Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts
Disinfection processes might alter the chemical structure of biological recalcitrant natural organic matter (NOM) in source water to form assimilable organic carbon (AOC), which can be readily utilized by microbes for growth. However, AOC has not been classified as disinfection byproducts (DBPs) bef...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-02-01
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| Series: | Environment International |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0160412019320963 |
| _version_ | 1828494942726520832 |
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| author | Guocheng Huang Tsz-Wai Ng Huan Chen Alex T. Chow Shengwei Liu Po Keung Wong |
| author_facet | Guocheng Huang Tsz-Wai Ng Huan Chen Alex T. Chow Shengwei Liu Po Keung Wong |
| author_sort | Guocheng Huang |
| collection | DOAJ |
| description | Disinfection processes might alter the chemical structure of biological recalcitrant natural organic matter (NOM) in source water to form assimilable organic carbon (AOC), which can be readily utilized by microbes for growth. However, AOC has not been classified as disinfection byproducts (DBPs) before and little is known about the chemical and structural nature of AOC. This study, for the first time, considers the disinfection-induced AOC as DBPs from a microbiological perspective. The AOC formation by three types of disinfection processes, i.e., chlorination, UVC irradiation (254 nm) and photocatalysis represented by TiO2-UVA in drinking water containing two reference NOM materials of Suwannee River and Nordic Reservoir (SRNOM and NRNOM, respectively) were comparatively benchmarked using Pseudomonas aeruginosa as inoculum. Results showed that chlorination caused a substantial increase in AOC content, whereas TiO2-UVA led to a moderate increase in AOC content and UVC rendered the AOC content unchanged, independent of the types of NOM. Molecular weight indicated by spectral slope ratio and fluorescence fingerprint were found to not provide critical information about the AOC formation potential. FTIR and FT-ICR-MS results indicated that the AOC formation by chlorination was attributed to the oxidation and chlorine substitution on aromatic molecules to form molecules with carboxylic- and alcohol- functionalities, as well as chlorinated aromatics. These molecules could be metabolized and assimilated by Pseudomonas species by a catechol pathway. The results obtained in this study can provide valuable insight regarding the selection of proper technologies for disinfection to prevent microbial growth/regrowth in the distributing system and is intended to encourage more thinking and research on AOC as a new prospect of DBPs during disinfection of drinking water. Keywords: Drinking water, Natural organic matter, Assimilable organic carbon, Microbial regrowth, Disinfection byproducts |
| first_indexed | 2024-12-11T12:04:31Z |
| format | Article |
| id | doaj.art-c583834bf7074019b17d24f67fa641d4 |
| institution | Directory Open Access Journal |
| issn | 0160-4120 |
| language | English |
| last_indexed | 2024-12-11T12:04:31Z |
| publishDate | 2020-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Environment International |
| spelling | doaj.art-c583834bf7074019b17d24f67fa641d42022-12-22T01:07:58ZengElsevierEnvironment International0160-41202020-02-01135Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproductsGuocheng Huang0Tsz-Wai Ng1Huan Chen2Alex T. Chow3Shengwei Liu4Po Keung Wong5School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative RegionSchool of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative RegionBaruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, USABaruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, USA; Corresponding authors.School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Corresponding authors.School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative Region; Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Corresponding authors.Disinfection processes might alter the chemical structure of biological recalcitrant natural organic matter (NOM) in source water to form assimilable organic carbon (AOC), which can be readily utilized by microbes for growth. However, AOC has not been classified as disinfection byproducts (DBPs) before and little is known about the chemical and structural nature of AOC. This study, for the first time, considers the disinfection-induced AOC as DBPs from a microbiological perspective. The AOC formation by three types of disinfection processes, i.e., chlorination, UVC irradiation (254 nm) and photocatalysis represented by TiO2-UVA in drinking water containing two reference NOM materials of Suwannee River and Nordic Reservoir (SRNOM and NRNOM, respectively) were comparatively benchmarked using Pseudomonas aeruginosa as inoculum. Results showed that chlorination caused a substantial increase in AOC content, whereas TiO2-UVA led to a moderate increase in AOC content and UVC rendered the AOC content unchanged, independent of the types of NOM. Molecular weight indicated by spectral slope ratio and fluorescence fingerprint were found to not provide critical information about the AOC formation potential. FTIR and FT-ICR-MS results indicated that the AOC formation by chlorination was attributed to the oxidation and chlorine substitution on aromatic molecules to form molecules with carboxylic- and alcohol- functionalities, as well as chlorinated aromatics. These molecules could be metabolized and assimilated by Pseudomonas species by a catechol pathway. The results obtained in this study can provide valuable insight regarding the selection of proper technologies for disinfection to prevent microbial growth/regrowth in the distributing system and is intended to encourage more thinking and research on AOC as a new prospect of DBPs during disinfection of drinking water. Keywords: Drinking water, Natural organic matter, Assimilable organic carbon, Microbial regrowth, Disinfection byproductshttp://www.sciencedirect.com/science/article/pii/S0160412019320963 |
| spellingShingle | Guocheng Huang Tsz-Wai Ng Huan Chen Alex T. Chow Shengwei Liu Po Keung Wong Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts Environment International |
| title | Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts |
| title_full | Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts |
| title_fullStr | Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts |
| title_full_unstemmed | Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts |
| title_short | Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts |
| title_sort | formation of assimilable organic carbon aoc during drinking water disinfection a microbiological prospect of disinfection byproducts |
| url | http://www.sciencedirect.com/science/article/pii/S0160412019320963 |
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