Synthesis of biomass-based adsorbent from rice husk ash for copper ions adsorption

Abstract

To solve the problems of low utilization of agricultural waste rice husk and heavy metal pollution, this investigation prepared a cheap copper ion adsorbent using rice husk ash (RA). The maximum Cu2+ adsorption capacity was 19.8 mg/g. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and surface area and porosity analyses were used to characterize the composition and structure of the material of silica-depleted rice husk ash (SDRA). The thermodynamics and kinetics of Cu2+ adsorption by SDRA were studied for their relevance to the adsorption mechanism. The adsorption of copper ions by SDRA was in accordance with the Langmuir model and the pseudo-second-order kinetic model. Furthermore, the increases in specific surface area and oxygen-containing functional groups following silica removal were primarily responsible for SDRA’s enhanced adsorption ability. And this is the first time that Cu2+ adsorbent has been prepared from the by-product of the synthesis of silane from rice husk ash. So, its synthesis cost is very low. Moreover, the preparation technique of SDRA is a revolutionary method of adsorbent creation that is both economical and environmentally benign.