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Ion Exchange Treatment of Acid Mine Drainage J. J. STERNER, Engineer Homer Research Laboratories Bethlehem Steel Corporation and H. A. CONAHAN, Consulting Engineer Engineering Department Bethlehem Steel Corporation Bethlehem, Pennsylvania INTRODUCTION Mine water pumped from active mines and flowing from abandoned mines frequently contains relatively high concentrations of dissolved iron (both ferrous and ferric) and acidity as well as other dissolved ions such as aluminum, calcium, and magnesium. Recent legislation by the Commonwealth of Pennsylvania requires the treatment of acid mine drainage (AMD) from active mines to meet the effluent standards established by the Pennsylvania Sanitary Water Board. The key items in this set of standards are: no greater than seven mg/1 iron, alkalinity greater than acidity, and pH between 6. 0 and 9. 0. Lime neutralization of AMD is one treatment that is known to be effective and is currently being used (1). However, the resulting precipitate settles to a final thixotropic sludge which contains hydrated ferric and aluminum hydroxides and may be more than 99 per cent water, i.e., less than one per cent solids. The volume of the sludge produced may amount to more than 10 per cent of the original AMD discharge, depending on the original concentrations of iron and aluminum. The disposal or storage of this sludge, which dries and compacts poorly, represents the most difficult aspect of AMD treatment via lime neutralization. The large storage lagoons, which will be needed to contain this production of sludge, will take the land out of productive service and will be hazardous for many years after being filled. As part of a broad research program directed toward developing more effective and economical methods for handling the AMD problem, we undertook experimental and pilot plant studies of ion exchange as a means for producing a concentrated waste stream which would contain the iron, aluminum, and other cations in AMD and could be handled more conveniently and economically than the sludge from lime neutralization. The estimated regenerant cost for a minimum- volume, concentrated waste stream as well as the solids concentration of sludges obtained by treatment of this waste stream are stated for the particular AMD treated. PILOT PLANT TEST PROGRAM Preliminary experimental work with small fixed beds of ion exchange resins in one-half and one in. diameter glass columns showed that it was technically feasible to remove iron from AMD by ion exchange. On the other hand, the low efficiency of regenerating the resin in the small fixed-bed apparatus made it impractical to determine minimum regenerant requirements or to obtain a highly - 101 -
Object Description
Purdue Identification Number | ETRIWC196810 |
Title | Ion exchange treatment of acid mine drainage |
Author |
Sterner, J. J. Conahan, H. A. |
Date of Original | 1968 |
Conference Title | Proceedings of the 23rd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,15314 |
Extent of Original | p. 101-110 |
Series |
Engineering extension series no. 132 Engineering bulletin v. 53, no. 2 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-05-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 101 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Ion Exchange Treatment of Acid Mine Drainage J. J. STERNER, Engineer Homer Research Laboratories Bethlehem Steel Corporation and H. A. CONAHAN, Consulting Engineer Engineering Department Bethlehem Steel Corporation Bethlehem, Pennsylvania INTRODUCTION Mine water pumped from active mines and flowing from abandoned mines frequently contains relatively high concentrations of dissolved iron (both ferrous and ferric) and acidity as well as other dissolved ions such as aluminum, calcium, and magnesium. Recent legislation by the Commonwealth of Pennsylvania requires the treatment of acid mine drainage (AMD) from active mines to meet the effluent standards established by the Pennsylvania Sanitary Water Board. The key items in this set of standards are: no greater than seven mg/1 iron, alkalinity greater than acidity, and pH between 6. 0 and 9. 0. Lime neutralization of AMD is one treatment that is known to be effective and is currently being used (1). However, the resulting precipitate settles to a final thixotropic sludge which contains hydrated ferric and aluminum hydroxides and may be more than 99 per cent water, i.e., less than one per cent solids. The volume of the sludge produced may amount to more than 10 per cent of the original AMD discharge, depending on the original concentrations of iron and aluminum. The disposal or storage of this sludge, which dries and compacts poorly, represents the most difficult aspect of AMD treatment via lime neutralization. The large storage lagoons, which will be needed to contain this production of sludge, will take the land out of productive service and will be hazardous for many years after being filled. As part of a broad research program directed toward developing more effective and economical methods for handling the AMD problem, we undertook experimental and pilot plant studies of ion exchange as a means for producing a concentrated waste stream which would contain the iron, aluminum, and other cations in AMD and could be handled more conveniently and economically than the sludge from lime neutralization. The estimated regenerant cost for a minimum- volume, concentrated waste stream as well as the solids concentration of sludges obtained by treatment of this waste stream are stated for the particular AMD treated. PILOT PLANT TEST PROGRAM Preliminary experimental work with small fixed beds of ion exchange resins in one-half and one in. diameter glass columns showed that it was technically feasible to remove iron from AMD by ion exchange. On the other hand, the low efficiency of regenerating the resin in the small fixed-bed apparatus made it impractical to determine minimum regenerant requirements or to obtain a highly - 101 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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