Ion exchange resins contaminated with a radioactive component are treated by exposing the contaminated ion exchange resins to a bound radio frequency electric field for uniformly heating them to drive off water. The dried ion exchange resins are then uniformly heated by a transversely uniform bound radio frequency electric field to a second higher temperature which chemically inactivates the functional groups of the ion exchange resins to destroy their hydrophilic property and convert them to a stabilized product for long-term safe storage.
This application is continuation-in-part of application Ser. No. 08/454,0900 filed May 30, 1995 now abandoned, which is a continuation-in-part of application Ser. No. 08/096,361 filed Jul. 22, 1993 now abandoned, which is a continuation-in-part of application Ser. No. 07/952,205 filed Sept. 28, 1992 now abandoned, which is a continuation-in-part of application Ser. No. 07/502,288 filed Mar. 30, 1990, now abandoned.
The invention discloses a microwave off-gas system in which microwave energy is used to treat gaseous waste. A treatment chamber is used to remediate off-gases from an emission source by passing the off-gases through a susceptor matrix, the matrix being exposed to microwave radiation. The microwave radiation and elevated temperatures within the combustion chamber provide for significant reductions in the qualitative and quantitative emissions of the gas waste stream.
The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.
