Author(s): M. T. Rahman; A. Mano; K. Udo; Y. Ishibashi
Linked Author(s):
Keywords: Bsorption; Sandy aquifer; Adsorbent; Hydrous oxide minerals andspectroscopic study
Abstract: Elevated Arsenic (As) in the groundwater may essentially be limited by sorption with the natural aquifer materials containing considerable amount of hydrous iron oxides. This paper explores the potentiality of As sorption by the natural aquifer materials in the upper shallow sandy aquifers in the South-Western Bangladesh. Sorption potentiality of the natural aquifer sediment was found very promising in attenuating dissolved As from the contaminated groundwater (GW). Particularly, finer particle containing larger Iron oxyhydroxides may have much better adsorption capability (92%) than that having medium grains with relatively lower iron minerals. Spectroscopic study such as bulk mineralogical analysis by XRD, elemental analysis by XRF, and elemental mapping by SEM and TEM further strongly support the wide-spread presence of the adsorbent minerals like iron oxy-hydroxide in the aquifer sediments. Partition coefficient, Kd and reaction rate Kr obtained from the laboratory adsorption experiment were utilized as the key input parameters for the numerical code TRANSQ-1D. Numerical analysis shows that after 20 years significant dissolved As from GW would be removed by the natural absorption onto the oxidized sediments.
Year: 2009