title: Field-analysis of potable water quality and ozone efficiency in ozone-assisted biological filtration systems for surface water treatment.
abstract: Potable water treatment in small communities is challenging due to a complexity of factors starting with generally poor raw water sources, a smaller tax and consumption base that limit capital and operating funds, and culminating in what is typically a less sophisticated and robust water treatment plant for production and delivery of safe, high quality potable water. The design and optimization of modular ozone-assisted biological filtration systems can address some of these challenges. In surface water treatment, the removal of organic matter (e.g., dissolved organic carbon - DOC), inorganic nutrients and other exposure-related contaminants (e.g., turbidity and dissolved solids) from the raw water source is essential. Thus, a combination of chemical and biological oxidation processes can produce an effective and efficient water treatment plant design that is also affordable and robust. To that end, the ozone-assisted biological filtration water treatment plants in two communities were evaluated to determine the efficacy of oxidation and contaminant removal processes. The results of testing for in-field system performance indicate that plant performance is particularly negatively impacted by high alkalinity, high organics loading, and turbidity. Both bicarbonate and carbonate alkalinity were observed to impede ozone contact and interaction with DOC, resulting in lower than anticipated DOC oxidation efficiency and bioavailability. The ozone dosage at both water treatment plants must be calculated on a more routine basis to better reflect both the raw water DOC concentration and presence of alkalinities to ensure maximized organics oxidation and minimization of trihalomethanes production.
authors: Engineering Support & Research, SaskWater, 200-111 Fairford Street East, Moose Jaw, S6H 1C8, Canada; Environmental Systems Engineering, Faculty of Engineering and Applied Science, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada.
authors: Enisa
authors: E
authors: Zanacic
authors: Department of Biology, Faculty of Science, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada.
authors: John
authors: J
authors: Stavrinides
authors: Environmental Systems Engineering, Faculty of Engineering and Applied Science, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada. Electronic address: dena.mcmartin@uregina.ca.
authors: Dena W
authors: DW
authors: McMartin
mesh_terms: D060766:Drinking Water; D005374:Filtration; D010126:Ozone; D014874:Water Pollutants, Chemical; D018508:Water Purification; D060753:Water Quality
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D010126:Ozone
keywords: Biofiltration; Ozonation; Potable water; Small-scale; Surface water treatment; Water quality