The United States Department of Energy policy for management of mixed (radioactive and hazardous) waste is in the development stage. Regardless of the approach to treatment of mixed waste, significant preprocessing will be necessary. The separation requirements for preprocessing of mixed waste will vary greatly depending on the downstream treatment requirements, the contents of the mixed waste stream, and the regulatory requirements at the waste treatment site. During the past year, the Department of Energy’s Mixed Waste Integrated Program (MWIP) has begun to identify separation requirements, applicable commercial technologies, and emerging technologies that may meet specific requirements. The current emphasis on developing emerging separation technologies for the MWIP include : freeze crystallization for gross separation of dissolved solids and organics from an aqueous waste stream; a bio-catalytic process for nitrate destruction; the General Electric KI/I-2 process for separating mercury from noncombustible solids and aqueous sludges; and the 3M/IBC membrane technology for separating mercury, cesium and strontium from aqueous streams.