Removal of arsenate from contaminated water by Granular Activated Carbon embedded with nano scale zero-valent iron

Rashadul Islam Chowdhury, Catherine N. Mulligan

In the proceedings of: GeoMontréal 2013: 66th Canadian Geotechnical Conference; 11th joint with IAH-CNC

Session: Groundwater Quality

ABSTRACT: This study investigated the removal of arsenate from groundwater by Granular Activated Carbon (GAC) supported nano scale zero-valent iron (nZVI). GAC supported nZVI (nZVI/GAC) composite was synthesized by hydrolyzing Fe(III) salt on GAC, reduced by NaBH4 and dried under vacuum . Synthesized nZVI/GAC was characterized using scanning electron microscopy (SEM) along with EDS, and X-ray diffraction (XRD). The adsorption depends on pH, initial concentration, and reaction time. Acidic pH (2~6.5) had an insignificant effect on adsorption. Among competitive ions, phosphate and silicate affected the most while sulfate, nitrate, chloride, fluoride, manganese, magnesium and calcium had insignificant impact. The experimental data were evaluated with Langmuir and Freundlich isotherms The reaction kinetics followed the pseudo-second order model. The results indicated that nZVI/GAC is a promising adsorbent for arsenic removal.

RÉSUMÉ: Cette étude a été effectuée sur la suppression de l'arséniate de la nappe phréatique par le charbon actif en grains (CAG) soutenu nano échelle fer zéro-valent (nZVI). Une composite du GAC avec nZVI (nZVI / GAC) a été synthétisée par l™hydrolyse de Fe (III) de sel sur GAC, réduit par NaBH4 et séché dans un état de vide. Le nZVI / GAC synthétisé a été caractérisée par microscopie électronique à balayage (MEB) avec EDS, et la diffraction des rayons X (XRD). L'adsorption dépend du pH, de la concentration initiale, et du temps de réaction. Le pH acide (2 ~ 6.5) a eu un effet négligeable sur l'adsorption. Parmi les ions compétitifs, le phosphate et le silicate ont affecté le plus alors que le sulfate, le nitrate, le chlorure, le fluorure, le manganèse, le magnésium et le calcium ont eu un impact insignifiant. Les deux isothermes de Langmuir et Freundlich représentaient les données expérimentales. La cinétique de réaction suivie de la pseudo-deuxième modèle de commande. Les résultats indiquent que nZVI / GAC est un adsorbant prometteuse pour l'élimination de l'arsenic.

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Cite this article:
Rashadul Islam Chowdhury; Catherine N. Mulligan (2013) Removal of arsenate from contaminated water by Granular Activated Carbon embedded with nano scale zero-valent iron in GEO2013. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GeoMon2013Paper300,author = Rashadul Islam Chowdhury; Catherine N. Mulligan,title = Removal of arsenate from contaminated water by Granular Activated Carbon embedded with nano scale zero-valent iron,year = 2013}