Organic matter removal of landfill leachate using integrated electrocoagulation-ultrasonic method

The utilization of hybrid treatment technologies has been recognized as one of the treatment methods conducted to enhance the efficiency of wastewater treatment due to the various challenges such as the high concentration of pollutants and the limited ability of a single treatment process. Leachate from Pulau Burung Sanitary Landfill (PBSL) has been categorized as poor biodegradability leachate and it is composed of high dissolved organic matter, inorganic components, and toxic substances. In this study, an integrated treatment between electrocoagulation (EC) and ultrasonic (US) was introduced to evaluate the effectiveness of the hybrid treatment process in landfill leachate treatment of organic matter removal in terms of COD compared with a single treatment with different operating conditions of voltage, treatment time, and distance of electrode. Other than that, the effect of the control factors on the weight loss of electrodes was also investigated. The maximum COD reduction from both single EC and combined EC-US methods have achieved the same best operating condition which are potential of 10 V, treatment time of 25 min, and electrode distance of 2 cm, but the combined EC-US treatment (61.13%) provide better removal of COD compared with the treatment process of a single EC method (37.51%). On the other hand, the highest weight loss of the electrode was observed at the anode (Al-21.60%) with the same operating conditions for the best removal efficiency in the EC-US process. It is found that the cathode (Fe) experienced a slight increase in the final weight of the electrode due to the hydrolyzation reaction. Hence, this research work demonstrated that the utilization of combined EC-US treatment significantly enhanced the removal of COD from leachate compared with the single EC method.