Nano zero-valent iron loaded corn-straw biochar for efficient removal of hexavalent chromium: remediation performance and interfacial chemical behaviour

Abstract

Loading nano zero-valent iron (nZVI) on corn-straw biochar improved the stability of nZVI and the removal of Cr(vi) in an aqueous system. There happened adsorption, reduction–oxidation and co-precipitation on the composite surface in removal process.

Cost-effective core@shell structured zero-valent iron nanoparticles @ magnetic (nZVI@Fe3O4) for Cr(vi) removal from aqueous solutions: preparation by disproportionation of Fe(ii)

“…It can be hypothesized that the adsorption of Cr( vi ) at high concentrations involves not only electrostatic interactions between nZVI@Fe 3 O 4 and Cr( vi ), but also intra-particle diffusion processes. 2…”

“…It can be hypothesized that the adsorption of Cr(VI) at high concentrations involves not only electrostatic interactions between nZVI@Fe 3 O 4 and Cr(VI), but also intraparticle diffusion processes. 2 To explore the mechanisms of adsorption-diffusion, the intra-particle diffusion model was employed to analyze the kinetic data. Based on the results applied to this model, multistage adsorption of the removal process was noted, suggesting that this process may consist of two steps before reaching equilibrium, as indicated by Fig.…”

“…1 One of the most dangerous contaminants found in polluted sites is chromium, which frequently appears in both trivalent (Cr( iii )) and hexavalent (Cr( vi )) forms. 2 While Cr( vi ) is primarily caused by human activities, such as industrial manufacturing and metallurgy, Cr( iii ) is often insoluble in aqueous solutions and soil. 3 The soluble forms of Cr( vi ), which have a high mobility in nature, are particularly harmful to human health, causing respiratory and eye irritation, dermatitis, gastrointestinal damage, and even cancers like lung and kidney cancer.…”

Chromium toxicity, speciation, and remediation strategies in soil-plant interface: A critical review

“…pekinensis) , fenugreek (Trigonella foenumgraecum) (Raj et al, 2021), lettuce (Lactuca sativa) (Nigussie et al, 2012), radish (Nabavinia et al, 2015), maize (Abbas et al, 2020), rice (Khan S. et al, 2013), barley (Rajput et al, 2021), mustard (Choppala et al, 2015) were substantially reduced by biochar application. In recent days, application of nZVI iron nanoparticles loaded maize straw pyrolyzed biochar significantly effect to minimize the toxicity of Cr in aqueous medium (Wei et al, 2022b). However, pyrolysis temperature, type of feedstock soil type, and the influence of biochar on metal immobilization and assimilation vary within crops (Woldetsadik et al, 2016;Nkoh et al, 2022).…”