<p>Fresh landfill leachate contains extremely high pollutant loads and must be effectively treated before discharge. Fresh leachate is characterized by a dark brown color with high concentrations of Chemical Oxygen Demand (COD), which should be treated economically before being discharged to the environment. This study investigates a sequential electrocoagulation–adsorption process for the treatment of high-strength fresh landfill leachate collected from a municipal solid waste site in Karachi, Pakistan. The raw leachate had approximately 11,400&#xa0;mg L⁻¹ of COD and the Leachate Pollution Index (LPI) of 24.7, far exceeding local discharge criteria (COD = 150&#xa0;mg L⁻¹, LPI = 7.4). In the first stage, a custom four-plate electrocoagulation (EC) reactor removed about 78.5% of the COD and eliminated the dark color of leachate to acceptable levels. However, electrocoagulation alone could not meet the COD discharge standards set by the Government of Sindh under the legal framework of&#xa0;Sindh Environmental Quality Standards (SEQSs, 2016) for municipal effluents. Thus, the electrocoagulation-treated effluent received post-treatment&#xa0;adsorption in separate runs&#xa0;with granular activated carbon (GAC) and biochar. The biochar adsorption reduced COD to 30&#xa0;mg L⁻¹ (99.7% overall removal), outperforming GAC (COD 112&#xa0;mg L⁻¹, 99.0% removal). The integrated electrocoagulation–adsorption process successfully met discharge standards, and a techno-economic analysis indicated it is cost-effective, with an estimated treatment cost as low as 0.88 US$ m⁻³ when solar energy is utilized. Overall, this study demonstrates a techno-economically feasible, efficient, and comprehensive solution for fresh&#xa0;landfill leachate treatment. It may serve as a valuable reference for landfill operators, environmentalists, and policymakers, particularly in resource-limited regions.</p> Graphical Abstract <p></p>