Adsorption of Fe3+ ion from Aqueous Solution onto Rice Husk Biocomposite Magnetic Nanoparticle

Rice husk (RH), an agricultural waste, is abundantly available in South Kalimantan. RH has been recycled only for low-value application, although rice husk has the potential to be used as natural fiber. The aim of this research is to produce an adsorbent based on rice husk fiber (RHF) and magnetic nanoparticles (MNPs) and study its performance on Fe3+ ion adsorption, effect on total suspended solid (TSS) and color adsorption. Rice husk was dried (60 mesh), then run through delignification process to eliminate lignin using 1% of NaOH. Rice husk biocomposite (RHB) was produced using a one-pot solvothermal reaction in the presence of RHF and FeCl3⋅6H2O. The surface of RHB was modified by amine group (RBH-MH). As control, the RBH without modification was also produced (RHB-M). The optimum adsorption was reached at pH 5 in a 60-minute period and adsorption capacity for RHB-M and RHB-MH reached 47.63 and 52.46 mg/g, respectively. The RHB-MH also had the capability to adsorb TSS and color, where approximately 87.5% of TSS and 85.81% of color were reduced. Regarding its reusability, the RHB-MH showed a good performance in 4 repeated uses. The addition of amine on the biocomposite may have affected the adsorbent by enhancing its adsorption capacity, reduced TSS and color for reactivity toward a wide range of organic pollutant.