A new two-step modification method has been proposed where 1.8% HCl and 3.1% HNO3 were applied to modify the interlayer of vermiculite (VMT). This product was given 90 °C of heat in 30% H2SO4 solution that was used for Pb (II) and Sb (III) adsorption. The EDTA presence on the individual adsorption was assessed. X-ray diffraction revealed that the VMT inter-stratified reflection through acid intercalation within the interlayer decreased the parallel gaps between the atoms, witnessing on the outer-sphere adsorption. The driving force was found electrostatic, which fits well with pseudo-second-order kinetics and Langmuir isotherm. The Pb (II) and Sb (III) uptake followed descending order adsorption with increasing concentration of chelating EDTA. Three consecutive desorption cycles revealed that the prepared adsorbent was suitable that may be regarded as a good candidate for complex wastewaters.
Keywords: Enhanced adsorption; Modified vermiculite; Pb (II)-EDTA; Sb (III)-EDTA; Two-step modification.
© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.