Evaluation of the recycling potential in accordance with pretreatment efficiency for ash discharged from waste incineration facilities in Korea

Due to recent policy changes in South Korea, the amount of incineration ash(IA) is expected to increase due to additional installation of incineration facilities or increased operation of incineration facilities.

by Myung Kyu Choi, Jang-Hyun Kang, Young-Sam Yoon, Heung-Min Yoo, Hang Seok Choi

Abstract

Due to recent policy changes in South Korea, the amount of incineration ash(IA) is expected to increase due to additional installation of incineration facilities or increased operation of incineration facilities. Therefore, it is necessary to prepare measures for the stable recycling of increasing IA. In this study, a database on the contents of hazardous substances in the IA from domestic incineration facilities was constructed by collecting the measurement data on the IA discharged from 20 facilities out of 372 domestic incineration facilities in 2020, survey results for 39 facilities, and literature survey data. The recycling potential was then comprehensively assessed by applying the hazardous substance removal efficiency according to the pretreatment method. The research results showed that the elution reduction efficiency for chlorine and heavy metal components differed by IA pretreatment technology. For washing treatment, the efficiency was found to be 56.1% for cadmium, 37.6% for chromium, 66.6% for copper, 91.2% for lead, and 78.9% for chlorine. For chelating agent treatment, the efficiency was 86.8% for chromium, 79.4% for copper, 61.8% for arsenic, 79.7% for cadmium, 76.1% for lead, 64.7% for mercury, and 6.4% for chlorine. Finally, in the case of melting, the efficiency was 99.9% for chromium, 42.7% for copper, 50.0% for arsenic, 82.1% for cadmium, 89.8% for lead, 94.0% for mercury, and 99.6% for chlorine, resulting in the highest overall efficiency. Before the application of the pretreatment technologies, only 15% of bottom ash and 0.6% of fly ash satisfied the IA recycling standards. It was predicted, however, that the standards will be met by 72% of bottom ash and 1.4% of fly ash after washing treatment, by 18% of bottom ash and 1.4% of fly ash after chelating agent treatment, and by 85% of bottom ash and 38% of fly ash after melting. Since the contents of hazardous substances in IA do not significantly change even after the application of the pretreatment technologies, it is considered that most IA cannot be recycled as raw materials and cement substitutes for ceramic products. Finally, IA can be used for media-contact recycling by satisfying heavy metal content criteria for soil contamination concerned area 2 if it is mixed with approximately 78% of general soil on average.

Keywords: Environmental assessment, Incineration ash, Pretreatment, Waste recycling law

published: Korea Society of Waste Management, 11|2022
Keywords: Energy Recovery, Methods, Analyses, Data, Korea (Republic of)

Dr. Young-Sam Yoon
National Institute of Environmental Research, Ministry of Environment