Testing the possibility for reusing mswi bottom ash in Greenlandic road construction

Gunvor Marie Kirkelund, Anders Stuhr Jørgensen, Arne Villumsen

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Abstract

In Greenland waste has traditionally been dumped at open disposal sites combined with uncontrolled incineration. In the mid 1990’ties the first waste strategy was implemented in Greenland. As a result simple and small municipal solid waste incineration (MSWI) plants were implemented in towns and settlements primarily to minimize the amount of waste at the disposal sites. In Greenland the household waste is generally sorted into four fractions [1]: combustible, metal, hazardous waste and mixed waste and there are problems of sorting the metal and hazardous waste properly from the combustible waste, which can influence the quality of MWSI residues. About 15,000 tons MSWI bottom ash is produced annually in Greenland and is disposed of at the open disposal sites without leachate collection or
encapsulation. The MSWI bottom ash could have value as a secondary resource in construction work in Greenland. This would contribute to solve the problem of disposal and possible related environmental problems in the vulnerable Greenlandic environment.
In this study, MSWI bottom ash was collected from the disposal site in the town of Sisimiut in Western Greenland and characterized and tested for technical requirements (a grain size distribution, wear resistance, visual fraction analysis and bearing capacity) for reuse as fill material in road construction [2]. Environmental classification based on heavy metal content and leachability was also investigated.
The tests showed that it will not be possible to use the bottom ash directly after the incineration as the bottom ash did not comply with all the requirements specified by the Danish Road Directorate. These technical requirements could be improved by removing large fractions (> 45mm) and metal parts as well as changing the grain size distribution in the smaller fractions (< 0.5 mm). The bearing capacity showed a CBR-value of 21.4%, which is acceptable for the intended use. The heavy metal content and leachable amount of heavy metals in the bottom ash were under the Danish guideline levels for reuse of contaminated waste for geotechnical purposes as filler in roads [3]. Thus, pretreatment or better sorting of the waste before incineration is necessary to improve the quality of the bottom ash before reuse as road fill is possible.
References
[1] Eisted, R., Christensen, T.H.: Waste management in Greenland: Current situation and challenges. Waste Manage. Res. DOI: 10.1177/0734242X10395421 (2011)
[2] The Danish Road Directorate: Bundsikring af forbrændingsslagge – efter europæiske standarder. Rapport 133 (in Danish) (2004)
[3] Danish Ministry of the Environment: Bekendtgørelsen om genanvendelse af restprodukter og jord til bygge og anlægsarbejder BEK nr. 1480 af 12/12/2007 (in Danish) (2007)
Original languageEnglish
Title of host publicationThe 4th International Conference on Engineering for Waste and Biomass Valorisation (WasteEng12) : Book of abstracts
Number of pages1
Publication date2012
Pages207
ISBN (Print)979-10-91526-00-5
Publication statusPublished - 2012
Event4th International Conference on Engineering for Waste and Biomass Valorisation - Porto, Portugal
Duration: 10 Sep 201213 Sep 2012
Conference number: 4
http://www.wasteeng2012.org/

Conference

Conference4th International Conference on Engineering for Waste and Biomass Valorisation
Number4
CountryPortugal
CityPorto
Period10/09/201213/09/2012
Internet address

Cite this

Kirkelund, G. M., Jørgensen, A. S., & Villumsen, A. (2012). Testing the possibility for reusing mswi bottom ash in Greenlandic road construction. In The 4th International Conference on Engineering for Waste and Biomass Valorisation (WasteEng12): Book of abstracts (pp. 207)