SurfaceInteractions of Actinides with Alumina Colloids

ADSORPTION ONTO NATURAL COLLOIDS HAS BEEN SUGGESTED TO BE A MAJOR CONTROLLING PROCESS IN THE MOBILITY AND REMOVAL OF TRACE CONTAMINANTS IN NATURAL WATERS. THE DIFFERENT OXIDATION STATES AND HYDROLITIC BEHAVIOUR OF 5-F ELEMENTS INTRODUCED INTO THE ENVIRONMENT WITH THE NUCLEAR FUEL CYCLE OPERATIONS AND THE ATMOSPHERIC FALLOUT, MAKE SUCH PROCESSES PARTICULARLY COMPLEX. IN THIS STUDY RESULTS ARE GIVEN ON THE INFLUENCE OF PH, CARBONATE AND HUMIC SUBSTANCES CONCENTRATIONS ON THE ADSORPTION OF AM(III), TH(IV) AND NP(V) ONTO ALUMINA COLLOIDS AT FIXED IONIC STRENGTH. SURFACE INTERACTIONS HAVE BEEN FOUND TO BE OXIDATION STATE DEPENDENT, WITH ADSORPTION EDGES SHIFTING TOWARD HIGH PH IN THE ORDER TH(IV), AM(III), NP(V). CARBONATE IONS MARKEDLY REDUCE THE ADSORPTION OF NEPTUNIUM, AMERICIUM AND THORIUM AT RELATIVELY HIGH PH. THE ADDITION OF HUMIC SUBSTANCES INCREASES THE ACTINIDE UPTAKE AT LOW PH AND LOWERS THE ADSORPTION BY THE COLLOIDAL PARTICLES IN THE NEUTRAL TO ALKALINE PH RANGE

BIDOGLIO Giovanni;  RIGHETTO L.;  MARCANDALLI B.;  BELLOBONO I.R.; 

1995-03-15

JRC5477

https://publications.jrc.ec.europa.eu/repository/handle/JRC5477,