Clinoptilolite augmented electrocoagulation process for the reduction of high-strength ammonia and color from stabilized landfill leachate

The high-strength leachate produced from sanitary landfill is a serious issue around the world as it poses adverse effects on aquatic life and human health. Physio-chemical technology is one of the promising options as the leachate normally presents in stabilized form and not fully amendable by biological treatment. In this research, the effectiveness of natural zeolite (clinoptilolite) augmented electrocoagulation process (hybrid system) for removing high-strength ammonia (3,442 mg/L) and color (8,427 Pt-Co) from naturally saline (15 ppt) local landfill leachate was investigated. A batch mode laboratory-scale reactor with parallel-monopolar aluminum electrodes attached to a direct current (DC) electric power was used as an electrocoagulation reactor for performance enhancement purpose. Optimum operational conditions of 146 g/L zeolite dosage, 600 A/m² current density, 60 min treatment time, 200 rpm stirring speed, 35 min settling duration, and pH 9 were recorded with up to 70% and 88% removals of ammonia and color, respectively. The estimated overall operational cost was 26.22 $/m³ . The biodegradability of the leachate had improved from 0.05 to 0.27 in all post-treatment processes. The findings revealed the ability of the hybrid process as a viable option in eliminating concentrated ammonia and color in natural saline landfill leachate. PRACTITIONER POINTS: Clinoptilolite was augmented on the electrocoagulation process in saline and stabilized landfill leachate (15 ppt). The high strength NH₃ -N (3,442 mg/L) and color (8,427 Pt-Co) were 70% and 88% removed, respectively. The optimum conditions occurred at 140 g/L zeolite, 60 mA/cm² current density, 60 min, and final pH of 8.20. The biodegradability of the leachate improved from 0.05 to 0.27 after the treatment. This hybrid treatment was simple, faster, and did not require auxiliary electrolyte.