title: Alleviation of environmental risks associated with severely contaminated mine tailings using amendments: Modeling of trace element speciation, solubility, and plant accumulation.
abstract: Tailings are considered one of the most relevant sources of contamination associated with mining activities. Phytostabilization of mine spoils may need the application of the adequate combination of amendments to facilitate plant establishment and reduce their environmental impact. Two pot experiments were set up to assess the capability of 2 inorganic materials (calcium carbonate and a red mud derivate, ViroBindTM), alone or in combination with organic amendments, for the stabilization of highly acidic trace element-contaminated mine tailings using Atriplex halimus. The effects of the treatments on tailings and porewater physico-chemical properties and trace-element accumulation by the plants, as well as the processes governing trace elements speciation and solubility in soil solution and their bioavailability were modeled. The application of the amendments increased tailings pH and decreased (>99%) trace elements solubility in porewater, but also changed the speciation of soluble Cd, Cu, and Pb. All the treatments made A. halimus growth in the tailings possible; organic amendments increased plant biomass and nutritional status, and reduced trace-element accumulation in the plants. Tailings amendments modified trace-element speciation in porewater (favoring the formation of chlorides and/or organo-metallic forms) and their solubility and plant uptake, which were found to be mainly governed by tailing/porewater pH, electrical conductivity, and organic carbon content, as well as soluble/available trace-element concentrations. Environ Toxicol Chem 2016;35:2874-2884. © 2016 SETAC.
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, Campus Universitario de Espinardo (CEBAS-CSIC), Murcia, Spain. tpardo@iiag.csic.es.
authors.forename: Tania
authors.initials: T
authors.lastname: Pardo
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, Campus Universitario de Espinardo (CEBAS-CSIC), Murcia, Spain.
authors.forename: Cleménce
authors.initials: C
authors.lastname: Bes
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, Campus Universitario de Espinardo (CEBAS-CSIC), Murcia, Spain.
authors.forename: Maria Pilar
authors.initials: MP
authors.lastname: Bernal
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, Campus Universitario de Espinardo (CEBAS-CSIC), Murcia, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Clemente
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D002119:Calcium Carbonate / Q000737:chemistry; D008906:Mining; D008962:Models, Theoretical; D010944:Plants / Q000187:drug effects* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D012995:Solubility; D014131:Trace Elements / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements; D002119:Calcium Carbonate
keywords: Metal accumulation; Metal speciation; Phytostabilization; Soil contamination; Solubilization mechanisms