Removal of Ammoniacal Nitrogen from Old Leachate using Batch Electrocoagulation with Vibration-induced Electrode Plate

Abstract This study investigated the effectiveness of batch electrocoagulation with vibration-induced electrode plates in enhancing the role of gas bubbles in the removal of ammoniacal nitrogen (NH3-N) from landfill leachate. The experimental setup, which consisted of an electrocoagulation reactor and electrode plates attached to a vibrator motor and connected to a DC-power supply, was employed to determine the effects of the vibration intensity, initial pH, operating time and current intensity on the percentage removal of NH3-N. The results revealed that the removal of NH3-N was optimum when the plates vibrated at 2.8 V. Further analysis at this optimum vibration intensity showed that the percentage removal of NH3-N was enhanced at an initial pH of 10 for both the vibrating and stationary plates. While the treatment with stationary plates showed an increase in the percentage removal of NH3-N with time, an optimum time of 35 minutes was achieved for the treatment using the vibration-induced plates. The results showed that the higher the current intensity, the higher the removal of NH3-N. Electrocoagulation with both the stationary plates and vibration-induced plates was able to achieve 40% and 50% removal of NH3-N, respectively at a current intensity of 4.5 A. The percentage removal of NH3-N through electrocoagulation with the vibration-induced electrode plates was found to have improved compared with the use of stationary plates due to the better dispersion of gas bubbles, which reduced the attachment and accumulation of bubbles on the surface of the electrode plates, thereby enhancing the ionic transfer between the plates.