title: Novel chitosan/PVA/zerovalent iron biopolymeric nanofibers with enhanced arsenic removal applications.
abstract: Enhanced removal application of both forms of inorganic arsenic from arsenic-contaminated aquifers at near-neutral pH was studied using a novel electrospun chitosan/PVA/zerovalent iron (CPZ) nanofibrous mat. CPZ was carefully examined using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), atomic fluorescence spectroscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). Application of the adsorbent towards the removal of total inorganic arsenic in batch mode has also been studied. A suitable mechanism for the adsorption has also been discussed. CPZ nanofibers mat was found capable to remove 200.0±10.0 mg g(-1) of As(V) and 142.9±7.2 mg g(-1) of As(III) from aqueous solution of pH 7.0 at ambient condition. Addition of ethylenediaminetetraacetic acid (EDTA) enabled the stability of iron in zerovalent state (ZVI). Enhanced capacity of the fibrous mat could be attributed to the high surface area of the fibers, presence of ZVI, and presence of functional groups such as amino, carboxyl, and hydroxyl groups of the chitosan and EDTA. Both Langmuir and Freundlich adsorption isotherms were applicable to describe the removal process. The possible mechanism of adsorption has been explained in terms of electrostatic attraction between the protonated amino groups of chitosan/arsenate ions and oxidation of arsenite to arsenate by Fentons generated from ZVI and subsequent complexation of the arsenate with the oxidized iron. These CPZ nanofibrous mats has been prepared with environmentally benign naturally occurring biodegradable biopolymer chitosan, which offers unique advantage in the removal of arsenic from contaminated groundwater.
authors.affiliation: Centre for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, U.P., 208016, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Chauhan
authors.forename: Jaya
authors.initials: J
authors.lastname: Dwivedi
authors.forename: Nalini
authors.initials: N
authors.lastname: Sankararamakrishnan
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D060587:Groundwater / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D057139:Nanofibers / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D014874:Water Pollutants, Chemical; D011142:Polyvinyl Alcohol; D048271:Chitosan; D007501:Iron; D001151:Arsenic
references.citation: Sci Total Environ. 2009 Sep 1;407(18):4994-5000
references.pmid: 19545888
references.citation: J Biomater Sci Polym Ed. 2004;15(6):797-811
references.pmid: 15255527
references.citation: Talanta. 2002 Aug 16;58(1):3-22
references.pmid: 18968730
references.citation: Biotechnol Bioeng. 2007 Aug 15;97(6):1357-65
references.pmid: 17274060
references.citation: ACS Nano. 2010 Jul 27;4(7):3979-86
references.pmid: 20552997
references.citation: Environ Sci Technol. 2008 Oct 1;42(19):7424-30
references.pmid: 18939581
references.citation: Water Res. 2007 May;41(9):1851-8
references.pmid: 17367839
references.citation: J Environ Sci Health A Tox Hazard Subst Environ Eng. 2012;47(6):847-53
references.pmid: 22423991
references.citation: Environ Sci Technol. 2005 Apr 1;39(7):2120-7
references.pmid: 15871246
references.citation: Water Res. 2002 Dec;36(20):5141-55
references.pmid: 12448563
references.citation: Chemosphere. 2012 Jan;86(2):150-5
references.pmid: 22079302
references.citation: Chemosphere. 2004 Jun;55(9):1245-52
references.pmid: 15081765
references.citation: ACS Appl Mater Interfaces. 2012 Oct 24;4(10):5353-9
references.pmid: 22974085
references.citation: Membranes (Basel). 2011 Aug 22;1(3):232-48
references.pmid: 24957734
references.citation: Water Res. 2005 Mar;39(5):763-70
references.pmid: 15743620
references.citation: Chem Eng J. 2012 May 1;189-190:237-243
references.pmid: 22539917
references.citation: Ecotoxicol Environ Saf. 2010 Oct;73(7):1748-54
references.pmid: 20708265
references.citation: Chemosphere. 2005 Jul;60(3):389-97
references.pmid: 15924958
references.citation: Biomacromolecules. 2001 Fall;2(3):765-72
references.pmid: 11710030
references.citation: J Colloid Interface Sci. 2012 Jun 1;375(1):154-9
references.pmid: 22424815
references.citation: J Biomater Sci Polym Ed. 2004;15(3):279-96
references.pmid: 15147162
references.citation: Environ Sci Technol. 2001 Nov 15;35(22):4562-8
references.pmid: 11757617
references.citation: Angew Chem Int Ed Engl. 2006 Dec 4;45(47):7896-936
references.pmid: 17131371
references.citation: J Hazard Mater. 2011 Nov 30;196:270-7
references.pmid: 21943920
references.citation: Environ Sci Technol. 2005 Mar 1;39(5):1291-8
references.pmid: 15787369
references.citation: Water Res. 2009 Aug;43(15):3862-70
references.pmid: 19577786
references.citation: J Hazard Mater. 2007 Apr 2;142(1-2):1-53
references.pmid: 17324507