No abstract

No abstract

Resource and environmental safety protocols of incineration residues were evaluated by analyzing the metal concentration, heavy metal elution, desalination behavior, and chlorine removal ratio owing to particle size differences between bottom ash (BA) and grate sifting deposition ash (GA). In the total content test, Cl, Zn, and Cr in the incinerator BA exceeded the cement acceptance standard (Cl: 1000 mg/kg; Zn: 1700 mg/kg, and Cr: 170 mg/kg) at almost all of the particle sizes, while Au, Ag, Pd, and Zn had high contents in the GA. When using BA as a construction material, heavy metal elution values and contents are restricted as per the product quality standards based on the Japanese soil pollution control law. Lead within the BA and GA exceeded the standard values for most particle sizes. We predicted that there would be a limit on the elution of K by only washing with water. The removal ratio of total chlorine by particle size was approximately 20–70%, where the effect of the particle size on the removal ratio was small, suggesting that the elution of chlorine was complete in approximately 6 hours. These results contribute to information on the recycling of BA and GA.

With the ratio of municipal solid waste incineration residue to final disposal sites amounting to 77 %, as of FY2008, it is crucial that resource recycling be systematically accelerated. For urban areas in particular, employment of ordinary Portland cement requiring dechlorination for large amounts of municipal solid incineration residue should be considered together with wide-area treatment that incorporates eco-cement requiring the use of up to 50 % or more incineration residue for cement raw material. Meanwhile, the use of existing cement factories must also be considered for utilization of molten slag, metal recovery by extraction or physical sorting according to regional characteristics. Presentation of an optimal public system that will be able to contribute to integrated efforts for the environment, the economy, and society as a whole is required.

No abstract