* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Reducing mobility of arsenic in a brownfield soil using stabilized
Survey
Document related concepts
Agroecology wikipedia , lookup
Human impact on the nitrogen cycle wikipedia , lookup
Soil erosion wikipedia , lookup
Plant nutrition wikipedia , lookup
Soil horizon wikipedia , lookup
Soil respiration wikipedia , lookup
Surface runoff wikipedia , lookup
Crop rotation wikipedia , lookup
Soil compaction (agriculture) wikipedia , lookup
Soil food web wikipedia , lookup
No-till farming wikipedia , lookup
Terra preta wikipedia , lookup
Soil salinity control wikipedia , lookup
Soil microbiology wikipedia , lookup
Transcript
Reducing mobility of arsenic in a brownfield soil using stabilized zero-valent iron nanoparticles M. Gil-Díaz1*, J. Alonso1, E. Rodríguez-Valdés2, M.C. Lobo1 1 IMIDRA, Finca “El Encín” A-2, Km 38,2. 28800 Alcalá de Henares (Madrid) Spain. 2 Universidad de Oviedo, Mieres 33600 (Asturias) Spain * Presenting author contact: [email protected] Arsenic is a trace element which is naturally found in the environment, but anthropogenic activities (e.g. mining, industrial wastes, application of agricultural pesticides, and military activities), have increased its concentration in soils and groundwater. It is one of the most toxic contaminants. Arsenic speciation in soils is complex, including organic forms and inorganic species, arsenate (As(V)) and arsenite (As(III)), which are the most abundant. The availability of As in soils is usually driven by many factors, such as pH, Fe-oxides, phosphorus, (co)precipitation in salts, organic matter, clays, rainfall, etc. In recent years, nanoscaled zero-valent iron (nZVI) has been tested to remediated both organic and inorganic pollutants in soil and groundwater, and has received increasing amounts of attention due to its potential for broader application, higher reactivity, and cost-effectiveness. Much of the research has been conducted with artificially contaminated soils. In the present study a highly As-contaminated soil from a brownfield was employed. The main objective of this research was to evaluate the effectiveness of nZVI for reducing the availability and leachability of As in this soil. Soil from a brownfield site was treated with commercial nZVI suspension (NANOFER 25S, NANO IRON, Rajhrad, Czech Republic) at doses 1 and 10%. The availability of As in the soil was evaluated after a sequential extraction procedure developed by Tessier et al. (1979). To quantify As leachability in soil, TCLP (toxicity characteristic leaching procedure) tests were performed following EPA Method 1311 at various contact times (1, 3, 24 and 48 h). The phytotoxicity of soil before and after nZVI treatment was evaluated as germination index according to the standard method of Zucconi et al. (1981). Results from the sequential extraction procedure showed a significant reduction of As in more available fractions after treatment with nZVI. The As leachability also dramatically decreased after nanoparticle application regardless the contact time. Germination tests showed a high phytotoxicity of the brownfield soil which was reduced to moderate toxicity when soils were treated with nZVI. Zero-valent iron nanoparticles has been shown effective for immobilizing As, and, consequently, for minimizing the brownfield toxicity. This study provides evidences that the stabilized ZVI nanoparticles may offer an useful alternative for in situ remediation of As-contaminated soils, more cost-effective and environmentally friendly than other in situ methods. Tessier A, Campbell P.G.C., Bisson M. 1979. Anal. Chem. 51, 844-850. Zucconi, F., A. Pera, and M. Forte. 1981. BioCycle, 2, 54-57. Acknowledgements. This work has been supported by Project CTM 2010-20617-C0202 and EIADES PROGRAM S2009/AMB-1478.