Featured projects (1)
The need to minimize the amount and foster the safe treatment of waste, and thereby reduce the risk of contamination; emphasises the importance of promoting technologies which are environmentally sound with products suitable for re-use/recycling. This project establishes an experimental method to determine the performance of contaminant barriers built with natural clay and construction waste or biomass ash. The aim is to (1) evaluate the attenuation and containment capacities by these mixtures of contaminants in the long term, (2) develop design guidelines to construct barriers for waste facilities and similar applications, and (3) interpret their performance using numerical modelling tools. Landfill leachate and CO2 gas are passed through different waste:clay mixtures in a geotechnical centrifuge which simulates realistic times, pressures and temperatures of landfill field. The geochemistry of the pore water barriers after permeation are examined to deduce pollutant removal and retention processes. The exposure effects of these barriers to an aggressive acid, rainfall or groundwater are studied too. Results are aimed at recycling industrial residues and conserving natural resources (clay) by constructing contaminant barriers. It will also provide an effective and more environmentally sustainable basis to control landfill pollution risks. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 743880. This work reflects only the author’s view, exempting the community from any liability.
Featured research (2)
Soils in intensively farmed areas of the world are prone to degradation. Amendment of such soils with organic waste materials attempts to restore soil quality. Organic amendments are heterogeneous media, which are a source of soil organic matter (SOM) and maintain or restore chemical, physical, biological and ecological functionality. More specifically, an increase in SOM can influence the soil microclimate, microbial community structure, biomass turnover and mineralisation of nutrients. The search is on-going for locally sourced alternatives as many forms may be costly or geographically limiting. The present review focuses on a heterogeneous group of amendments i.e. biochar and brown coal waste (BCW). Both biochar (made from a variety of feedstocks at various temperatures) and BCW (mined extensively) are options that have worldwide applicability. These materials have very high C contents and soil stability, therefore can be used for long-term C sequestration to abate greenhouse gas emissions and as conditioners to improve soil quality. However, biochar is costly for large-scale applications and BCW may have inherently high moisture and pollutant contents. Future studies should focus on the long-term application of these amendments and determine the physicochemical properties of the soil, bioavailability of soil contaminants, diversity of soil communities and productivity of selected crops. Furthermore, the development of in situ technologies to lower production and processing costs of biochar and BCW would improve their economic feasibility for large-scale application.
In a world where circular economy and zero waste are taking over, exploring the potentialities to transform a residue into a marketable product is essential. Industrial process residues are very abundant in part due to the fourth industrial revolution currently evolving. The reuse of industrial residues would save natural resources, avoid the cost of landfill permits, reduce land reclamation and provide economic benefits from their sale. Hence the importance of studying their feasibility for beneficial use (or recycling) with zero risk to human health. The potential risk is assessed by the leachability of contaminants (e.g., heavy metals) to ground water, fresh water or soils, above harmful concentrations. These contaminants (constituents released from the residues by dissolution/percolation with water) can accumulate in plants and pass into the food chain. Here, we compare different standard methods and discuss the differences in the risk estimation.
- Department of Civil and Structural Engineering
About Steven F Thornton
- Steve Thornton currently works at the Department of Civil and Structural Engineering, The University of Sheffield, UK, where he leads the Groundwater Protection and Restoration Group. He does multidisciplinary research in contaminant hydrogeology, hydrogeochemistry and geomicrobiology on the broad theme of contaminated soil and groundwater restoration in a wide range of contexts covering impacts from industrial and agricultural sources. Current projects include 'H2020 Marie Curie ITN INSPIRATION - managing soil and groundwater impacts from agriculture for sustainable intensification', 'Biodegradation of ETBE in groundwater' and 'Developing high attenuation barriers for waste disposal sites'.