Masai, Winny ChebeniMaingi, Francis M.Makhanu, Maximilla2026-10-082026-10-082026-06-08Masai, W. C., Maingi, F. M. & Makhanu, M. (2026). Oxalic Acid Functionalized Diatomite for Enhanced Lead (II) ions Adsorption from Wastewater. Physical Chemistry, 14(1), pp. 1-9.http://erepository.kibu.ac.ke/handle/123456789/12048Journal ArticleIncreased global demand for batteries and paints has resulted in higher levels of heavy-metal contamination in waterways, harming aquatic life and human health. Lead is of particular concern due to its non-biodegradable nature and persistence at trace levels. Various technologies have been developed for heavy metal removal from wastewater, with adsorption being the most effective and resource-efficient. Information in literature shows that diatomite has the ability to adsorb heavy metal ions from aqueous media but suffers from a low adsorption capacity and specific surface area. This study therefore focused on enhancing the adsorption capacity of low-cost diatomite by functionalizing it with carboxyl groups via oxalic acid. Characterization techniques, including XRF, FT-IR, XRD, and Raman spectroscopy, confirmed the successful functionalization. Batch adsorption experiments demonstrated that functionalized diatomite effectively removed over 80% of Pb (II) ions, with an adsorption capacity of 8.00 mg/g. These findings suggest that functionalized diatomite is a promising potential adsorbent for remediation of heavy metal ions from wastewater.enAdsorptionDiatomiteFunctionalizedLeadWastewaterArticle