SORPTION OF ZN(II) ON MARINE-SEDIMENTS BY A SEQUENTIAL EXTRACTION RADIOTRACER TECHNIQUE

The sorption behavior of Zn(II) on the mineral fractions of a marine s ediment collected from Sagami Bay (Japan) was investigated using a seq uential extraction-radiotracer technique. The extractions used were: ( i) 1 M CH3COONH4; (ii) 4 x 10(-2) M NH(2)OHt . HCl/25% CH3COOH; (iii) 30% H2O2(pH 2); and (iv) 7 M HNO3. The residues remaining after the ch emical treatment were collected, and used for the sorption experiments with Zn-65(II) as a tracer. The sorption isotherms of Zn-65(II) on al l the fractions except for one with a strong acid treatment fitted a L angmuir type equation. The capacities of the individual mineral fracti ons for Zn-65(II) sorption were estimated from the isotherms. Treatmen t with 7 M HNO3 removed almost all the sorptive sites for Zn(II) ions.