Novel hybrid materials in the remediation of ground waters contaminated with As(III) and As(V)

Natural mica type of clay mineral sericite was modified to obtain the materials viz., Al-HDTMA-sericite (AH) and Al-AMBA-sericite (AA) which was characterized by the FT-IR and XRD data and morphologically analyzed by the SEM images. Further, the simulated batch reactor data indicated that increase in sorptive concentration enhanced the uptake of these pollutants and the 1000 times increase in ionic strength i.e., background electrolyte concentration (NaNO3) caused an insignificant decrease in As(V) removal, which inferred that As(V) was adsorbed specifically onto the solid surface. However, it was affected greatly with As(III) pointed that As(III) was sorbed mainly through electrostatic or even with van der Waals attraction. pH dependence data showed that arsenic removal was greatly affected with change in solution pH. Simultaneous presence of phenol in the removal of As(III) or As(V) showed insignificant change in arsenic removal by these materials pointed that different sorption sites available for these two different contaminants. Results obtained under dynamic conditions inferred that materials were reasonably useful in the speciation/attenuation of these two metal ions from water bodies. The breakthrough data was fitted well to the Thomas equation and hence, the maximum amount of the As(III) or As(V) to be loaded was found to be 0.338 and 0.433 mg/g respectively for AA and AH for As(III) and 0.541 and 0.852 mg/g respectively for AA and AH for As(V) under the specified column reactor conditions. Comparing these two materials AH possessed with higher removal capacity than AA, at least, for these two contaminants. (C) 2012 Elsevier B.V. All rights reserved.