The effect of chemical composition on the PCT durability of mixed waste glasses from wastewater treatment sludges

The Mixed Waste Integrated Program (NMIP) at the Department of Energy (DOE) has taken a serious look at vitrification for treatment of low-level mixed waste streams. This was prompted, in part, by the fact that the EPA has declared that vitrification is the Best Demonstrated Available Technology for the disposal of high-level radioactive waste. Among the low-level mixed waste streams within the DOE complex, which are under consideration for vitrification, are wastewater treatment sludges at the Savannah River Site (SRS), Oak Ridge Reservation (ORR), Rocky Flats Plant (RFP), and Los Alamos National Laboratory (LANL), These sludges typically contain low levels of radioactive and hazardous metals, water, and additives from the waste treatment process itself The treatment additives normally include precipitating and flocculating agents such as sodium, calcium, magnesium, and iron compounds or siliceous filter aids from the dewatering process. These treatment additives tend to be soluble in silicate glass and are thus amenable to vitrification