Abstract: The method of the invention provides a geopolymeric binder in powder, used for the ultra rapid treatment of materials, soils or mining tailings, containing toxic wastes. Said geopolymeric binder has a setting time equal to or greater than 30 minutes at a temperature of 20.degree. C. and a hardening rate such as to provide compression strengths (Sc) equal to or greater than 15 MPa, after only 4 hours at 20.degree. C., when tested in accordance with the standards applied to hydraulic binder mortars having a binder/sand ratio equal to 0.38 and a water/binder ratio between 0.22 and 0.27. The preparation method includes the following three reactive constituents:a) an alumino-silicate oxide (Si.sub.2 O.sub.5, Al.sub.2 O.sub.2) in which the Al cation is in (IV-V) coordination as determined by MAS-NMR analytical spectroscopy for .sup.27 Al;b) a disilicate of sodium and/or potassium (Na.sub.2.K.sub.2)(H.sub.3 SiO.sub.4).sub.

Abstract: The present invention relates to a process for nuclear waste disposal. In it, a glass forming mixture including an aqueous solution of one or more metal alkoxides, alcohol, and solubilized, low level radioactive waste having a pH effective to hydrolyze the one or more metal alkoxides is formed. The one or more metal alkoxides in the glass forming mixture are converted to a network of corresponding one or more metal oxides. A gel is then formed from the glass forming mixture containing the network of one or more metal oxides. The gel is dried and sintered under conditions effective to form a densified glass.

Abstract: In a method of treating a surface 12 of an object 10 contaminated with radionuclides 14, a laser source 16 is directed at the surface 12 to apply a local area 18 of intense heat to the surface 12. The laser source 16 is arranged to pass in a raster manner to cause local melting of the surface 12, surface 12 subsequently solidifying and fixing the radionuclides 14 therein. At least one layer of a coating material be applied before or after the application of the intense heat to fix and seal the radionuclides on or in the object.

Abstract: Remediation of soil, concrete and groundwater using electropotential gradient induced migration of a target ion and immobilization and/or confinement of the target ion by a host receptor matrix (HRM). In addition to immobilizing and/or confining the target ion, the HRM can comprise a buffer or an ionizable species which releases an exchange ion during application of the electropotential gradient. The exchange ion, when less mobile than a (H.sup.+) ion or hydroxyl (OH.sup.-) ion, increases the efficiency of energy usage during decontamination. The exchange ion can also perform other tasks in the vicinity of the electrodes which improve the decontamination process. The host receptor matrix can comprise a material which is water impermeable and which has a low surface energy, such as a layer of polytetrafluoroethylene film. When such a material is used, the host receptor matrix can comprise a receptacle in which there is a liquid and/or solid composition.