An automatic coagulant dosage control technology for water purification plants was developed to deal with rapid changes of feed water quality. Control logic was developed to decide coagulant dosage based on aluminum concentration in the mixing tanks. A coagulant-sedimentation process apparatus was installed in December 2010 in a water purification plant, and the coagulant dosage control test using feed water was started. The developed system was confirmed to be effective for managing settled water turbidity and adequacy of coagulant dosage. For actual changes of feed water quality at the water purification plant over more than one year, the developed system was able to maintain settled water turbidity at less than 1.0 mg-kaolin/L in the period of high feed-water turbidity.
- automatic control technology
- coagulation-sedimentation process
- small flocs
- First received 7 April 2014.
- Accepted in revised form 17 July 2014.
- © IWA Publishing 2015