Magnetic Palm Kernel Shell Biochar as an Efficient Adsorbent for Organic Pollutants

Abstract

Water contamination by organic pollutants is a serious hazard to human health. In order to remove salicylic acid (SA) and 4-nitroaniline (4-NA) from aqueous solutions, this work developed magnetically recoverable biochar from palm kernel shell using a co-precipitation approach. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to analyze the synthesized magnetic biochar, revealing its porous structure and successful magnetization with Fe₃O₄ particles. For both pollutants, the MBC showed high removal efficiencies—above 90% under ideal circumstances.  The Langmuir isotherm model yielded maximal adsorption capacities of 144 mg/g for 4-NA and 155 mg/g for SA. The equilibrium data were best explained by the Langmuir isotherm, indicating monolayer adsorption on a homogeneous surface. Additionally, the study showed that adsorption was strongly pH-dependent, with 4-NA being best removed at a pH that was almost neutral. The biochar's magnetic characteristic made it simple to separate it from treated water using an external magnet. These results suggest that magnetic palm kernel shell biochar is a possible substitute for traditional activated carbon as a highly efficient, inexpensive, and readily separable adsorbent for treating water contaminated with developing organic contaminants.