Utilization of Riau Peat-Derived Humic Acid Modified with Urea-Formaldehyde for Ni(II) Adsorption: A Geochemical Approach. JTRSS [Internet]. 2026 Sep. 30 [cited 2026 Oct. 12];14(3):800-1. Available from: https://journal.umk.edu.my/index.php/jtrss/article/view/2534