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 minutes 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 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. • Innovative Adsorbent: Demonstrates the use of oil palm leaf activated carbon (OPLAC) as a novel and eco-friendly adsorbent for oil and grease removal from wastewater. • High Adsorption Efficiency: Achieved 99.4% adsorption efficiency under optimized conditions using Response Surface Methodology (RSM). • Optimized Conditions: Identified optimal parameters: pH 6, adsorbent dosage of 0.16 g, and contact time of 44 minutes. • Model Validation: Langmuir isotherm and Pseudo-second-order kinetic models exhibited strong correlation with R² values of 0.99. • Sustainability Impact: Provides a sustainable solution for wastewater treatment while repurposing agricultural waste and reducing environmental biowaste.