title: Field-scale study of the influence of differing remediation strategies on trace metal geochemistry in metal mine tailings from the Irish Midlands.
abstract: Mine tailings represent a globally significant source of potentially harmful elements (PHEs) to the environment. The management of large volumes of mine tailings represents a major challenge to the mining industry and environmental managers. This field-scale study evaluates the impact of two highly contrasting remediation approaches to the management and stabilisation of mine tailings. The geochemistry of the tailings, overlying amendment layers and vegetation are examined in the light of the different management approaches. Pseudo-total As, Cd and Pb concentrations and solid-state partitioning (speciation), determined via sequential extraction, were established for two Tailings Management Facilities (TMFs) in Ireland subjected to the following: (1) a 'walk-away' approach (Silvermines) and (2) application of an amendment layer (Galmoy). PHE concentrations in roots and herbage of grasses growing on the TMFs were also determined. Results identify very different PHE concentration profiles with depth through the TMFs and the impact of remediation approach on concentrations and their potential bioavailability in the rooting zone of grass species. Data also highlight the importance of choice of grass species in remediation approaches and the benefits of relatively shallow-rooting Agrostis capillaris and Festuca rubra varieties. In addition, data from the Galmoy TMF indicate the importance of regional soil geochemistry for interpreting the influence of the PHE geochemistry of capping and amendment layers applied to mine tailings.
authors.affiliation: Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, Ceredigion, SY23 3DB, UK.
authors.forename: William T
authors.initials: WT
authors.lastname: Perkins
authors.affiliation: School of Environment, Natural Resources and Geography, Bangor University, Bangor, Gwynedd, LL57 2UW, UK. g.bird@bangor.ac.uk.
authors.forename: Graham
authors.initials: G
authors.lastname: Bird
authors.affiliation: Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Kreuzeckbahnstraße 19, 82467, Garmisch-Partenkirchen, Germany.
authors.forename: Suzanne R
authors.initials: SR
authors.lastname: Jacobs
authors.affiliation: Lundin Mining UK Ltd, Hayworthe House, Haywards Heath, West Sussex, RH16 1DB, UK.
authors.forename: Cora
authors.initials: C
authors.lastname: Devoy
mesh_terms: D052918:Environmental Restoration and Remediation; D031751:Festuca / Q000378:metabolism; D007494:Ireland; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry*; D008906:Mining; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D014131:Trace Elements
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements
keywords: Metals; Mine tailings; Phytoremediation; Plant uptake; Speciation