Abstract

Alfa-Sika Mande Seyf-Laye^1,2,3* , Akpataku Kossitse Venyo^2,3, Tchakala Ibrahim², Djaneye-Boundjou Gbandi³, Bawa Leman Moctar² and Chen Honghan¹

DOI : http://dx.doi.org/10.13005/ojc/360122

The removal of ammonium in wastewater by an electro-oxidation method using Cu, Fe and alloy Cu/Zn electrodes as cathodes and Ti/IrO2 as anode were investigated. The effects of the various operating parameters, including, electro-oxidation duration, temperature, salt (NaCl) and electrode types on the ammonium removal efficiency from synthetic wastewater and real wastewater in batch EC process, were also investigated. The results showed that the maximum removal efficiency was achieved at a current density of 16mA/cm2, at a pH of 5.1, temperature of 30°C and 0.5 g/L NaCl. Among tested materials, Cu/Zn cathode showed the highest ammonium removal rate. The results revealed that the ammonium was removed and 0.2 mg/L of nitrate and 0.023 mg N/L of nitrite were found. Finally, the really wastewater was tested at 40°C in presence of Cu/Zn cathode/ Ti/IrO2 anode with a current density of 18.32 mA/cm2 and the result indicates that electro-oxidation is very efficient and was able to achieve ammonium removal (99.99 %), and COD removal (38 %) in 30 min. During the treatment concentrations of nitrate, nitrite and phosphorous were not detected in the effluent after 30 min. The ammonia removal followed pseudo-first-order kinetics. The electrochemical process can be applied successfully as a final polishing step, or as an alternative method to biological nitrification.

Electrochemical; Electrodes; Nutrient Removal; Ti/IrO2; COD

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