Electron beam irradiated sheep wool – Prospective sorbent for heavy metals in wastewater

Abstract

Sheep wool water-washed in ultrasonic bath and slightly pre-dried was irradiated by accelerated electron beam applying dose of (0–350) kGy. The samples underwent sorption examination with Cr(III), Cd(II) and Pb(II). Sorption of Cr(III) by the irradiated wool investigated at unified concentration of 24 mmol dm−3 for each absorbed dose showed intensive increase of Cr(III) sorption up to 3.13 × against the non-irradiated sample. It is concluded that some residual humidity in irradiated wool, being a rich oxygen source, enhances sorption due to faster cysteic acid formation. Sorption experiments with Cr(III), Cd(II) and Pb(II) ions of lower concentration up to 1.4 mmol dm−3 individually indicated equal sorption as for non-irradiated wool up to 0.4 mmol dm−3. Beyond this concentration the sorption for the non-irradiated wool was lower compared with irradiated wool for any dose. The sorption increase depending on dose was different for particular doses. The order of the sorption in mg ion/1 g wool is in conformity with published data and correlates with size of the ionic radii (Pb(II) > Cd(II) > Cr(III)).