Study on an advanced treatment system for medical waste drainage containing radioactive iodine (II). In-place test using drainage in a medical facility

Recently, 131I has become to be used for treatment by the increment of its dose. Treatment doses for thyroid cancer amount to GBq order. The regulations with regard to the discharge of the waste drainage containing 131I are very strict, and it burdens the drainage treatment facilities. When usage of 131I for treatment becomes popular, the drainage treatment facilities may groan under the heavy burden. We made an equipment with activated carbon impregnated with per-bromine ion which efficiently adsorbs 131I in drainage by halogen substitution reaction and tested it at the drainage facility in a hospital. The removal efficiency of 131I was more than 99% using only a single impregnated carbon column (diameter 100 mm, length 220 mm) under 4 L/min flow rate. For a practical application, it will be important to improve the performance and the ability for a long term use. (author)