ABSTRACT
This chapter explores the nature and properties of typical particles found in raw water to demonstrate the need to grow the small raw water particles to larger flocs for better removal. It deals with the time and intensity of mixing as important determinants for effective coagulation and flocculation. Turbidity is the conventional and most common analytical method to quantify the suspended particle concentration in water. It is an indirect measure, as it only measures the attenuation of a light beam directed through the suspension. It stands to reason that turbidity, while it may provide a quick and easy measure of particle concentration, does not provide a sufficiently detailed tool for more in-depth analysis. Filter sand has limited storage capacity for holding the flocs removed from the raw water. Almost all particles occurring naturally in water have negative surface charge, owing to the molecular structure of clay.
