Kenzo Nishimaki

Feasibility study of the applicability of the activated sludge process to treatment of radioactive organic liquid waste

The authors used an activated sludge process to treat radioactive organic liquid waste. Organic liquid waste is difficult to treat by conventional radioactive liquid treatment processes, but in order to reduce long-term irradiation of the public the removal of radionuclides from such waste is preferable to dilution. Activated sludge processes are widely used for the biological treatment of sewage and are considered appropriate means for treating radioactive organic liquid waste. In this process, the fate of radionuclides eluted by treated water or immobilized by activated sludge, is extremely important for public safety and for the treatment of radioactive organic liquid waste. The authors performed uptake and desorption behavior experiments on the three short half-life radionuclides {sup 134}Cs, {sup 57}Co and {sup 85}Sr, and used three nutritive types of artificial sewage as the feed solution. On the basis of the results, they discuss the uptake-desorption behavior of these radionuclides in an activated sludge process. The authors conclude that treatment of radioactive organic liquid waste by an activated sludge process is possible, but improvements must be made in the process if it is to be more effective.