State-of-the-art treatment processes for municipal solid waste incineration residues in Japan

Abstract

Solid residues from municipal solid waste incineration (MSWI) can be categorized as air pollution control residues (AR) and bottom ash (BA). Both categories pose a particular environmental threat on account of the risk of the release of dioxins and metals. In Japan, handling of MSWI residues is of major concern and the treatment of AR prior to landfilling is stipulated. Accepted treatment techniques are melting, cementitious S/S (stabilization and solidification), stabilization with a chemical agent and acid extraction. These methods are reviewed and evaluated in this paper with respect to: quality; quantity and utilization of end products; treatment costs; energy demand and process reliability. Thermal processes are superior regarding dioxin removal as well as material recovery and reuse, but treatment costs can be as high as 60 000 ¥ t -1 , i.e. one order of magnitude higher than for other processes. Cementitious S/S and chemical stabilization are characterized by the ease of operation, but the solid waste mass is increased by up to 40 and 10 wt.-%, respectively. Acid extraction is a proven and reliable technique and is inexpensive: nevertheless, it has the smallest share of the market.

Characteristics and application potential of municipal solid waste incineration (MSWI) bottom ashes from two waste-to-energy plants

“…It is also known that the properties of the MSWI bottom ashes from different plants and countries vary due to the source of solid waste and incineration process [32,33]. Moreover, the environmental legislation, management and application of the MSWI bottom ashes differ from country to country in consideration of the local situation [34,35].…”

Enrichment of elements in industrial waste incineration bottom ashes obtained from three different types of incinerators, as studied by ICP-AES and ICP-MS

“…The MIF values are calculated as the ratios of annual human use of the elements to their crustal reserves defined as Eq. 2 by Reimann and de Caritat: 14 (2) The total tonnages of elements mined annually and those reserved in the upper 2 km of the earth's crust were calculated from the data in the literature. 12,15,16 For example, 2.6 ϫ 10 6 t of Pb is mined in the world annually, and 1.5 ϫ 10 13 t of it is contained in the upper 2 km of the crust.…”

“…Approximately 80%-90% of incineration product is bottom ash. 1,2 Waste incineration ashes are dumped in landfill sites, either directly or after treatment. Sustainable resource management and environmental conservation have become important considerations in solid waste management strategies.…”

Pre-treatment of municipal solid waste incineration (MSWI) bottom ash for utilisation in cement mortar

“…Therefore, prior treatment before their landfilling and recycling is necessary [1,[4][5][6][7][8]. Now-a-days, several techniques such as cement based solidification/stabilization, melting, stabilization using some chemical compounds and extractions of toxic components using some reagents are applied to treat various types of MSWI ash [9].…”