AN IMPROVED PHOSPHATE-FERROCYANIDE/VERMICULITE TREATMENT FOR HARWELL MEDIUM LEVEL EFFLUENT

摘要

Investigations have been carried out into the poor decontamination by vermiculite of certain Harwell radioactive effluents after treatment by a combined calcium-phosphate-copper ferrocyanide precipitation. Results indicated that poor performance only occurred when treating effluents from the Decontamination Centre, which contain a high concentration of phosphate ion and have a low pH value. It has been shown that by using zinc ferro¬cyanide instead of the copper salt for the chemical precipitation, there is a considerable improvement in the vermiculite stage decontamination without any adverse effect on the efficiency of the chemical treatment.