，采用电化学方法对高总氮、低有机碳废水中的硝酸盐进行生物电化学去除。在优化的外部电压-0.6 V 下，生物电化学反硝化的表观硝酸盐去除率比普通生物膜反硝化高 76%。同时，在电极上引入生物膜后，观察到新的 NO 还原峰、更大的电流密度以及硝酸盐还原反应起始电位正向移动 0.4 V，这表明电化学反应和生物反应之间存在协同作用，通过增强生物过程中间产物的电化学还原来实现。由于还原电位相似，在进行氮的电化学还原反应时，不可避免地会发生氧还原反应。但这会导致氧浓度降低，从而有利于生物反硝化。细菌群落测试也支持了一种可以反硝化和利用外部电子的优势菌。
