Efficient nitrogen removal by simultaneous photoelectrocatalytic oxidation and electrochemically active biofilm denitrification. (20th April 2016)

• Record Type: Journal Article
• Authors: Wang, Qi; Xu, Jianjia; Ge, Yaohua; Zhang, Yi; Feng, Huajun; Cong, Yanqing
• Is Part Of: Electrochimica acta. Volume 198(2016)
• Page Start: 165
• Page End: 173
• Publication Date: 2016-04-20
• Subjects: Photoelectrocatalytic oxidation -- Autotrophic denitrification biofilm -- Nitrogen removal -- Ammonium -- Nitrate; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.03.011
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Abstract: A novel nitrogen removal strategy, the combined photoelectrocatalytic oxidation and autotrophic biofilm denitrification, was developed to achieve simultaneous NH4 + -N oxidation and NO3 − -N reduction in a single reactor. AgI/TiO2 -NTs and autotrophic denitrifying biofilm were used as anode and cathode, respectively. NH4 + -N oxidation efficiency was enhanced by 3 times after the introduction of visible light. Moreover, NO3 − -N and NO2 − -N generated in the process of NH4 + -N oxidation could be further removed by biocathode. Applied voltage and pH have significant effects on nitrogen removal. The NO3 − -N and NH4 + -N removal efficiencies gradually increased from 27.2% to 74.3% and 60.0% to 83.1%, respectively, when the voltage increased from 1.0 V to 3.0 V. Neutral or slightly alkaline condition was favorable on account of the autotrophic denitrifying biofilm. The optimum TN (TNNH4 + -N + NO3 − -N + NO2 − -N) removal efficiency was up to 89.6% at pH 8 with 3.0 V voltage.