Chitosan-Modified Magnetic Biochar from Apricot Kernel Cake for Efficient Removal of Pb (II) and Cd (II) from Wastewater

Abstract

This study explored the potential of utilizing chitosan-enhanced magnetic biochar produced from apricot kernel cake (CMBA) to remove heavy metals from water-based solutions. The synthesized CMBA's characteristics as an effective adsorbent for Pb²⁺ and Cd²⁺ were evaluated based on data analysis. The study evaluated various physicochemical modifications, such as surface morphology, porosity, specific surface area, chemical composition, valence states, and magnetic properties, to assess the composite's effectiveness for removing heavy metals from wastewater. The adsorption performance of the magnetic biochar (MBA) was significantly enhanced by chitosan doping. The saturation magnetization of CMBA was 20.94 emu/g, indicating paramagnetic properties. Furthermore, the facile magnetic recovery of CMBA from the aqueous solution after adsorption was confirmed using an external magnetic field. The kinetic characteristics of heavy metal ions on CMBA were determined to be a monolayer physisorption process, as confirmed by Langmuir analysis. The determined maximum adsorption capacities for Pb²⁺ and Cd²⁺ were 150.9 and 149.3 mg/g, respectively. The electrochemical method was employed to quantify residual metal ions after adsorption, with calibration curves established individually and simultaneously for accuracy. The CMBA biochar with partial chitosan channels shows strong potential for wastewater treatment and broader separation applications.