Removal of Suspended Clay Particles in Water by Weathered Volcanic Ash-Based Material


  • Nga Nguyen Thi Hang Department of water resources engineering, Thuy Loi University, 175 Tay Son, Dong Da, Ha Noi-100000, Viet Nam


Water treatment, Flocculation, Kaolinite, Montmorillonite, Surface charge neutralization.


The present study aims to investigate removal capacity of suspended clay particles in water by a flocculant prepared from weathered volcanic ash rich in allophane and imogolite. The optimum flocculant dosage and pH values of suspensions required to achieve maximum removal of clay particles were determined. Flocculation experiments of clay suspensions were conducted with jar test device in the laboratory. The results indicate that the flocculant performs well in removing clay particles. The highest efficiency was kaolinite removal approx. 98%), and lower capacity was with montmorilonite (approx. 93%). The optimum solid ratios of 0.2:1 and 1:1 are determined for flocculant to remove kaolinite (Kao) and montmorilonite (Mon). Solution pH affects the clay particle removal. The acidic condition of suspensions enhances flocculation and removal efficiency. Sedimentation time of 20 min is necessary for completed flocculation process of clay particles with flocculant. The results of flocculation tests clay particles also suggest that volcanic ash-based flocculants removed kaolinite particles more effectively than for montmorillonite. 


[1] Faust S.D and Aly, O.M. Chemistry of water treatment. Boston: Butterworth Publisher, 1983, pp. 277-367
[2] Tripathy, T and De Ranjan, B. “Flocculation: A new way to treat the waste water”. Physical Sciences Journal. Vol.10 (1), pp. 93-127, 2006.
[3] O`Melia C.R. Physicochemical Processes for water quality control. New York: Wiley-Interscience, 1972, pp.61-109.
[4] Nakanishi,R and Wada,S.-I. “Reactivity with phosphate and phytotoxicity of hydroxylaluminosilicate ions synthesized by instantaneous mixing of aluminum chloride and sodium orthosilicate solutions”. Soil Science Plant Nutrient, (53), pp.545-550, 2007.
[5] Divakaran. R and Pillai, S. “Flocculation of kaolinite suspensions in water by chitosan”. Water Resources, vol.16(35), pp.3904-3908, 2001.
[6] Nga, N.T.H., Ienaga, Y., Mori, Y. and Wada, S. –I. “Effects of mineralogy of suspended materials on performance of weathered volcanic ash-based flocculant”. Clay Science, vol.(16) pp. 33-39, 2012.
[7] Kuchibune, A., Moromoto, T. and Wada, S.–I. “Preparation of efficient coagulant from clays” in Proc.16th SymposiumonGeo-Environments and Geotechnique, 2006, pp. 63-66. (in Japanese).
[8] Wada, S.I, Umegaki, Y “Major Ion and Electrical Potential Distribution in Soil under Electrokinetic Remediation”. Environment Science Technology, vol.35 (11), pp. 2151–2155, 2001.
[9] Moslehuddin. AZ, Laizoo. S, Egashira. K “Mineralogy and potassium chemistry of Bangladesh paddy soil”. Ph. D dissertation. Kyushu University, Japan, 2001.
[10 ] Blackmore, L.C., Searle, P.L. and Daly, B.K “Methods for chemical analysis of soils”. In New Zealand Soil Beaureau Scientific Report 10A, DSIR, New Zealand, 1998.
[11 ] Follett, E.A.C. “The retention of amorphous, colloidal ferric hydroxide by kaolinites”. Soil Science, vol.16 (2), pp.334–341, 1965.
[12] Weiss. A, Russow. J. “ Uber die lage der austauschbaren in Process of International Clay Conference, Stockholm, 1963, pp. 201- 203
[13] Nasser, M.S., James, A.E. “The effect of electrolyte concentration and pH on the flocculation and Rheological behavior of kaolinite suspensions”. Engineering science and technology, vol. 4 (4), pp.430-446, 2009.




How to Cite

Hang, N. N. T. (2017). Removal of Suspended Clay Particles in Water by Weathered Volcanic Ash-Based Material. American Academic Scientific Research Journal for Engineering, Technology, and Sciences, 35(1), 58–66. Retrieved from