DEVELOPMENT OF TREATMENT SYSTEM FOR LAUNDRY WASTE WATERUSING ACCELERATED OZONATION PROCESS

摘要

An accelerated oxidation process to decompose organic materials using ozone gasrn(ozonation process) has been developed as an alternative treatment, with limited secondaryrnwaste generation, of hot laundry wastewater from nuclear power plants. In this ozonationrnsystem, high concentration ozone gas is mixed in the wastewater using an ejector and staticrnmixer in the circulation line connected to the wastewater collection tank. After thernconcentration of organic compounds decreases below the required value (one tenth of therninitial concentration), residual solid materials are separated by the normal filtration process. Arnpilot plant test, with a maximum capacity of 300 liters per batch, was performed usingrnsimulated laundry wastewater. The decomposition rate of organic compounds by thernozonation process depended mainly on the ozone supply rate and the wastewater temperature.rnThe concentration of total organic carbon could be reduced below the required value with onlyrnthe ozone injection. Since most of the organic solid materials could be decomposed byrnozone too, the specific resistance of wastewater, when passed through a membrane filter,rndecreased about two orders of magnitude with the ozonation process. The only secondaryrnradioactive waste generated from this ozonation process would be filter sludge, so the amountrnof radioactive waste would be reduced substantially.