|   | 
Details
   web
Records
Author McConchie, D.M.; Clark, M.; Hanahan, C.; Baun, R.
Title New treatments for the old problems of acid mine drainage and sulphidic mine tailings storage Type Journal Article
Year 2000 Publication Abbreviated Journal
Volume Issue Pages
Keywords (up) acid mine drainage; ash; carbonate rocks; clastic sediments; construction materials; crushed stone; hydroxides; iron hydroxides; iron oxides; mines; mud; oxides; pH; pollution; reclamation; red mud; remediation; sea water; sedimentary rocks; sediments; storage; sulfides; tailings; waste management 22, Environmental geology
Abstract
Address
Corporate Author Thesis
Publisher Programme & Abstracts - International Symposium on Environmental Geochemistry (ISEG), vol.5 Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title 5th international symposium on Environmental geochemistry; conference abstracts and scientific programme Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes 2006-033067; 5th international symposium on Environmental geochemistry, Cape Town, South Africa, April 2004; GeoRef; English Approved no
Call Number CBU @ c.wolke @ 5858 Serial 304
Permanent link to this record
 

 
Author Cravotta, C.A., III; Trahan, M.K.
Title Limestone drains to increase pH and remove dissolved metals from acidic mine drainage Type Journal Article
Year 1999 Publication Appl. Geochem. Abbreviated Journal
Volume 14 Issue 5 Pages 581-606
Keywords (up) manganese oxide redox processes sulfate waters iron-oxides adsorption ions oxidation surfaces environments aluminum
Abstract Despite encrustation by Fe and Al hydroxides, limestone can be effective for remediation of acidic mine drainage (AMD). Samples of water and limestone (CaCO3) were collected periodically for 1 a at 3 identical limestone-filled drains in Pennsylvania to evaluate the attenuation of dissolved metals and the effects of pH and Fe- and Al-hydrolysis products on the rate of CaCO3 dissolution. The influent was acidic and relatively dilute (pH < 4; acidity < 90 mg) but contained 1-4 mg . L-1 of O-2, Fe3+, Al3+ and Mn2+. The total retention time in the oxic limestone drains (OLDs) ranged from 1.0 to 3.1 hr. Effluent remained oxic (O-2 > 1 mg . L-1) but was near neutral (pH = 6.2-7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs, The hydrous oxides, nominally Fe(OH)(3) and Al(OH)(3), were visible as loosely bound, orange-yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)(3) and Al(OH)(3) particles were transported downflow. The accumulation of hydrous oxides and elevated pH (> 5) in the downflow part of the OLDs promoted sorption and coprecipitation of dissolved Mn, Cu, Co, Ni and Zn as indicated by decreased concentrations of the metals in effluent and their enrichment relative to Fe in hydrous-oxide particles and coatings on limestone. Despite thick (similar to 1 mm) hydrous-oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within and the OLD where the limestone was not coated. The high rates of CaCO3 dissolution and Fe(OH3) precipitation were associated with the relatively low pH and high Fe3+ concentration near the inflow. The rate of CaCO3 dissolution decreased with increased pH and concentrations of Ca2+ and HCO3- and decreased Pco(2). Because overall efficiency is increased by combining neutralization and hydrolysis reactions, an OLD followed by a settling pond requires less land area than needed for a two-stagetreatment system consisting of an anoxic limestone drain and oxidation-settling pond or wetland. To facilitate removal of hydrous-oxide sludge, a perforated-pipe subdrain can be installed within an OLD. (C) 1999 Elsevier Science Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0883-2927 ISBN Medium
Area Expedition Conference
Notes Jul; Limestone drains to increase pH and remove dissolved metals from acidic mine drainage; Isi:000080043300004; file:///C:/Dokumente%20und%20Einstellungen/Stefan/Eigene%20Dateien/Artikel/10102.pdf; AMD ISI | Wolkersdorfer Approved no
Call Number CBU @ c.wolke @ 17470 Serial 22
Permanent link to this record