RETENTION OF TUNGSTEN(VI) BY 3 FINNISH MINERAL SOILS

Retention of W(VI) by three Finnish mineral soils from 10(-4) M soluti ons for 72 h was studied at pH 2.8-7.5, using an adsorbent:solution ra tio 1:100 (w:v) and 0.02 M KCl as a support medium. Retention was grea test from the most acidic samples, and at pH 3, 75-87% of the added W was retained. The W adsorption curves obtained for these mineral soils had different shapes compared with those reported for activated carbo n, ferric oxide and kaolin. Retention of W by soils was strong, and on ly a small amount of the retained W was desorbed during a 17 h treatme nt with 0.02 M KCl.