Application Note

A Strategy For Optimizing Water Treatment Plant Performance Using Light Scatter Technologies

Source: Hach Company

Two new particle detecting technologies have been developed to help optimize filter performance at water treatment plants (WTP). One nephelometer was designed to give simple, accurate, and rapid response to turbidity changes during a backwash cycle and while monitoring the filter effluent. The other nephelometer was designed specifically to monitor filter effluent. During this study, the instrumentation was primarily used to monitor particle events during the WTP process. The ultimate goal is to optimize plant performance by identifying and reducing particle events that occur either before or after final filtration.

Optimization of the filter run was defined as the production of a stable effluent stream (characterized by low and consistent turbidity and low and consistent particle counts). Particle shedding from the filter into the sample was minimal for the duration of the run.

Two new instruments were used in this study, a laser nephelometer and a probe turbidimeter. The laser nephelometer, which is designed to detect very small changes in turbidity, was combined with a particle counter and regulatory turbidimeter on the filter effluent. The probe turbidimeter exhibits quick response and contains an 860-nm infrared light source, making it immune to color interference. The probe was positioned in the influent immediately above the filter. Collectively, this instrument distribution allows for more in-depth profiling of each particle event as it moves through the filter.