Magnetic Hydroxyapatite for Batch Adsorption of Heavy Metals

¹ Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610 Perak Darul Ridzuan, Malaysia
² Faculty of Civil Engineering, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan, Malaysia
³ Center for Advanced Integrated Membrane System (AIMS), Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610 Perak Darul Ridzuan, Malaysia

^* Corresponding author: norashikin7349@uitm.edu.my

Abstract

In this work, magnetic hydroxyapatite or hydroxyapatite-iron (III) oxide (HAp-Fe₃O₄) composite was used as the adsorbent of heavy metals and the performance was evaluated using the batch test. The presence of heavy metals in the effluent from wastewater discharge can be toxic to many organisms and can even lead to eye burns. Therefore, hydroxyapatite synthesized from the chemical precipitation of calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions is used to remove heavy metal in aqueous media. Magnetic properties of Fe₃O₄ can help prevent formation of secondary pollutants caused by the loss of adsorbent. The synthesized HAp-Fe₃O₄ can remove cadmium, zinc and lead effectively, which is up to 90% removal. Reusability study shows that the adsorbent could retain heavy metal ions even after four cycles. The percentage removal of heavy metals maintains at around 80% after four times of usage. The composite of HAp-Fe₃O₄ demonstrates good performance and stability which is beneficial for heavy metal removal in the future.