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Updated: Apr 23, 2026

Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
Optimization of C/N and current density in a heterotrophic/biofilm-electrode autotrophic denitrification reactor
Shuang Tong1, Nan Chen1, Heng Wang2
1Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing 100083, China; School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, China.
Abstract:
In this study, central composite design (CCD) and response surface methodology (RSM) were applied to optimize the C/N and current density in a heterotrophic/biofilm-electrode autotrophic denitrification reactor (HAD-BER). Results showed that nitrate could be effectively reduced over a wide range of C/Ns (0.84-1.3535) and current densities (96.8-370.0 mA/m(2)); however, an optimum C/N of 1.13 and optimum current density of 239.6 mA/m(2) were obtained by RSM. Moreover, the HAD-BER performance under the optimum conditions resulted in almost 100% nitrate-N removal efficiency and low nitrite-N and ammonia-N accumulation. Furthermore, under the optimum conditions, H2 generated from water electrolysis matched the CO2 produced by heterotrophic denitrification by stoichiometric calculation. Therefore, CCD and RSM could be used to acquire optimum operational conditions and improve the nitrate removal efficiency and energy consumption in the HAD-BER.
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