International Journal of Environmental Science and Development

Abstract—The fractal dimension of floc provides the basic information on the structure and origin of the flocs. The removal efficiency of several drinking water contaminants depends upon the floc characteristics especially in their fractal dimension in the conventional (coagulation/flocculation) water treatment process. In this study two synthetic feed suspensions (humic acid and clay suspension) were prepared and coagulated under optimum coagulation conditions. Aluminum sulfate (alum, Al2(SO4)3.18H2O) was used as a principal coagulant for both humic acid and clay suspensions. The flocs so produced were measured for their size and fractal dimension distribution as a function of flocculation time using small angle light scattering (SALS) technique. Results showed that floc size increases with an increase in the flocculation time both for humic acid and clay flocs. Same is true for fractal dimensions of humic acid and clay flocs. Fractal dimensions of humic acid flocs were somewhat higher than the fractal dimension of clay flocs due to the difference in coagulation mechanism involved for the formation of humic acid and clay flocs.

Index Terms—Fractal dimension distribution, floc size distribution, small angle light scattering, velocity gradient.

Hira Amjad is with the Institute of Environmental Sciences and Technology(IESE), National University of Sciences and Technology (NUST), Islamabad, Pakistan (e-mail: hiraamjad@iese.nust.edu.pk).
Zahiruddin Khan was with IESE, NUST, Pakistan. He is now with Punjab Saaf Pani Company, Lahore, Pakistan (e-mail: cto.pspc@gmail.com).

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Cite: Hira Amjad and Zahiruddin Khan, "A Comparison of Fractal Dimensions of Clay and Humic Acid Flocs under Optimum Coagulation Conditions," International Journal of Environmental Science and Development vol. 7, no. 4, pp. 240-243, 2016.