Sorption experiments of Cr(III) onto silica

The sorption and desorption behaviour of chromium( III) onto amorphous silicagel has been studied for two cases: freshly prepared and aged solutions. We have examined how solution pH, initial Cr(III) concentration, valency and concentration of background electrolyte and the presence of fluoride ion affect these processes. Desorption can be induced by acidification. Applying the same solution conditions, Cr(III) uptake and release are greater from aged solutions. Outer sphere complex formation can be deduced from the great ionic strength dependence at the onset of the sorption. (C) 1998 Elsevier Science B.V. All rights reserved.