title: The mechanism for degrading Orange II based on adsorption and reduction by ion-based nanoparticles synthesized by grape leaf extract.
abstract: Biomolecules taken from plant extracts have often been used in the single-step synthesis of iron-based nanoparticles (Fe NPs) due to their low cost, environmental safety and sustainable properties. However, the composition of Fe NPs and the degradation mechanism of organic contaminants by them are limited because these are linked to the reactivity of Fe NPs. In this study, Fe NPs synthesized by grape leaf extract served to remove Orange II. Batch experiments showed that more than 92% of Orange II was removed by Fe NPs at high temperature based on adsorption and reduction and confirmed by kinetic studies. To understand the role of Fe NPs in the removal process of azo dye, surface analysis via X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed, showing that the Fe NPs were composed of biomolecules, hydrous iron oxides and Fe(0), thus providing evidence for the adsorption of Orange II onto hydrous iron oxides and its reduction by Fe(0). Degraded products such as 2-naphthol were identified using LC-MS analysis. A degradation mechanism based on asymmetrical azo bond cleavage for the removal of Orange II was proposed.
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Fang
authors.initials: F
authors.lastname: Luo
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Die
authors.initials: D
authors.lastname: Yang
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: zuliang.chen@unisa.edu.au.
authors.forename: Zuliang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Mallavarapu
authors.initials: M
authors.lastname: Megharaj
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Ravendra
authors.initials: R
authors.lastname: Naidu
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000302:isolation & purification*; D001557:Benzenesulfonates / Q000302:isolation & purification*; D004785:Environmental Pollutants / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D055772:Green Chemistry Technology; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D027843:Vitis / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004785:Environmental Pollutants; D010936:Plant Extracts; C014722:2-naphthol orange
keywords: Adsorption; Fe NPs; LC–MS; Orange II; Reduction; XPS