Scavenging and immobilization of trace contaminants by colloids in the waters of abandoned ore mines

The geochemistry of rare earth elements (REE) in acid mine drainage from the Sitai coal mine, Shanxi Province, North China

“…Concentrations of REE in low-pH waters dominated by SO 4 2− may significantly increase because of formation of more stable LnSO 4 + (Johannesson and Lyons, 1995;Tabaksblat, 2002). Coagulation and aggregate precipitation of iron and aluminum colloids may effectively remove REE in mine water with increases in pH (Zanker et al, 2003).…”

Molecular characterization of uranium(VI) sorption complexes on iron(III)-rich acid mine water colloids

“…The strongest affinity of U(VI) to hydrous ferric oxides is pH range from 5 to 8, commonly found when acid pore water from the ore deposit or acid mine drainage (AMD) mixes with non-acidic adit water, groundwater, or surface water. This water mixing may occur in the mines, especially in abandoned mines that are subject to flooding (Zänker et al, 2003), in adjacent groundwater aquifers, or in surface waters that are affected by AMD (e.g., Kimball et al, 1995). Chemical reactions such as oxidation, hydrolysis, and precipitation contribute to the formation of colloids and their agglomerates consisting mainly of Fe(III) and Al(III) oxyhydroxides and hydroxysulfates and characterized by a large surface area with many reactive sites of functional groups (Webster et al, 1998;Nordstrom and Alpers, 1999;Lee et al, 2002).…”

Formation of iron-containing colloids by the weathering of phyllite

“…Ferrihydrite, the most probable colloidal iron mineral, for example, can bind significant amounts of toxic trace contaminants common to mine environments such as arsenic (Puls and Powell 1992;Fuller et al 1993;Zänker et al 2000), copper (Kimball et al 1995;Schemel et al 2000), lead (Kimball et al 1995;Schemel et al 2000;Zänker et al 2000), mercury (Lechler et al 1997;Kim et al 2004) or thorium (Short et al 1988;Vilks et al 1988;Lieser et al 1990). Ferrihydrite and other Fe(III) oxides and oxyhydroxides can also strongly adsorb uranium(VI) Payne et al 1994;Bruno et al 1995;Reich et al 1998;Bargar et al 2000;Moyes et al 2000;Arnold et al 2001;Zänker et al 2003) which is of particular interest in the context of our phyllite sample from a uranium mine. Moreover, iron(III)-containing colloids can also influence the transport of nuclear waste related contaminants such as radioiodine (Sätmark et al 1996), plutonium (Kaplan et al 1994) or neptunium (Fujita et al 1995) in oxic waters.…”

“…It is well known that metal contaminant mobility can be significantly influenced by colloids. Colloids can both stimulate (Morel and Gschwend 1987;McCarthy and Zachara 1989;Kim 1994;Honeyman 1999) and retard Packman 2002, 2004;Zänker et al 2003) the transport of contaminants. Colloids are ubiquitous in surface, seepage and ground waters.…”