Particulate and THM Precursor Removal with Ferric Chloride
Publication: Journal of Environmental Engineering
Volume 125, Issue 11
Abstract
Pilot-scale experiments were performed to investigate the effectiveness of enhanced coagulation in removing particles and trihalomethane (THM) precursors from two surface source waters: California State Project water and Colorado River water. The removal of suspended particles and natural organic matter at various ferric chloride doses and coagulation pHs was assessed through source water and filter effluent measurements of turbidity, particle count, UV254, TOC, and THM formation potential. Overall, it was found that optimal removal of particles and THM precursors by enhanced coagulation with ferric chloride is obtained at high coagulant doses (>16 mg/L) and low pH conditions. Generally, turbidity removal is more efficient and head loss is more moderate at ambient pH compared with pH 5.5. Additionally, filter effluent particle counts were found to be consistent with residual turbidity data. The removal of THM precursors by enhanced coagulation is significantly enhanced at pH 5.5 compared with ambient pH. The reduction in THM formation potential is consistent with the trends observed for the THM precursor removal data (i.e., UV254 and TOC data). Furthermore, specific UV absorbance was used to estimate the proportion of humic substances in the raw waters. Enhanced coagulation was found to be less effective for the source water with the lower specific UV absorbance.
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References
1.
Amirtharajah, A., Dennett, K. E., and Studstill, A. (1993). “Ferric chloride coagulation for removal of dissolved organic matter and trihalomethane precursors.” Water Sci. and Technol., 27(11), 113–121.
2.
Amirtharajah, A., and O'Melia, C. R. ( 1990). “Coagulation processes: Destabilization, mixing, and flocculation.” Water quality and treatment, F. W. Pontius, ed., McGraw-Hill, New York, 269–365.
3.
Amy, G. L., Collins, M. R., Kuo, C. J., Chowdhury, Z. K., and Bales, R. C. ( 1989). “Effects of humic substances on particle formation, growth, and removal during coagulation.” Aquatic humic substances: Influence on fate and treatment of pollutants, I. H. Suffet and P. MacCarthy, eds., American Chemical Society, Washington, D.C., 443–452.
4.
Bottero, J. Y., and Bersillon, J. L. ( 1989). “Aluminum and iron(III) chemistry: Some implications for organic substance removal.” Aquatic humic substances: Influence on fate and treatment of pollutants, I. H. Suffet and P. MacCarthy, eds., American Chemical Society, Washington, D.C., 425–442.
5.
Cheng, R. C., Krasner, S. W., Green, J. F., and Wattier, K. L. (1995). “Enhanced coagulation: A preliminary evaluation.” J. AWWA, 87(2), 91–103.
6.
Ching, H.-W. ( 1994). “Removal of particles and THM precursors from surface water by coagulation and granular filtration,” PhD dissertation, University of California, Los Angeles.
7.
Ching, H.-W., Elimelech, M., and Hering, J. G. (1994). “Dynamics of coagulation of clay particles with aluminum sulfate.”J. Envir. Engrg., ASCE, 120(1), 169–189.
8.
Crozes, G., White, P., and Marshall, M. (1995). “Enhanced coagulation: Its effect on NOM removal and chemical costs.” J. AWWA, 87(1), 78–89.
9.
Dempsey, B. A. (1984). “Removal of naturally occurring compounds by coagulation and sedimentation.” CRC Critical Rev. in Envir. Control, 14(4), 311–331.
10.
Dempsey, B. A., Ganho, R. M., and O'Melia, C. R. (1984). “The coagulation of humic substances by means of aluminum salts.” J. AWWA, 76(4), 141–150.
11.
Dennett, K. E., Amirtharajah, A., Moran, T. F., and Gould, J. P. (1996). “Coagulation: Its effect on organic matter.” J. AWWA, 88(4), 129–142.
12.
Dennett, K. E., Amirtharajah, A., Studstill, A., Moran, T. F., and Gould, J. P. ( 1995). Humic substance removal and minimization of trihalomethanes by ferric chloride coagulation. American Water Works Association Research Foundation, Denver.
13.
“Disinfectants and disinfection byproducts. Final rule.” (1998). Federal Register, 63(No. 241), Dec. 16, 69390.
14.
Edwards, G. A., and Amirtharajah, A. (1985). “Removing color caused by humic acids.” J. AWWA, 77(3), 50–57.
15.
Edzwald, J. K., Becker, W. C., and Wattier, K. L. (1985). “Surrogate parameters for monitoring organic matter and THM precursors.” J. AWWA, 77(4), 122–132.
16.
Hall, E. S., and Packham, R. F. (1965). “Coagulation of organic color with hydrolyzing coagulants.” J. AWWA, 57(9), 1149–1163.
17.
Hubel, R. E., and Edzwald, J. K. (1987). “Removing trihalomethane precursors by coagulation.” J. AWWA, 70(7), 98–106.
18.
“Interim enhanced surface water treatment rule. Final rule.” (1998). Federal Register, 63(No. 241), Dec. 16, 69478.
19.
Johnson, P. N., and Amirtharajah, A. (1983). “Ferric chloride and alum as single and dual coagulants.” J. AWWA, 75(5), 232–239.
20.
Kavanaugh, M. C. (1978). “Modified coagulation for improved removal of trihalomethane precursors.” J. AWWA, 70(11), 613–620.
21.
Koch, B., Crofts, E. W., Schimpff, W. K., and Davis, M. K. (1988). “Analysis of halogenated disinfection by-products by capillary chromatography.” Proc., Water Quality Technol. Conf., American Water Works Association, St. Louis.
22.
Koch, B., Krasner, S. W., Sclimenti, M. J., and Schimpff, W. K. (1991). “Predicting the formation of DBPs by the simulated distribution system.” J. AWWA, 83(10), 62–70.
23.
Krasner, S. W., and Amy, G. (1995). “Jar-test evaluations of enhanced coagulation.” J. AWWA, 87(10), 93–107.
24.
Liang, L., and Morgan, J. J. (1990). “Chemical aspects of iron oxide coagulation in water: Laboratory studies and implications for natural systems.” Aquatic Sci., 52(1), 32–55.
25.
Montgomery, J. M. (1985). Water treatment principles and design. Wiley, New York.
26.
Najm, I. N., Patania, N. L., Jacangelo, J. G., and Krasner, S. W. (1994). “Evaluating surrogates for disinfection by-products.” J. AWWA, 86(6), 98–106.
27.
O'Melia, C. R. ( 1972). “Coagulation and flocculation.” Physicochemical processes for water treatment control, W. J. Weber, ed., Wiley, New York, 61–109.
28.
O'Melia, C. R. (1985). “Particles, pretreatment, and performance in water treatment.”J. Envir. Engrg., ASCE, 111(6), 874–890.
29.
Pontius, F. W. (1999). “Complying with future water regulations.” J. AWWA, 91(3), 46–58.
30.
Randtke, S. J. (1988). “Organic contaminant removal by coagulation and related process combinations.” J. AWWA, 80(5), 40–56.
31.
Vrijenhoek, E. M., Childress, A. E., Elimelech, M., Tanaka, T. S., and Beuhler, M. D. (1998). “Removing particles and THM precursors by enhanced coagulation.” J. AWWA, 90(4), 139–150.
Information & Authors
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Published In
Journal of Environmental Engineering
Volume 125 • Issue 11 • November 1999
Pages: 1054 - 1061
History
Received: Dec 16, 1998
Published online: Nov 1, 1999
Published in print: Nov 1999
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