DYNAMIC STUDIES ON SORPTION CHARACTERISTICS OF RA-226 ON MANGANESE-DIOXIDE

Characteristics of Ra-226 sorption on MnO2 were investigated by dynamic tests using different types of water under various conditions, such as Ra-226 activity, pH, chemical species and contact time. Tests indicate that sorption varies with different column geometries and contact times. Sorption values of 23% to 92% were obtained with 10.00g of MnO2 at flow rates of 1100mL min(-1) to 16mL mid(-1) respectively, using column heights of 16mm to 65mm and internal diameters of 19.0mm to 9.25mm respectively. The sorption amount showed no dependence on Ra-226 activity (upto 1000Bq), types of water (distilled, tap and simulated groundwater) and pH when this exceeds 3.6 (pK at zero point charge of MnO2 is 5.5). An enthalpy change value of 20.0 kJ mol(-1) was obtained indicating a chemical and/or specific sorption mechanism(s).