| 摘要 |
PURPOSE:To prevent the hydroxide of heavy metals from settling in a packed bed of a chelate resin when an aqueous soln. contg. heavy metals is passed through the packed bed by forming the individual resin grains constituting said bed into partially loaded type. CONSTITUTION:While a packed bed of a chelate resin is maintained in a fluid state, an acid or alkali soln. of an amt. at which the packed bed is put in a partially loaded state is brought in contact with this. As a method for this, there are a method of introducing a calculated amt. of an acid or alkali soln. to the upper part of the packed bed filled with water, then introducing gas such as air from the lower part and uniformly mixing the entire part, a method of introducing the soln. similar to the one mentioned above and a gas together from the lower part of the packed bed filled with water and allowing the same to contact with resin grains and a method of introducing a calculated amt. of a diluted acid or alkali soln. from the lower part of the packed bed at a speed higher than the fluidization speed of the resin, and allowing the same to contact with the resin grains while flowing the entire part. In treating the packed bed with the acid or alkali soln., the chelate resin may be of free type or loaded type. |
