For the water treatment industry, quality is non-negotiable. Consistently demonstrating that regulatory standards are met, while at the same time driving down treatment costs, provides the stimulus for continuous process improvement. Plant stability is the defining operational goal and a primary driver for the adoption of online analytical tools.
Complementary aims are to:
- Confidently meet quality targets even when raw water quality changes sharply and rapidly
- Reduce chemical consumption in the face of rising costs and reduced availability
- Automate monitoring and provide clear and consistent information for operational decision making
- Minimize sludge production and associated disposal costs.
The crucial first step of removing physical contamination via clarification provides a foundation of the entire water treatment process. Coagulant overdosing during changes neutralization is common, and often is considered as insurance against process fluctuations stemming from sub-optimal analysis and control. Taking a hit on chemical usage and sludge production is preferable to compromising water quality.
However, overdosing can re-stabilize suspended particles, decreasing filtration efficiency, as well as increasing treatment costs. The ideal is to maintain the process in a relatively narrow operating window, where just enough coagulant is added to form a stable floc. Reaching this level of performance requires sensitive, relevant and timely monitoring.