In this work, nitrite was developed to simultaneously remove manganese and ammonia nitrogen from wastewater by the electrochemical method. The characteristics of electrolytic reaction were observed via cyclic voltammograms. Moreover, the mole ratio of nitrite and ammonia nitrogen, voltage, and initial pH value, which affected the removal efficiency of ammonia nitrogen and manganese, were investigated. The results showed that the concentration of ammonia nitrogen in wastewater could be reduced from 120.2 to 6.0 mg L-1, and manganese could be simultaneously removed from 302.4 to 1.5 mg L-1 at initial pH of 8.0, the mole ratios of nitrite and ammonia nitrogen of 1.5:1, and voltage of 20 V direct current electrolysis for 4.0 h. XRD analysis showed that manganese dioxide was deposited on the anode, and manganese was mainly removed in the form of manganese hydroxide precipitation in the cathode chamber.
Keywords: Electrolytic manganese metal wastewater; ammonia nitrogen; electrolysis process; manganese; nitrite.