Blacksburg, Va., Michael F. Hochella Jr., professor of geochemistry and mineralogy at Virginia Tech, has received the prestigious Humboldt Research Award to work in Germany on acid-mine drainage.
"Acid-mine drainage is an environmental problem of vast proportion," said Hochella, professor of geological sciences. In a 1998 collaboration when Hochella was a Fulbright Senior Scholar, he and Andrew Putnis from Universitt Mnster gained a detailed understanding the first time this had been done of the way toxic metals can be transported so far from the mining sites, sometimes hundreds of kilometers.
They also studied where acid-mine drainage originates and is most acute. With the Humboldt award, the two researchers will continue the most critical phase of this work by collecting and interpreting data from drainages coming from two major acid-mine drainage sites, one in Germany and one in the United States.
"Mineral-water interfacial interactions associated with working and abandoned sulfide-bearing mines and mining wastes are among the most complex, dynamic, and environmentally important of all near-surface rock-water systems," according to Hochella.
"These mining sites, numbering more than 200,000 in the United States and Germany alone, typically release large amounts of metals into the environment, ranging up to hundreds of kilometers along hydrologic gradients in a relatively short time. Contamination occurs when high solute concentrations of iron and other more toxic metals form during the weathering of pyrite and associated metal sulfides. These acidic effluent flows, from mine entrances and waste piles, mix with air and oxygenated surface water and precipitate metal oxides, oxyhydroxides, and/or hydroxysulfates."
These phases form mineral/rock coatings and sediments down to the nanometer scale that may contain very high concentrations of contaminating metalsup to percent levels of, for example, copper, zinc, and leadand can be tra
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