The treatment conditions of alkaline flocculation for acidic plutonium liquid wastes was studied, using ferric hydroxide and calcium phosphate as flocculants.
It was found that the decontamination factor DF for ferric hydroxide or calcium phosphate flocculation is about 103 when the plutonium concentration is 6.5×10-3μCi/ml under the treatment conditions of 500ppm flocculant concentration, pH 10-13 and 0.1M salt concentration. In order to obtain higher DF, repetition of treatment is proposed. It was observed that by one repetition of flocculation (ferric hydroxide-ferric hydroxide and ferric hydroxide-calcium phosphate), the DF is enhanced up to 105 or more when the plutonium concentration is 1.6μCi/ml under the treatment conditions described above.
The above results should be useful in planning the treatment process for acidic plutonium liquid wastes by alkaline flocculation.