Removal of Dyes by Aqueous Mixed Coagulants

Peik Yin Ooi(1), Tjoon Tow Teng(2), A. K. Mohd Omar(3), N. A. R. Nik Norulaini(4*)

(2) Environmental Technology Division School of Industrial Technology University Science of Malaysia 11800 Minden, Penang MALAYSIA
(4) School of Distance Education University Science of Malaysia
(*) Corresponding Author


Alum, MgCl2, and mixtures of alum and MgCl2 have been used as coagulant to remove coloring matter in the reactive dye Levafix Brill Blue EBRA. The jar test was used to determine the effectiveness and the optimal condition of the coagulation process in terms of pH of the coagulation process, coagulant dosage, percentage color removal, and floc settling time. Coagulant dosages of 1,000-5,000 ppm were studied. The treatment of textile industry wastewater was done in the treatment plant of a printing mill. The results showed that coagulation by MgCl2 and alum occurs at the removal pH ranges of 10.5-11.0 for MgCl2 and 4.0-6.0 for alum. The mixtures of MgCl2 and alum gave two distinct effective color-removal zones at pH 4-5.5 and pH 8-9.5. The addition of alum to MgCl2 shifted the optimal pH of MgCl2 from 10.5-11. 0 to 8. 0-9.5. The alum dose of 1,000-3,000 ppm in the coagulant mixture increased by 10-25 % the color removal in the alkaline zone. Floc settling time was found to (a) increase with coagulant dose and (b) take longer in the acidic color-removal zone than in the alkaline zone. The presence of alum increased the floc settling time in the alkaline zone. The study done at the treatment plant of a printing mill showed similar results. A mixture of 60% MgClz and 40% alum at an average dosage of 2,800 ppm gave a color removal of 97% and reductions of 88% for COD and 69% for suspended solids. Keywords: Chemical coagulation, color reduction, mixed coagulants, and textile waste.


Chemical coagulation, color reduction, mixed coagulants, and textile waste

Full Text:



  1. American Public Health Association. (1980). Standard methods for the examination of water and wastewater, 16th ed., APHA, Washington, D.C.
  2. Ajmal, M., and Khan, A. U. (1985). "Effect of factory effluenton soil and crop plant," J. Envir. Pollut. Ser. A., 37, 131-148.

  3. Beas, C. F., and Mesmer, R. E. (1976). The hydrolisis of cations, John Wiley & Sons, Inc., New York, 95.

  4. Black, A. P., and Christman, R. F. (1961). "Electrophoretic studies of sludge particles produced in lime-soda softening," J. Am. Wat. Wks. Assoc., 53, 737-747.

  5. Cooper, P. (1995). “Removing color from dyehouse waste waters," Asian Textile J., 3, 49–58.

  6. Dentel, S. K., and Gossett, J. M. (1988). “Mechanisms of coagulation with aluminum salts," J. Am. Wat. Wks. Assoc., 80, 187-198.

  7. Dziubek, A. M., and Kowal, A. L. (1983). "Water treatment by coagulation-adsorption with dolomite," Chemistry for protection of environment. In: Proceedings of an International Conference, Toulouse, France, 205.

  8. Edzwald, J. K. (1986). "Conventional treatment and direct filtration, treatment and removal of total organic carbon and trihalomethane precursors." In N. M. Ram, E. J. Calabrese, and R. F. Christman, eds. Carcinogens in drinking water, John Wiley & Sons, New York.

  9. El-Geundi, M. S. (1991). "Color removal from textile effluents by adsorption techniques," Wat. Res., 25, 271–273.

  10. Folkman, Y., and Wachs, A. M. (1973). "Removal of algae from stabilization pond effluents by lime treatment," Wat. Res., 7, 419-435.

  11. Gould, J. P., and Groff, K. A. (1987). "Kinetics of ozonolysis of synthetic dyes," Ozone Sci. Eng., 9, 153-167.

  12. Grau, P. (1991). "Textile industry wastewaters treatment," Wat. Sci. Technol., 24, 97--103.

  13. Gurnham, C. F (1965). Industrial waste control, Academic Press, New York.

  14. Hundt, T. R., and O'Melia, C. R. (1988). "Aluminium fulvic acid interactions: Mechanisms and applications," J. Am. Wat. Wks. Assoc., 80, 176-186.

  15. Johnson, P. N., and Amirtharajah, A. (1983). “Ferric chloride and alum as single and dual coagulants," J. Am. Wat. Wks. Assoc., 75, 232-239.

  16. Judkins, J. F, and Hornsby, J.J.S. (1978). “Color removal from textile dye waste using magnesium carbonate [J]," J. Water Pollution Control Federation, 50, 12, 2 446 456.

  17. Kuo, W.G. (1992). "Decolorizing dye wastewater with Fenton's reagent," Wat. Res., 26, 881-886.

  18. Leentvaar, J., and Rebhun, M. (1982). "Effect of magnesium and calcium precipitation on coagulation-flocculation with lime," Wat. Res., 16, 655-662.

  19. Lei, L., Hu, X., Chu, H.P., and Yue, P. L. (1998). "Improved wet oxidation for the treatment of dyeing wastewater concentrate from membrane separation process," Wat. Res., 32, 2753-2759.

  20. Liao, M. Y., and Randtke, S.J. (1986). "Predicting the removal of soluble organic contaminants by lime softening," Wat. Res., 20, 27-35.

  21. Lin, S. H., and Chen, M. L. (1997). "Treatment of textile wastewater by chemical methods for reuse." Wat. Res., 31, 868-876.

  22. Lin, S.H., and Lin, C.M. (1993). "Treatment of textile waste effluents by ozonation and chemical coagulation," Wat. Res., 27, 1743–1748.

  23. Lin, S, H., and Peng, C. F. (1996). "Continuous treatment of textile wastewater by combined coagulation, electrochemical oxidation and activated sludge," Wat. Res., 30, 587–592

  24. Lin, S. H., and Peng, C. F (1994). "Treatment of textile wastewater by electrochemical method,” Wat. Res., 28, 277–282.

  25. Matijevic, E., Abramson, M. B., Ottewill, R. H., Schulz, K. F., and Kerker, M. (1961). "Adsorption of thorium ions on silver iodide sols," J. Phys. Chem., 65, 1724-1729.

  26. O'Melia, C. R., and Stumm, W. (1967). "Aggregation of silica dispersions by iron (III)," J. Coll. Interface Sci., 23, 437–447.

  27. Randtke, S. J. (1988). “Organic contaminant removal by coagulation and related process combinations," J. Am. Wat. Wks. Assoc., 80, 40–56.

  28. Sarasa, J., Roche, M. P., Ormad, M. P., Gimeno, E., Puig, A., and Ovelleiro, J. L. (1998). “Treatment of a wastewater resulting from dyes manufacturing with ozone and chemical coagulation," Wat. Res., 32, 2721-2727.

  29. Skoog, D. A., West, D.M., and Holler, F. J. (1994). Analytical chemistry: An introduction, 6th ed., Saunders College Publishing/ Publication, Philadelphia, USA.

  30. Solozhenko, E. G., Soboleva, N. M., and Goncharuk, V. V. (1995). “Decolorization of azodye solutions by Fenton's oxidation," Wat. Res., 29, 2206-2210.

  31. Stephenson, R. J., and Duff, S. J. B. (1996). "Coagulation and precipitation of a mechanical pulping effluent—I. Removal of carbon, color and turbidity." Wat. Res., 30, 781-792

  32. Sun, G., and Xu, X. (1997). "Sunflower stalks as adsorbents for color removal from textile wastewater," ind. Eng. Chem. Res., 36, 808–812.

  33. Tan, B. H., Teng, T. T., and Mohd Omar, A. K. (2000). "Removal of dyes and industrial dye wastes by magnesium chloride," Wat. Res., 34, 597-601.

  34. Van Benschoten, J. E., and Edzwald, J.K. (1990). "Chemical aspects of coagulation using aluminum salts: II. Coagulation of fulvic acid using alum and polyaluminum chloride," Wat. Res., 24, 1527–1535.

  35. Van Benschoten, J. E., and Edzwald, J.K. (1990). "Chemical aspects of coagulation using aluminum salts: II. Coagulation of fulvic acid using alum and polyaluminum chloride," Wat. Res., 24, 1527–1535.


Article Metrics

Abstract views : 1351 | views : 1031


  • There are currently no refbacks.

ASEAN Journal of Chemical Engineering  (print ISSN 1655-4418; online ISSN 2655-5409) is published by Chemical Engineering Department, Faculty of Engineering, Universitas Gadjah Mada.