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Acid neutralization within limestone sand reactors receiving coal mine drainage

January 1, 2005

Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity = 31.22 + 2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30 s/30 s to 10 s/50 s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent. ?? 2005 Elsevier Ltd. All rights reserved.

Citation Information

Publication Year 2005
Title Acid neutralization within limestone sand reactors receiving coal mine drainage
DOI 10.1016/j.envpol.2005.01.026
Authors B.J. Watten, P.L. Sibrell, M.F. Schwartz
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Pollution
Series Number
Index ID 70027919
Record Source USGS Publications Warehouse
USGS Organization

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