Preparation and Characterization of Magnetite Fe3O4-Activated Carbon Composite as Adsorbent Cr(VI) Ion . EKSAKTA [Internet]. 2021 Dec. 30 [cited 2026 Aug. 1];22(4):238-47. Available from: https://eksakta.ppj.unp.ac.id/index.php/eksakta/article/view/284