Comparative ease of separation of mixtures of selected nuisance anions (nitrate, nitrite, sulfate, phosphate) using Octolig~®

摘要

Mixtures of sodium salts of nitrate, nitrite, sulfate, and phosphate were prepared in relative amounts present in atomic waste containers with a view to effect removal by chromatography over Octolig , commercially available material with polyethylenediamine moieties covalently attached to high-surface area silica gel. Separation was attempted using aqueous solutions and column chromatography with Octolig~®. It is presumed that this material is capable of removing the anions by means of encapsulation. Matrix effects were tested by varying the relative concentrations. Rates of elution were varied 5-fold without adverse effect. The order of selectivity was found to be phosphate>sulfate>nitrite>nitrate through experiments altering the volume and relative concentrations. Quantitative removal of all anions (375 ppm of each) could be achieved given reasonable volumes of Octolig~®. An effort at regeneration by altering the pH of the eluant indicated the stability of the encapsulated anions.