keywords AM(III) BATCH CM(III) EU(III) Eu IONIC-STRENGTH LASER-FLUORESCENCE SPECTROSCOPY MINERALS MX-80 bentonite Nuclear Science & Technology PH SMECTITE Science & Technology Sorption Sorption distribution coefficient TRLFS Technology Two-site protolysis nonelectrostatic surface complexation and cation exchange sorption model (2SPNE SC/CE model) pH and ionic strength dependences