title: Improvement of multi-parameter-based feed-forward coagulant dosing control systems with feed-back functionalities.
abstract: Coagulant dosing control in drinking and wastewater treatment plants (WWTPs) is often limited to flow proportional concepts. The advanced multi-parameter-based dosing control systems have significantly reduced coagulant consumption and improved outlet qualities. Due to the long retention time in separation stages, these models are mostly based on feed-forward (FF) models. This paper demonstrates the improvement of such models with feed-back (FB) concepts with simplifications, making it possible to use even in systems with long separation stages. Full-scale case studies from a drinking water treatment plant and a WWTP are presented. The model qualities were improved by the dosage adjustment of the FB model, ranging from 66% to 197% of the FF model. Hence, the outlet qualities became more stable and coagulant consumption was further reduced in the range of 3.7%-15.5%.
authors.affiliation: Norwegian University of Life Sciences, P.O. Box 5003-IMT, 1432 Aas, Norway E-mail: wei.liu@nmbu.no.
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.affiliation: Norwegian University of Life Sciences, P.O. Box 5003-IMT, 1432 Aas, Norway E-mail: wei.liu@nmbu.no.
authors.forename: H
authors.initials: H
authors.lastname: Ratnaweera
mesh_terms: D003029:Coagulants / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D008962:Models, Theoretical; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D003029:Coagulants; D062065:Wastewater; D014874:Water Pollutants, Chemical