title: Occurrence and fate of ozonation by-products at a full-scale drinking water treatment plant.
abstract: The occurrence and fate of carbonyl compounds as ozonation by-products at a full scale drinking water treatment plant (DWTP) were studied for one year. Raw water and samples after the main treatment processes (pre-ozonation, coagulation/flocculation, sand filtration, main ozonation, filtration through granular activated carbon and chlorination) were collected on a monthly basis. Pre-ozonation led to the formation of carbonyl compounds at concentrations of 67.3 ± 43.3 μg/l as sum of 14 carbonyl compounds whereas lower concentrations were determined after the main ozonation process, 32.8 ± 22.3 μg/l. The dominant compounds were formaldehyde, acetaldehyde, glyoxal and methyl glyoxal contributing to 65% of total carbonyl content. The DOC reactivity in formation of carbonyl compounds varied through the year exhibiting the higher values in spring. Coagulation/flocculation and sand filtration significantly removed (64-80%) the carbonyl compounds formed at the pre-ozonation step. The removal efficiency of filtration through granular activated carbon showed great variation ranging from 15 to 62%. Finally, the concentrations of carbonyl compounds in finished water were low, close to detection limits, revealing the efficiency of DWTP in the removal of this class of ozonation by-products.
authors.affiliation: Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 511 24 Thessaloniki, Greece. Electronic address: apapage@chem.auth.gr.
authors.forename: A
authors.initials: A
authors.lastname: Papageorgiou
authors.affiliation: Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 511 24 Thessaloniki, Greece. Electronic address: dvoutsa@chem.auth.gr.
authors.forename: D
authors.initials: D
authors.lastname: Voutsa
authors.affiliation: Medical School, Aristotle University of Thessaloniki, 511 24 Thessaloniki, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Papadakis
mesh_terms: D000079:Acetaldehyde / Q000032:analysis; D005557:Formaldehyde / Q000032:analysis; D010126:Ozone / Q000032:analysis* / Q000737:chemistry; D011765:Pyruvaldehyde / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical; D005557:Formaldehyde; D010126:Ozone; D011765:Pyruvaldehyde; D000079:Acetaldehyde
keywords: Aldehydes; Drinking water; Formaldehyde; NOM; Ozonation; Water treatment