Thermal destruction of wastes containing polychlorinated naphthalenes in an industrial waste incinerator

摘要

A series of verification tests were carried out in order to confirm that polychlorinated naphthalenes (PCNs) contained in synthetic rubber products (Neoprene FB products) and aerosol adhesives, which were accidentally imported into Japan, could be thermally destroyed using an industrial waste incinerator. In the verification tests, Neoprene FB products containing PCNs at a concentration of 2800mg/kg were added to industrial wastes at a ratio of 600mg Neoprene FB product/kg-waste, and then incinerated at an average temperature of 985 degrees C. Total PCN concentrations were 14ng/m(3)N in stack gas, 5.7ng/g in bottom ash, 0.98ng/g in boiler dust, and 1.2ng/g in fly ash. Destruction efficiency (DE) and destruction removal efficiency (DRE) of congener No. 38/40, which is considered an input marker congener, were 99.9974 and 99.9995%, respectively. The following dioxin concentrations were found: 0.11ng-TEQ/m(3)N for the stack gas, 0.096ng-TEQ/g for the bottom ash, 0.010ng-TEQ/g for the boiler dust, and 0.072ng-TEQ/g for the fly ash. Since the PCN levels in the PCN destruction test were even at slightly lower concentrations than in the baseline test without PCN addition, the detected PCNs are to a large degree unintentionally produced PCNs and does not mainly stem from input material. Also, the dioxin levels did not change. From these results, we confirmed that PCNs contained in Neoprene FB products and aerosol adhesives could be destroyed to a high degree by high-temperature incineration. Therefore, all recalled Neoprene FB products and aerosol adhesives containing PCNs were successfully treated under the same conditions as the verification tests.