Simultaneous measurement of turbidity and particle concentration

We developed a high-sensitive turbidimeter capable of measuring both turbidity and particle concentration using the relationship between turbidity and particle concentration for each diameter. The relationship is expressed as D = k[Sgr ]niCi, where D is turbidity, k is constant, n is particle concentration, and Ci is mean scattering cross section in diameter class i. This equation can be used to measure turbidity in the range from 0.001 to 2 Kaolin Turbidity Unit (TU). This paper also describes the use of the turbidimeter in a water purification plant. Change in turbidity and particle concentration was observed after backwashing. A sharp rise in particle concentration above 3µm was observed, even for turbidity less than 0.1 TU.