title: Natural attenuation of arsenic in soils near a highly contaminated historical mine waste dump.
abstract: Arsenic-contaminated soils near historical As-rich mine waste in Jáchymov (Czech Rep.), resulting from the smelting and seepage of the mine waste pore water, were studied to examine As partitioning between solid phases and pore waters. Mineralogical and geochemical analyses showed that As is exclusively associated with unidentified amorphous Fe oxyhydroxides, poorly crystalline goethite and hematite as adsorbed and coprecipitated species (with up to 3.2 wt.% As). Adsorption of As by Fe oxyhydroxides is likely to be a major control on the migration of As in the soil pore water containing only up to 15 μg L(-1) As(V). The slight variations in the dissolved As(V) concentrations do not follow the total contents of As in the soil or adsorbed As, but appeared to be a function of pH-dependent sorption onto Fe oxyhydroxides. The geochemical modelling using PHREEQC-2 supported the efficiency of As(V) adsorption by Fe oxyhydroxides in the soil affected by As-rich waste solution seepage. It also suggested that active Fe oxyhydroxides has a strong attenuation capacity in soil that could effectively trap the aqueous As(V) from the unremitting waste seepage for the next approx. 11600 years.
authors: Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors: Petr
authors: P
authors: Drahota
authors: Michal
authors: M
authors: Filippi
authors: Vojtěch
authors: V
authors: Ettler
authors: Jan
authors: J
authors: Rohovec
authors: Martin
authors: M
authors: Mihaljevič
authors: Ondřej
authors: O
authors: Sebek
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D018153:Czech Republic; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry*; D058085:Iron Compounds / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry; D008906:Mining; D008956:Models, Chemical; D012987:Soil / Q000737:chemistry*; D013053:Spectrophotometry; D013816:Thermodynamics; D014866:Waste Products / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D005290:Ferric Compounds; D058085:Iron Compounds; D008903:Minerals; D012987:Soil; D014866:Waste Products; C094886:goethite; C000499:ferric oxide; C092844:ferric oxyhydroxide; D001151:Arsenic