Studies on densification of coal mine drainage sludge.
Contributors: United States. Environmental Protection Agency.
Series: Water pollution control research series
Publisher: [Environmental Protection Agency, Water Quality Office]; for sale by the Supt. of Docs., U.S. Govt. Print. Off.
Published: 1971
Place of publication: Washington
Language: eng
Number of pages: 113
Subjects: Acid mine drainage.; Sewage sludge -- Drying.
Description: Bench scale batch experiments were performed on sludges obtained from line neutralization of coal mine drainage in an attempt to alleviate present problems in sludge handling and disposal. Tests were of an exploratory nature and did not afford sufficient data for cost analyses. Ferro Magnetic sludge densification, filter aids, coagulant aids, heating, freeze drying, and coprecipitation of calcium carbonate through addition of CO₂ were tested. Of these, freeze drying, CO₂ addition, and ferro magnetic treatment were shown to be feasible alternatives to present disposal methods. Each of these methods resulted in settled sludge volume reduction of approximately 90% and increases in sludge solids contents of from 0.5 to about 5% after 30 min. settling periods. The ferro magnetic process has the advantages of possible recovery of a useful product, and elimination of costly settling lagoons, but is very sensitive to aluminum and requires a considerable amount of heat. Sludge freezing is the simplest conceptual approach and is apparently effective for any lime produced sludge. The CO₂ addition method offers the possibility of partial recovery and recycling of both CaO and CO₂ through sludge calcination.
Notes: Includes bibliographical references.
"[Prepared] for the Environmental Protection Agency."
"14010 EJT 09/71."