Fates of radioactive arsenic, cesium, strontium and organo-chlorine during the gasification of mixed wastes in the presence of organic matter

Radioisotopes of arsenic, cesium, strontium and chlorine were mixed with organic matter to make mixed radioactive/hazardous wastes and gasified to destroy the organic fractions on a macroporous char matrix in a laboratory-scale version of cocurrent flow waste gasification. Except for chlorine, gasified as chlorobenzene on untreated char, essentially all the radionuclides were retained in the gasifier on the char residue. Complete retention of chlorine was obtained by treating the char with sodium hydroxide. Condensate from the gas product and char from a filter used to filter the gas can be recirculated through the system as additional assurance of zero release of radioactive substances. The spent char from the gasifier can be regasified with additional wastes, resulting in a concentration of radioactive substances onto char, which can eventually be converted to a nonleachable slag for ultimate disposal.