Drinking Water Engineering and Science Discussions www.drink-water-eng-sci-discuss.net 1996-9473 1996-9481 4 1 2011 10.5194/dwesd-4-151-2011 http://www.drink-water-eng-sci-discuss.net/4/151/2011/ http://www.drink-water-eng-sci-discuss.net/4/151/2011/dwesd-4-151-2011.html http://www.drink-water-eng-sci-discuss.net/4/151/2011/dwesd-4-151-2011.pdf 151 172 2011-12-07 A new model for the simplification of particle counting data M. F. Fadal J. Haarhoff jhaarhoff@uj.ac.za S. Marais Department of Civil Engineering Science, University of Johannesburg, South Africa Process Technology Department, Rand Water, South Africa This paper proposes a three-parameter mathematical model to describe the particle size distribution in a water sample. The proposed model offers some conceptual advantages over two other models reported on previously, and also provides a better fit to the particle counting data obtained from 321 water samples taken over three years at a large South Africa water utility. By using the data from raw water samples taken from a moderately turbid, large surface impoundment, as well as samples from the same water after treatment, typical ranges of the model parameters are presented for both raw and treated water. Once calibrated, the model allows the calculation of total particle number and volumes over any randomly selected size interval of interest. Ceronio, A. D. and Haarhoff, J.: An improvement on the power law for the description of particle size distribution in potable water treatment, Water Res., 39, 305–313, 2005. Lawler, D. F.: Particle size distributions in treatment processes: theory and practice, in: Proceedings of the Fourth International Conference: The role of particle characteristics in separation processes, IAWQ-IWSA Joint Specialist Group on Particle Separation, Jeruslaem, 29–30 October 1996, 1997. Wilczak, A., Howe, E. W., Aleta, E. M., and Lee, R. G.: How pre-oxidation affects particle removal during clarification and filtration, Journal of the American Water Works Association, 94, 85–94, 1992.