1. Environmental Technology Area, CTM-Centre Tecnològic, Av. Bases de Manresa 1, 08240 Manresa, Spain, Forschungszentrum Dresden-Rossendorf, Institute of Radiochemistry, P.O. Box 510119, 01314 Dresden, Germany, Chemical Engineering Department, Universitat Politècnica de Catalunya, 08028 barcelona, Spain, and AMPHOS 21 Consulting S.L. Passeig de Rubí, 29−31, 08197 Valldoreix, Spain