Utilization of Response Surface Methodology to Optimize Ammoniacal Nitrogen Adsorption Efficiency from Palm Oil Mill Secondary Effluent Using Palm Empty Fruit Bunch as Adsorbent

Abstract

The disposal of ammonia-laden wastewater from the palm oil industry presents a significant environmental challenge leading to water quality deterioration and adverse effects on aquatic ecosystems. The conventional methods for ammonia removal are often costly and complex necessitating the exploration of alternative solutions. This study investigates the use of palm empty fruit bunch (EFB) biochar as a sustainable adsorbent for the removal of ammonia from palm oil mill secondary effluent (POMSE). Employing Response Surface Methodology (RSM) with a Central Composite Design (CCD), the study has optimized key parameters including adsorbent dosage, initial ammonia concentration and carbonization temperature. The results demonstrated that palm EFB biochar effectively reduced ammonia levels, achieving removal efficiencies of approximately 30% at a dosage of 2 g/L and up to 43% at 4 g/L under optimal conditions (initial ammonia concentration of 292.5 mg/L and carbonization temperature of 500°C). The adsorption process conformed to the Langmuir isotherm model, indicating monolayer adsorption on a homogeneous surface. Characterization techniques such as Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy confirmed the structural integrity and functional interactions of the biochar with ammonia molecules. Additionally, the study explored the regeneration capabilities of the palm EFB biochar, highlighting its potential for repeated use in wastewater treatment applications. This research underscores the viability of utilizing agricultural waste as an effective and sustainable solution for ammonia removal, contributing to environmental sustainability and resource recovery in the palm oil industry.