<p>The pollutant removal and bioenergy generation capacities of the non-aerated and aerated electrode-coupled horizontal flow wetlands (filled with stone dust) were assessed. The wetlands received strong (i.e., greater organic-strength) wastewater (landfill leachate) at variable hydraulic loading rates, i.e., 43&#xa0;mm/d to 129&#xa0;mm/d. The horizontal flow wetlands achieved mean organic removal percentage ranges of 96–98% within the applied loading rates. The aerated wetlands exhibited minor improvements in the percentage of biodegradable organic removal (1–3%) compared to the non-aerated system due to the influence of carbon-felt electrodes on electrochemical oxidation. Mean nitrogen, phosphorus, and coliform removal percentages were 86–96%, 89–98%, and 84–97%, respectively. The percentage deviation limits for nutrient and coliform removal improvement within the non-aerated and aerated wetlands were broader, i.e., 3–10%. The continuously aerated wetland achieved 2–7% supplementary nitrogen and coliform removals compared to the intermittently aerated system. The non-aerated and aerated wetlands showed better organic and nitrogen removal under higher loading ranges; however, the phosphorus adsorption capacity of the media was reduced under such loading conditions. The nutrient accretion percentages in the plant tissues were negligible, i.e., ≤ 0.5%. Voltage production ranged between 35 and 70&#xa0;mV; intermittent aeration fulfilled the prerequisites of maximizing bioenergy generation. Integrating an external resistor of 330 Ω produced peak power density ranges of 76 mW/m³-85 mW/m³ across the wetland systems. The continuously aerated electrode-coupled horizontal flow wetland appeared to be a promising technology for treating high-strength organic wastewater.</p> Graphical Abstract <p></p>