Affiliation:
1. Department of Biotechnology and Chemistry Faculty of Applied and Computer Sciences Vaal University of Technology Private Bag x 021 Vanderbijlpark 1900 South Africa
2. Rand Water Scientific Services Analytical Services Division Vereeniging 1939 South Africa
3. DSI/NRF SARChI: Nanotechnology for Water Department of Chemical Sciences University of Johannesburg Johannesburg, Doornfontein 2028 South Africa
4. Department of Chemistry College of Science Engineering and Technology University of South Africa Florida 1709 South Africa
Abstract
AbstractThe removal of noxious Cr(VI) from water has gained worldwide attention. In this study, biochar derived from macadamia nut shells (MHP) was embedded with iron sulfide (FeS) nanoparticles produced through a solid‐phase reduction of pyrite. The MHP‐FeS composite was evaluated for the adsorption of Cr(VI) and its subsequent reduction to Cr(III). The scanning electron microscope images revealed that the particles were of irregular shape, while the energy dispersive spectroscopy results showed the existence of Fe, S, O, and C atoms. X‐ray diffraction peaks at 2=29.8°, 33.7°, 43.7°, and 53.1° were characteristic of the formation of FeS nanoparticles. A maximum Cr(VI) adsorption capacity of 4.95 mg/g was obtained at pH 3, 60 min, and 25 °C. The higher correlation coefficient (R2>0.873) and lower residual standard error (RSE=1.43) values pointed to the adsorption process favoring Langmuir and pseudo‐second‐order models. As per thermodynamic reaction calculations, the remediation process was spontaneous and endothermic. With further optimization, this material could be a potential adsorbent and reductant for Cr(VI) in water.
Funder
National Research Foundation