Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts
Formation of assimilable organic carbon (AOC) during drinking water disinfection: A microbiological prospect of disinfection byproducts
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饮用水消毒过程中可同化有机碳（AOC）的形成：消毒副产物的微生物学前景
DOI：
10.1016/j.envint.2019.105389
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发表时间：
2019
影响因子：
11.8
通讯作者：
Wong Po Keung
中科院分区：
文献类型：
--
作者：
Huang Guocheng;Ng Tsz-Wai;Chen Huan;Chow Alex T.;Liu Shengwei;Wong Po Keung
消毒过程可能改变水源水中生物可吸收的天然有机物（NOM）的化学结构，形成可同化的有机碳（AOC），使微生物易于利用AOC进行生长。然而，AOC以前没有被归类为消毒副产物（DBPs），对AOC的化学和结构性质知之甚少。本研究首次从微生物学角度将消毒诱导的AOC视为DBP。通过三种类型的消毒过程，即，以铜绿假单胞菌（Pseudomonasaerodensosa）为接种物，对含两种参比NOM材料（分别为SRNOM和NRNOM）的SuwanneRiver和NordicReservoir饮用水中的氯化、UVC照射（254 nm）和TiO 2-UVA代表的紫外线进行了比较。结果表明，氯化导致AOC含量大幅增加，而TiO 2-UVA导致AOC含量的适度增加和UVC呈现AOC含量不变，独立于NOM的类型。光谱斜率比和荧光指纹所示的分子量被发现不提供关键信息的AOC形成潜力。FTIR和FT-ICR-MS结果表明，AOC的生成是由于芳烃分子发生氧化和氯取代反应，生成含羧基和醇官能团的分子，以及氯代芳烃。这些分子可以通过邻苯二酚途径被假单胞菌代谢和同化。本研究结果可为选择合适的消毒技术以防止配水系统中微生物的生长/再生长提供有价值的见解，并旨在鼓励更多的思考和研究AOC作为消毒副产物在饮用水消毒中的新前景。
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 usingPseudomonas aeruginosaas 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 byPseudomonasspecies 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.