Recovery of Wastewater Treatment Chemicals from Fly Ash
Publication: Journal of Environmental Engineering
Volume 109, Issue 5
Abstract
Fly ash is currently being generated at a rate of millions of tons every year and represents a growing solid waste disposal problem. In an effort to examine alternative uses for this waste product, fly ash was investigated as a source for wastewater treatment chemicals. Through a sequential caustic/acid leaching process, portions of the iron, aluminum, and silica in fly ash were solubilized allowing for the recovery of these materials in a useable form. Synthetic additives derived from this process were evaluated as coagulants in wastewater treatment and as conditioners for sludge prior to mechanical dewatering. Conventional laboratory scale jar tests were conducted for comparing coagulant effectiveness. Sludge conditioners were evaluated by performing vacuum filtration tests using a Buchner Funnel apparatus. The fly ash derived additives performed as well or better than commercially available chemicals. Synergistic activity is believed to occur when using the synthetic materials due to the mutual effectiveness of the solubilized portions of aluminum, iron, and silica present in the treatment additive. The synthetic additives are more cost effective in the treatment of wastewater and sludge than ferric chloride and aluminum sulfate.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Canon, R. M., Gilliam, T. M., and Watson, J. S., “Evaluation of Potential Processes for Recovery of Metals from Coal Ash,” CS‐1992, Volume 1, Oak Ridge National Laboratories, Oak Ridge, Tenn., 1981.
2.
“Chemical Marketing Reporter,” Schnell Publishing Company, Inc., New York, N.Y., Vol. 221, May 3, 1982.
3.
“DR‐EL/2 Methods Manual for Hach DR‐EL/2,” Hach Chemical Company.
4.
Eye, J. D., and Basu, T., “The Use of Flyash in Wastewater Treatment and Sludge Conditioning,” Journal Water Pollution Control Federation, Vol. 42, 1970, p. R125.
5.
Micale, F. J., “A Mechanism for Ash Assisted Sludge Dewatering,” Lehigh University, Bethlehem, Pa., 1976.
6.
Moehle, F. W., “Fly Ash as a Filtering Aid for Dewatering Industrial Waste Plant Sludge,” Proceedings of the 22nd Industrial Waste Conference, Purdue University, West Lafayette, Ind., 1968, p. 429.
7.
“Nalco's Water Clarification Test Procedures,” Nalco Chemical Co., Naperville, Ill.
8.
Rao, D. N., Bakhshi, N. N., and MacDonald, D. G., “Colour Removal from Pulp Mill Effluent Using Fly Ash Acidified with Chlorination Stage Effluent,” Transactions of the Technical Section, Canadian Pulp and Paper Association, Vol. 4, 1978, p. TR77.
9.
Reed, G. D., Mitchell, D. T., and Parker, D. G., “Water Quality Effects of Aqueous Fly Ash Disposal,” Proceedings of the 31st Industrial Waste Conference, Purdue University, Ann Arbor Science, Ann Arbor, Mich., 1976, p. 337.
10.
Reynolds, T. D., Unit Operations and Processes in Environmental Engineering, Brooks/Cole Engineering Division, Monterey, Calif., 1982.
11.
Smith, J. W., “Fly Ash Extraction Evaluations,” Memphis State University, Memphis, Tenn., 1981.
12.
Stanard Methods for the Examination of Water and Wastewater, American Public Health Association‐American Water Works Association‐Water Pollution Control Federation, 15th ed., 1980.
13.
Tenney, M. W., and Cole, T. G., “The Use of Fly Ash in Conditioning Biological Sludges for Vacuum Filtration,” Journal of the Water Pollution Control Federation, Vol. 40, 1968, p. R281.
14.
Thies, T. L., “Sorptive Characteristics of Heavy Metals in Fly Ash—Soil Environments,” Proceedings of the 31st Purdue Industrial Waste Conference, Purdue University, Ann Arbor Science, Ann Arbor, Mich., 1976, p. 312.
15.
Wastewater Treatment Plant Design, Water Pollution Control Federation and American Society of Civil Engineers, New York, N.Y., 1977.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 109 • Issue 5 • October 1983
Pages: 1168 - 1180
Copyright
Copyright © 1983 ASCE.
History
Published online: Oct 1, 1983
Published in print: Oct 1983
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.