Item


Montmorillonite-supported nanoscale zero-valent iron for removal of arsenic from aqueous solution: Kinetics and mechanism

Montmorillonite-supported nanoscale zero-valent iron (Mt-nZVI) has been synthesized to remove inorganic arsenic (As) from aqueous solutions. BET, SEM, EDX, XRD and XPS were used to characterize the clay-supported material which consists mainly of core shell Fe(0) structure with an outer oxide/hydroxide shell. The dispersion of nZVI onto montmorillonite was found to be increased with decreasing tendency to agglomerate into larger particles. Batch experiments revealed that adsorption kinetics followed pseudo-second order rate equation with high affinity towards both As(III) and As(V) over a wide pH range (4-8) which was decreased at pH>9. The maximum adsorption capacity calculated from the Langmuir adsorption isotherm was found to be 59.9 and 45.5mgg-1 for As(III) and As(V) respectively at pH 7.0. Although the presence of competing anions like SO42-, HCO3- and NO3- did not show pronounced effect, PO43- had an inhibitory action on the adsorption. The XPS analyses of As-reacted Mt-nZVI indicated the occurrence of surface catalyzed oxidation of As(III) to As(V). The possible regeneration using 0.1M NaOH and performance of Mt-nZVI was investigated by repeating adsorption-elution process. This study has great significance for demonstrating Mt-nZVI as potential adsorbent to reduce elevated levels of As in groundwater

panish National Research Programme supported this work through Project CGL2010-22168-C03-03

© Chemical Engineering Journal, 2014, vol. 243, p. 14-23

Elsevier

Manager: Ministerio de Ciencia e Innovación (Espanya)
Author: Bhowmick, Subhamoy
Chakraborty, Sudipta
Mondal, Priyanka
Renterghem, Wouter van
Van Den Berghe, Sven‏
Roman-Ross, Gabriela
Chatterjee, Debashis
Iglesias Juncà, Mònica
Date: 2014 May 1
Abstract: Montmorillonite-supported nanoscale zero-valent iron (Mt-nZVI) has been synthesized to remove inorganic arsenic (As) from aqueous solutions. BET, SEM, EDX, XRD and XPS were used to characterize the clay-supported material which consists mainly of core shell Fe(0) structure with an outer oxide/hydroxide shell. The dispersion of nZVI onto montmorillonite was found to be increased with decreasing tendency to agglomerate into larger particles. Batch experiments revealed that adsorption kinetics followed pseudo-second order rate equation with high affinity towards both As(III) and As(V) over a wide pH range (4-8) which was decreased at pH>9. The maximum adsorption capacity calculated from the Langmuir adsorption isotherm was found to be 59.9 and 45.5mgg-1 for As(III) and As(V) respectively at pH 7.0. Although the presence of competing anions like SO42-, HCO3- and NO3- did not show pronounced effect, PO43- had an inhibitory action on the adsorption. The XPS analyses of As-reacted Mt-nZVI indicated the occurrence of surface catalyzed oxidation of As(III) to As(V). The possible regeneration using 0.1M NaOH and performance of Mt-nZVI was investigated by repeating adsorption-elution process. This study has great significance for demonstrating Mt-nZVI as potential adsorbent to reduce elevated levels of As in groundwater
panish National Research Programme supported this work through Project CGL2010-22168-C03-03
Format: application/pdf
Citation: 023353
ISSN: 1385-8947
Document access: http://hdl.handle.net/10256/11950
Language: eng
Publisher: Elsevier
Collection: MICINN/PN 2011-2013/CGL2010-22168-C03-0
Reproducció digital del document publicat a: http://dx.doi.org/10.1016/j.cej.2013.12.049
Articles publicats (D-Q)
Is part of: © Chemical Engineering Journal, 2014, vol. 243, p. 14-23
Rights: Tots els drets reservats
Subject: Aigües subterrànies -- Depuració
Groundwater -- Purification
Arsènic
Arsenic
Aigües subterrànies -- Contaminació
Groundwater -- Pollution
Title: Montmorillonite-supported nanoscale zero-valent iron for removal of arsenic from aqueous solution: Kinetics and mechanism
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

Subjects

Authors