Geophysics for urban mining and the first surveys in Denmark: rationale, field activity and preliminary results

Abstract

<jats:p>Geophysical methods have been widely used in recent decades to investigate and monitor landfill sites for environmental purposes. With the advent of the circular economy, waste contained in old landfills may be considered a resource that can be developed. Since the content of old landfills is largely unknown, the occurrence and quantity of valuable materials must be investigated before embarking on any development activity. Two landfills on Sjælland, Denmark (located at Hvalsø and Avedøre) were selected for a pilot study to characterise their content. At both locations, a set of geophysical surveys is underway. Here, we present the data obtained from magnetic and 2D seismic refraction surveys. Magnetic data show various anomalies that can be interpreted as caused by iron-rich waste. At both sites, the landfill material results in generally low P-wave velocity (&lt;400 m/s), lower than those obtained for Quaternary sediments at Avedøre. The seismic velocities appear to increase in the presence of metals or by compaction with depth (&gt;550 m/s). We propose that seismic refraction can thus define the bottom of the landfill and possibly its internal structure, especially when combined with other methods.</jats:p>

The EU Training Network for Resource Recovery through Enhanced Landfill Mining—A Review

“…In summary, NEW-MINE results confirm that ELFM is ecologically favorable, but economically not profitable, which demonstrates the need for an integrated ecological and economic assessment [9,35]. This means, that for those cases in which this integrated assessment shows a positive effect of ELFM, economic incentives would be required to make secondary raw materials or recycled products from ELFM competitive in the market.…”

“…It was found that 80% of these scenarios show negative results and that revenues from avoided landfill management costs are more important than revenues from resource recovery [165]. This study was cited in a review paper on the impact of landfills on the environment [166] in a study on the environmental and economic assessment of ELFM in Tehran [167] and with respect to geophysical exploration of landfills [35].…”

“…The differences between the bulk susceptibility derived from inverse modelling of the field data (0.06 to 0.11 SI) and the values obtained from computing from the values from the reference materials (0.01 to 0.05 SI) highlight the challenges to determine the iron content in landfills from magnetic data. This publication has not yet been cited, although two publications released in 2020 have addressed magnetic exploration in the context of landfill mining [34,35].…”

“…With respect to the number of publications citing the NEW-MINE publications, no significant difference between disciplinary and interdisciplinary publications is visible. Although most disciplinary publications were cited by researchers from other disciplines (e.g., [165] by [35]), most of them were cited by colleagues from the authors' discipline.…”

Anthropogenic Geology and the Role of Public Sector Organisations

“…To characterize anthropogenic resources from artificial ground there is a need to develop the AG discipline with knowledge tools and methods. This includes the ability to develop and correctly assess the results from geophysical methods (e.g., Sandrin et al, 2020;Jonsson et al, 2023), geochemistry (Jonsson et al, 2023) and new sedimentary settings (Dijkstra et al, 2019) of such deposits.…”