Green adsorption of oil and grease from wastewater using oil palm leaves activated carbon

Oil and grease contamination in wastewater poses a significant environmental threat due to its persistence and harmful ecological effects. Conventional treatment methods are often limited by high costs, inefficiency, and the risk of secondary pollution. This study investigates the use of oil palm leaves-based activated carbon (OPLAC) as a low-cost, environmentally friendly adsorbent for removing oil and grease from wastewater. A Central Composite Design (CCD) under Response Surface Methodology (RSM) was employed to optimize the process, resulting in 17 batch experiments. The model successfully predicted oil and grease removal efficiency. The regeneration and reusability study has also contributed to great results. It identifies optimal conditions at pH 6, 0.16 g adsorbent dosage, and 44 min contact time to achieve a high removal efficiency of 99.4 %. The Langmuir isotherm and pseudo-second-order kinetic models best describe adsorption data. Both have R² values of 0.99, confirming strong model fit and consistent adsorption behaviour. The regeneration and reusability efficiency of OPLAC was 92 %, 85 % and 77 % with a 15 % loss. These findings highlight the potential of OPLAC as a viable solution for treating oil- and grease-laden wastewater and as a means to valorize agricultural waste, contributing to circular economy practices and sustainable water management.