A bench-scale study of a one-step dissolution process for treating contaminated fiberglass filters

High efficiency mist eliminators (HEME) and high efficiency particulate air filters will be used to remove particulate matter from offgases generated during melter feed preparation and vitrification of high-level radioactive waste at the Savannah River Site Defense Waste Processing Facility. The fiberglass filters will be contaminated with high-level, radioactive species and high-boiling organic compounds. This paper presents preliminary work on the one-step caustic dissolution process developed to dissolve the spent filters. Six experiments were performed on an organically fouled HEME sample using the one-step process. Consistent experimental trends indicated that silicon and aluminum were continuously leached from the sample upon reacting with sodium hydroxide, and formed soluble compounds. Calcium and magnesium reacted with the sodium hydroxide to form insoluble compounds in a semi-rigid matrix. The matrix fell apart easily in some experiments; in others, it required more rigorous agitation or a dispersing agent. Preliminary results also showed the effects of fouling, filter packing density, air sparging versus rotating basket agitation for mixing, and adding Triton X-405 as a dispersing agent