title: Influences of NOM composition and bacteriological characteristics on biological stability in a full-scale drinking water treatment plant.
abstract: The influences of natural organic matter (NOM) and bacteriological characteristics on the biological stability of water were investigated in a full-scale drinking water treatment plant. We found that prechlorination decreased the hydrophobicity of the organic matter and significantly increased the high-molecular-weight (MW) dissolved organic matter, such as biopolymers and humic substances. High-MW organic matter and structurally complex compounds are known to be relatively slowly biodegradable; however, because of the prechlorination step, the indigenous bacteria could readily utilise these fractions as assimilable organic carbon. Sequential coagulation and sedimentation resulted in the substantial removal of biopolymer (74%), humic substance (33%), bacterial cells (79%), and assimilable organic carbon (67%). Rapid sand and granular activated carbon filtration induced an increase in the low-nucleic-acid content bacteria; however, these bacteria were biologically less active in relation to enzymatic activity and ATP. The granular activated carbon step was essential to securing biological stability (the ability to prevent bacterial growth) by removing the residual assimilable organic carbon that had formed during the ozone treatment. The growth potential of Escherichia coli and indigenous bacteria were found to differ in respect to NOM characteristics. In comparison with E. coli, the indigenous bacteria utilised a broader range of NOM as a carbon source. Principal component analysis demonstrated that the measured biological stability of water could differ, depending on the NOM characteristics, as well as on the bacterial inoculum selected for the analysis.
authors.affiliation: Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747, Republic of Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Water Resources Research Institute, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747, Republic of Korea.
authors.forename: Hyun-Chul
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Meyer
authors.affiliation: Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-ro 2511, Sejong 339-700, Republic of Korea; Program in Environmental Technology and Policy, Korea University, Sejong-ro 2511, Sejong 339-700, Republic of Korea.
authors.forename: Sungpyo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747, Republic of Korea. Electronic address: smaeng@sejong.ac.kr.
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Maeng
mesh_terms: D001704:Biopolymers / Q000032:analysis; D002244:Carbon / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis* / Q000382:microbiology*; D004926:Escherichia coli / Q000254:growth & development; D005374:Filtration; D054879:Halogenation; D006812:Humic Substances / Q000032:analysis; D057927:Hydrophobic and Hydrophilic Interactions; D009930:Organic Chemicals / Q000032:analysis; D010126:Ozone / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D001704:Biopolymers; D060766:Drinking Water; D006812:Humic Substances; D009930:Organic Chemicals; D010126:Ozone; D002244:Carbon
keywords: Bacteriological characteristic; Biological stability; Flow cytometry; Natural organic matter; Prechlorination