Activated Opuntia ficus-indica as an efficient adsorbent for iodine and heavy metals Cr(III), Cu(II) and Ni(II) ions uptake for wastewater treatment

Abstract

Water pollution by heavy metals or iodine is a serious environmental issue that poses a threat to human health and ecosystems. Therefore, there is a need for developing efficient and low-cost methods for removing heavy metals and iodine from water sources. Activated Opuntia ficus-indica (AOFI) has been used for various purposes such as food, medicine, cosmetics, biofuel, and soil stabilization. The aim of this study was to investigate the feasibility of using AOFI as an adsorbent for removing heavy metals; e.g. Cr(III), Pb(II), and Cu(II) and iodine from water. The leaves of AOFI that were collected from Al-Baha city, KSA, were carbonized and characterized using FTIR spectroscopy and TGA analysis. Then uptake experiments were performed to evaluate the effects of various parameters such as pH, contact time, initial concentration, and temperature on the removal uptake by AOFI. Also the thermodynamic and kinetic parameters of the adsorption process had been calculated. The adsorption capacity of AOFI and OFI against iodine, Cr(III), Pb(II), and Cu(II) had been calculated. The results showed that; AOFI has adsorption capacity 1.14, 1.14, and 1.16 times higher than OFI, for Cr(III), Pb(II), and Cu(II), respectively, and 1.05 times higher than OFI, for iodine uptake. The findings indicated that AOFI exhibited remarkable efficacy in the metal ions uptake, achieving uptake efficiency up to 70%. Additionally, AOFI demonstrated notable efficiency in iodine uptake, reaching up to 60%. These results underscore the high uptake efficiency of AOFI for both metal ions and iodine, emphasizing its potential as an effective adsorbent for water treatment applications. This study is novel because it is the first to report the adsorption of heavy metals; such as Cr(III), Pb(II), and Cu(II) and iodine by AOFI.