Clean Technology 2010
U. Nobbmann, K.R. Gertig, J.A. Billica, A. Morfesis
Malvern Instruments, Inc., US
zeta potential, drinking water, clarification, flocculation
Zeta potential provides a measurable value to monitor optimal water clarification capabilities. The magnitude of the zeta potential value indicates the repulsive interaction between particles; a zero zeta potential means that the conditions for the aggregation of contaminants are maximized. Drinking water in the US and developed nations of the world is treated to remove contamination of foreign materials, both mineral and organic. Contaminants can be present in almost any water source and can be observed in water supplies obtained from mountains, rivers and soil with even greater contamination potential coming from surface water, domestic sewage and industrial waste. The results of this full-scale case study show that zeta potential measurements can be successfully used by plant operators as a key process control and optimization tool over a twelve month period. While maintaining coagulation targets for pH and zeta potential, the full scale process performance was evaluated with respect to the ability to meet specific goals required for low turbidity, TOC removal and low aluminum residuals. Zeta potential was a key factor in maintaining process control even during challenging seasonal changes that rapidly affected the raw water quality.