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Updated: Sep 29, 2025
09:50
Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
12.8K
Removal of Ammonia Using Persulfate during the Nitrate Electro-Reduction Process
Shuai Yang1, Xinxin Hu2, Xinyu You1
1Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Summary
This study presents a novel method to remove ammonium (NH4+) byproduct from nitrate (NO3-) electro-reduction using sulfate radical (SO4•-)-based advanced oxidation, significantly reducing total nitrogen (TN) in wastewater.
Area of Science:
- Environmental Chemistry
- Water Treatment Technologies
- Electrochemistry
Background:
- Ammonium (NH4+) is a common byproduct of nitrate (NO3-) electro-reduction in advanced sewage treatment, hindering effective total nitrogen (TN) removal.
- Existing methods for TN removal face challenges with byproduct management and overall efficiency.
Purpose of the Study:
- To develop and evaluate a sulfate radical (SO4•-)-based advanced oxidation process for removing NH4+ generated during NO3- electro-reduction.
- To investigate the mechanism of NH4+ oxidation and identify the dominant reactive species involved.
- To assess the feasibility of this method for enhancing TN removal in advanced wastewater treatment.
Main Methods:
- Activation of persulfate (PS) using electrocatalysis with Co/AC0.9-AB0.1 particle electrodes to generate SO4•-.
- Oxidation of NH4+ byproduct in a simulated wastewater matrix.
- Analysis of NH4+ and TN concentrations using relevant analytical techniques.
- Identification of radical species using Electron Spin Resonance (ESR) and quenching experiments.
- Investigation of NO3- reduction pathways using Cyclic Voltammetry (CV).
Main Results:
- Complete oxidation of NH4+ was achieved at a PS dosage of 5.0 mM and 0.1 A current, reducing TN from 9.22 to 0.55 mg/L for an initial NO3--N concentration of 20 mg/L.
- Sulfate radical (SO4•-) was identified as the primary reactive species responsible for NH4+ oxidation, with hydroxyl radicals (•OH) playing a secondary role.
- The presence of common wastewater constituents like phosphate, carbonate, and humic acid inhibited the NH4+ oxidation process.
- Cyclic voltammetry indicated that NO3- reduction predominantly occurred via an indirect pathway mediated by atomic hydrogen (H*).
Conclusions:
- Electrocatalytic activation of persulfate using Co/AC0.9-AB0.1 electrodes is a promising method for oxidizing NH4+ byproduct from NO3- electro-reduction.
- This approach offers an effective strategy for significantly reducing total nitrogen concentrations in advanced sewage treatment.
- Understanding the radical chemistry and reaction pathways is crucial for optimizing the process efficiency.
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