This study investigated the mechanism and kinetic modeling of electrolytic degradation of ammonia with Pt/Ti anode. The results show that ammonia oxidation from direct oxidation or indirect oxidation with hydroxyl radicals was slow but can be observed under pH 9 and high initial ammonia concentration of 1,050 mg N L−1. Indirect oxidation with HOCl was the mechanism for the chloride-mediated electrolytic removal of ammonia. In this process, pH between 3 and 9 had little effect on the ammonia removal rate, but current density (j) and chloride concentration ([Cl−]) showed a linear relationship with ammonia removal rate within the range of 3.8–15.4 mA cm−2 and 30–300 mg L−1, respectively. The ammonia removal could be described by a pseudo-zero order kinetics with a mathematic equation of k = 0.0003 × [Cl−] × j − 0.076. Treatment of the actual wastewater effluent from a secondary clarifier in a local wastewater treatment plant showed an ammonia removal rate of 0.8 mg N L−1 h−1 and energy cost of 14 kJ per mg N ammonia.
Research Article|June 01 2013
Electrolytic removal of ammonia from aqueous phase by Pt/Ti anode
Liang Li, Yuanxing Huang, Yan Liu, Yangyang Li; Electrolytic removal of ammonia from aqueous phase by Pt/Ti anode. Water Sci Technol 1 June 2013; 67 (11): 2451–2457. doi: https://doi.org/10.2166/wst.2013.110
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