In situ recovery of resources from waste repositories

The proposed research seeks to undertake scoping work with academia and industry to develop a new and exciting research field related to mining resources from landfill that seeks to address the following central question:

Can resources (materials of value e.g. metals, rare earth elements, plastics, energy) be recovered by leaching waste repositories whilst the material lies in situ, thus avoiding the need to actively mine the material?

The fundamental geoscience research question that underpins this is:

How can we understand and manipulate the in situ biogeochemistry of the waste within the repository to solubilise resources and recover them through leaching?

The concept and technology of in situ leaching has been developed in the mining industry for recovery of uranium and copper, and is done by circulating solutions to extract the elements and/or stimulating and enhancing microbial leaching. No-one has looked at the possibility of transfering this concept for application to recovery of resource from waste repositories. Wastes display diverse compositions, mineralogies, textures very different to that of ores and thus will require new science to understand and develop leaching methods to solubilise valuable components.

We will during the scoping stage be considering resource extraction the full range of wastes currently in UK landfills including industrial snd commercial waste (anticipated to be metal-rich), incinerator and fuel ash, mineral wastes, municipal waste and agricultural wastes to examine the idea of in situ leaching. We are particulary keen to identify during the grant which types of landfilled waste streams might be relatively enriched in certain resources and focus the full research proposal on recovery from these wastes. We envisage that in situ leaching could sidestep many of the problems that prevent realisation of the resource potential of former landfill sites, with important impacts not only in the UK but internationally. Furthermore, our aim is to not only investigate means to recover resource through in situ leaching but to also investigate how we can appropriately benchmark such processes (which we believe will have substantially lower environmental and human health impacts) in terms of life-cycle, human health and ecosystems service costs for comparison to retrieval of landfilled resources by 'conventional' dig-and-process landfill mining and against conventional mining of the same resources.

As anticipated in the call documents, there are no significant pathways to impact within the Catalyst Grant stage itself. However, we feel strongly that this research has real potential to actually kick-start a truly new discipline - in situ recovery of resources from waste repositories. As such we have envisaged some of the impacts that a full grant proposal in this area could achieve.

Based on the model of Impact defined by the RCUK, our work will contribute to both academic and societal impact. As a measure of our Academic Impact, we anticipate developing a new branch of technology - in situ recovery of resource from waste repositories and delivering and training highly skilled researchers. As a measure of our societal impact, we will i) contribute towards evidence based policy-making and influencing public policies and legislation at a local and regional level and ii) contribute towards resource recovery, environmental sustainability, protection and impact reduction. The anticipated outputs of our work, primarily the development of an understand of and the ability to manipulate the in situ biogeochemistry of waste within the repository to solubilise resources and recover them, have a range of potential beneficiaries including a wide range of industries, local and regional governments, professional institutions and academics.

1) Government (national and local level), Landfill operators, Waste management sector, Energy Sector (e.g. Anaerobic Digestion and combustion specialists), Waste recycling and recovery sector, Environmental Consultants and process/civil/environmental engineering firms:
The groups will benefit directly from the findings of the research through improved and/or new processes that may be developed through this research, they may also benefit from the early stages of information gathering in terms of quantifying the different resources in UK landfills. This latter point is also relevant for Government who will gain strategic benefit (e.g. security of supply data) from understanding resource currently in geological storage within UK landfill. Furthermore Governmental organisations will be able to advance their sustainability agendas toward achieving their sustainability target through reducing the need for virgin resources such as rare earth metal and improved energy harvesting from landfills. Other governmental organisations may benefit through the availability of robust information that can help inform the development of evidence-based policies.

2) Professional institutions:
This group of stakeholders will also benefit through their early involvement in the project and through its findings. They will be involved directly and indirectly in providing CPD training courses based on the findings of the research and the new and improved technologies that can result from it. This will ensure that their members are also able to benefit directly.

3) Academics interested in biogeochemistry of waste, resource recovery and environmental systems:
The development of an improved understanding of the in situ biogeochemistry of the waste within the repository and the ability to beneficially manipulate these conditions will be of interest to a wide range of academics.