title: Removal of Arsenic (III, V) from aqueous solution by nanoscale zero-valent iron stabilized with starch and carboxymethyl cellulose.
abstract: In this work, synthetic nanoscale zerovalent iron (NZVI) stabilized with two polymers, Starch and Carboxymethyl cellulose (CMC) were examined and compared for their ability in removing As (III) and As (V) from aqueous solutions as the most promising iron nanoparticles form for arsenic removal. Batch operations were conducted with different process parameters such as contact time, nanoparticles concentration, initial arsenic concentration and pH. Results revealed that starch stabilized particles (S-nZVI) presented an outstanding ability to remove both arsenate and arsenite and displayed ~ 36.5% greater removal for As (V) and 30% for As (III) in comparison with CMC-stabilized nanoparticles (C-nZVI). However, from the particle stabilization viewpoint, there is a clear trade off to choosing the best stabilized nanoparticles form. Removal efficiency was enhanced with increasing the contact time and iron loading but reduced with increasing initial As (III, V) concentrations and pH. Almost complete removal of arsenic (up to 500 μg/L) was achieved in just 5 min when the S-nZVI mass concentration was 0.3 g/L and initial solution pH of 7 ± 0.1. The maximum removal efficiency of both arsenic species was obtained at pH = 5 ± 0.1 and starched nanoparticles was effective in slightly acidic and natural pH values. The adsorption kinetics fitted well with pseudo-second-order model and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 14 mg/g for arsenic (V), and 12.2 mg/g for arsenic (III). It could be concluded that starch stabilized Fe(0) nanoparticles showed remarkable potential for As (III, V) removal from aqueous solution e.g. contaminated water.
authors.affiliation: Department of Environmental Health Engineering, Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran ; Center for Water Quality Research (CWQR), Institute for Environmental Research (IER) and department of Environmental Health Engineering, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mosaferi
authors.affiliation: Department of Environmental Health Engineering, School of Health, Center of Student Researches, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Nemati
authors.affiliation: Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Khataee
authors.affiliation: Center for Water Quality Research (CWQR), Institute for Environmental Research (IER) and department of Environmental Health Engineering, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Nasseri
authors.affiliation: Department of Environmental Health Engineering, School of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Ahmad Asl
authors.initials: AA
authors.lastname: Hashemi
keywords: Adsorption; Arsenic; Metallic iron; Nanoparticles; Water purification