title: Characteristics transformation of humic acid during ozonation and biofiltration treatment processes.
abstract: Characteristics transformation of humic acid extracted from natural water during the ozonation and biofiltration treatment processes was investigated based on the analyses of total organic carbon, UV absorbance, infrared spectroscopy, and gel permeation chromatography. With ozone doses of 1, 4, and 7 mg/L, high-molecular-weight humic acid was cleaved into low-molecular-weight particles and accumulated at group 6 (molecular weight < or = 4000 g/mole) on the Sephadex G-75 (Pharmacia Fine Chemicals, Uppsala, Sweden) fraction. Furthermore, the molecular-size distribution of organic compounds by Sephadex G-25 was shifted from groups 2 (molecular weight = 4000 to 400 g/mole) and 3 (molecular weight = 400 to 180 g/mole) to groups 2, 3, and 4 (molecular weight < or = 180 g/mole) under ozone doses of 1 and 4 mg/L. An increased ozone dose destroyed functional groups C=C and C-O of aromatic and phenolic compounds and increased UV-insensitive biodegradable organic carbon for subsequent biofiltration.
authors.affiliation: Department of Safety, Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung, Taiwan. yhlinl@ctust.edu.tw
authors.forename: Yen-Hui
authors.initials: YH
authors.lastname: Lin
authors.forename: Hsin-Jung
authors.initials: HJ
authors.lastname: Hsien
mesh_terms: D002244:Carbon / Q000737:chemistry; D002850:Chromatography, Gel; D005374:Filtration; D006812:Humic Substances / Q000032:analysis*; D009930:Organic Chemicals / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013624:Taiwan; D018508:Water Purification
chemical_list: D006812:Humic Substances; D009930:Organic Chemicals; D010126:Ozone; D002244:Carbon