Sorptive Removal of Technetium from Alkaline Heavy Metals Sludge Filtrate Containing Nitrate Ion

摘要

A so-called ''raffinate'' waste stream is generated from various uranium recovery and equipment cleaning and decontamination activities at the X-705 facility of the Portsmouth (Ohio) Gaseous Diffusion Plant (PORTS). The composition of this waste stream is generally characterized by high concentrations of nitric acid, toxic heavy metals, and low level of radioactive nuclides ((sup 235)U,(sup 99)Tc). We have found that cross-linked poly-4-vinyl-pyridine (PVP) resin (such as Reillex 402) is more efficient than strongly basic anion exchange resin for removed of Tc in wastes containing high concentrations of nitrate ion, resin loading by nitrate is greatly reduced, and PVP resins are very stable with respect to chemical and radiological degradation. Also the inexpensive inorganic reagents, elemental iron (degreased iron filings, about 40 mesh) and ferrous sulfide (in particular Greigite (Fe(sub 3)S(sub 4))) are very efficient for the removal of Tc and also soluble mercury from aqueous nitrate wastes. 2 refs., 1 fig., 4 tabs. (ERA citation 13:049171)