Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage

Fuel
By: , and 

Links

Abstract

Processes affecting neutralization of acidic coal mine drainage were evaluated within `anoxic' limestone drains (ALDs). Influents had pH≤3.5 and dissolved oxygen <2 mg/l. Even though effluents were near neutral (pH>6 and alkalinity>acidity), two of the four ALDs were failing due to clogging. Mineral-saturation indices indicated the potential for dissolution of calcite and gypsum, and precipitation of Al3+ and Fe3+ compounds. Cleavage mounts of calcite and gypsum that were suspended within the ALDs and later examined microscopically showed dissolution features despite coatings by numerous bacteria, biofilms, and Fe–Al–Si precipitates. In the drain exhibiting the greatest flow reduction, Al-hydroxysulfates had accumulated on limestone surfaces and calcite etch points, thus causing the decline in transmissivity and dissolution. Therefore, where Al loadings are high and flow rates are low, a pre-treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage
Series title Fuel
DOI 10.1016/S0016-2361(98)00147-1
Volume 78
Issue 2
Year Published 1999
Language English
Publisher Elsevier
Description 12 p.
First page 259
Last page 270
Country United States
State West Virginia
Google Analytic Metrics Metrics page
Additional publication details