* Corresponding author: Elsherif, Khaled Muftah  E-mail: elsherif27@yahoo.com © 2024 by SPC (Sami Publishing Company) Advanced Journal of Chemistry, Section A journal homepage: www.ajchem-a.com Original Research Article Adsorption of Cd(II) onto Olive Stones Powder Biosorbent: Isotherms and Kinetic Studies Khaled Muftah Elsherif 1 * , Rima Abdessalem Abdullah Saad 2 , Abdunaser Mabrok Ewlad- Ahmed 2 , Abdullah Amhimmid Treban 2 , Abdulrhman Mohammed Iqneebir 2 1 Libyan Authority for Scientific Research, Tripoli, Libya 2 Chemistry Department, Faculty of Arts and Science Msallata, ElMergib University, Al-Khoms, Libya A R T I C L E I N F O A B S T R A C T Article history Submitted: 11 September 2023 Revised: 08 October 2023 Accepted: 30 October 2023 Available online: 31 October 2023 Manuscript ID: AJCA-2308-1415 Checked for Plagiarism: Yes Language editor: Dr. Fatimah Ramezani Editor who approved publication: Dr. Milad Ghani DOI: 10.48309/AJCA.2024.415865.1415 Cadmium (Cd) is a hazardous heavy metal that presents substantial hazards to both human well-being and the ecosystem. To address this issue, biosorption, an environmentally friendly and cost-effective technique, utilizes biological materials to capture metal ions from contaminated water. In our research, we focused on developing a biosorbent material using olive stones powder (OSP), which is a readily available agricultural waste. Our study aimed to assess the OSP effectiveness in the process of extracting Cd(II) ions from various aqueous solutions under diverse experimental parameters. In addition, we examined the adsorption kinetics and isotherms using various models. The findings revealed that OSP exhibited a strong adsorption capacity and affinity for Cd(II) ions, with a maximum value of 20.245 mg/g achieved at pH 6, an OSP dosage of 0.05 g, and a contact time of 30 minutes. The adsorption process adhered to the pseudo-second-order kinetic model and conformed to the Freundlich isotherm model, indicating the formation of multiple layers and the presence of heterogeneous surface sites. Furthermore, comparing the maximum capacity value (Qm) of OSP obtained in our study with previous research, it falls within the intermediate range. Overall, our study demonstrated the potential of OSP as a highly effective biosorbent material for effectively eliminating Cd(II) ions from aqueous solutions. K E Y W O R D S Adsorption Cadmium Olive stones Isotherms Kinetics Advanced Journal of Chemistry, Section A, 2024, 7(1), 59-74