title: Drinking water quality monitoring using trend analysis.
abstract: One of the common quality parameters for drinking water is residual aluminium. High doses of residual aluminium in drinking water or water used in the food industry have been proved to be at least a minor health risk or even to increase the risk of more serious health effects, and cause economic losses to the water treatment plant. In this study, the trend index is developed from scaled measurement data to detect a warning of changes in residual aluminium level in drinking water. The scaling is based on monotonously increasing, non-linear functions, which are generated with generalized norms and moments. Triangular episodes are classified with the trend index and its derivative. The severity of the situations is evaluated by deviation indices. The trend episodes and the deviation indices provide good tools for detecting changes in water quality and for process control.
authors.affiliation: University of Oulu, Control Engineering Laboratory, P.O. Box 4300, FIN-90014 University of Oulu, Finland E-mail: jani.tomperi@oulu.fi.
authors.forename: Jani
authors.initials: J
authors.lastname: Tomperi
authors.affiliation: University of Oulu, Control Engineering Laboratory, P.O. Box 4300, FIN-90014 University of Oulu, Finland E-mail: jani.tomperi@oulu.fi.
authors.forename: Esko
authors.initials: E
authors.lastname: Juuso
authors.affiliation: Finnsugar Ltd, Sokeritehtaantie 20, FI-02460 Kantvik, Finland.
authors.forename: Mira
authors.initials: M
authors.lastname: Eteläniemi
authors.affiliation: University of Oulu, Control Engineering Laboratory, P.O. Box 4300, FIN-90014 University of Oulu, Finland E-mail: jani.tomperi@oulu.fi.
authors.forename: Kauko
authors.initials: K
authors.lastname: Leiviskä
mesh_terms: D000535:Aluminum / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D005387:Finland; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D000535:Aluminum