-
天然有机物(natural organic matter, NOM)是由腐殖酸、黄腐酸、低分子质量有机酸、碳水化合物、蛋白质等组成的复杂非均相混合物[1]。地表水中的NOM主要来源于周边流域的自然生态系统和人为活动[2],并受气候和季节变化的影响[3]。NOM中可通过0.45 μm过滤器的部分可以定义为DOM(dissolved organic matter, DOM)[4]。在水处理过程中,DOM作为前体物会与消毒剂(如氯、氯胺和臭氧等)发生一系列氧化、取代和水解反应,生成消毒副产物(disinfection by-products, DBPs)[5]。DBPs因具有较高的细胞毒性、致突变性和致癌性,会导致呼吸系统、生殖发育、肝脏、肾脏、神经及免疫系统等方面的健康问题[6-7]。尽管DBPs生成不可避免,我们仍可通过改变DOM的数量和性质来控制DBPs的形成[8]。有研究表明,相较于改变消毒条件或引入其他先进技术去除已形成的DBPs,在消毒前去除DBPs前体物更具经济性[9-10]。因此,了解水源水中DOM的特征及其与DBPs生成的关系,对于保障水处理厂达到预期出水水质具有重要意义[11-12]。
DOM的化学组成显著受季节变化影响。例如,深圳市水源水在雨季主要富含类腐殖质荧光组分,而旱季则以类蛋白质荧光组分为主[13];珠江口的DOM在雨季的相对分子质量高于旱季[14]。这些变化不仅影响着水处理过程,也与DBPs生成密切相关。具体来说,类腐殖质组分与三卤甲烷(trihalomethanes, THMs)和卤乙酸(haloacetic acids, HAAs)等DBPs的生成显著相关;低分子质量DOM在水处理过程中难得到有效去除,而其生成DBPs的能力高于高分子质量DOM[15–17]。此外,水体类型也会影响DOM变化规律,水库由于其庞大的存水量和混合流入水的能力,其水质稳定性高,所以其DOM受季节变化影响程度远低于河流水。
当前,对人工修建的大型自流式长距离调水工程中DOM变化规律的研究较少。该工程采用明渠输水,且水深相对较浅,易引发藻类过度生长。藻华和腐殖化是引起DOM构成变化的2个主要因素[18]。因此,本研究在冬季和夏季于长距离调水工程主干渠采集水样,采用EEMs和HPSEC-OCD对水样中的DOM进行了表征,并对加入过量氯消毒后水样中消毒副产物生成势(disinfection by-products formation potential, DBPsFP) 进行了测定,为揭示样品中DOM沿线变化特征及季节变化对其的影响,探究了DOM组分与THMs、HAAs、卤代酮(halogenated ketones, HKs)和卤乙醛(haloacetaldehydes, HALs)等含碳消毒副产物(carbon containing disinfection by-products, C-DBPs)以及卤乙腈(haloacetonitrile, HANs)、卤乙酰胺(haloacetamides, HAMs)等含氮消毒副产物(nitrogen containing disinfection by-products, N-DBPs)生成势的关系。
长距离调水水源中溶解性有机物特征及消毒副产物生成势的变化解析
Characteristics of dissolved organic matter in the long-distance water diversion source and analysis of changes in disinfection by-products formation potential
-
摘要: 水体中溶解性有机物(dissolved organic matter, DOM)是消毒副产物的重要前体物,本研究考察了季节变化对长距离输水干渠中DOM特征及消毒副产物生成势(disinfection by-products formation potential, DBPsFP)的影响。发现类芳香蛋白和类富里酸是主要荧光类物质,而夏季类可溶性微生物产物组分的比例显著上升,且自生源指标表明夏季样本具有更强的内源特性。体积排阻色谱耦合有机碳检测器(high-performance size exclusion chromatography coupled with an organic carbon detector, HPSEC-OCD)分析显示输水过程中水质稳定,腐殖质(humic substances, HS)组分在总有机碳中所占比例超过60%,而分子质量大于20 kDa的生物大分子聚合体(biopolymers, BP)在夏季有所增加。不同季节DOM的氯反应活性也不同,夏季反应性更强,导致更高的DBPsFP。夏季温度升高,间接促进浮游生物繁殖和微生物活动,进而改变了DOM的组成结构和反应性。此外,由于HPSEC-OCD几乎可以表征所有类型的有机碳,因此它所表征的组分与DBPsFP的相关性更好,其中三卤甲烷生成势与BP组分呈高度正相关,卤乙酸生成势则与HS组分关联更紧密。了解DOM的时空变化特征及其与DBPsFP的相互关系,将有助于更好地优化水处理方法以获得更稳定的水质。Abstract: Dissolved organic matter (DOM) in water bodies serves as a crucial precursor for the formation of disinfection by-products (DBPs). This study investigates the impact of seasonal changes on the characteristics of dissolved organic matter (DOM) and the formation potential of disinfection by-products (DBPsFP) in the trunk canal of the long-distance water transfer. It was found that aromatic protein-like and fulvic acid-like substances are the predominant fluorescent materials, with a significant increase in the proportion of soluble microbial product-like components in the summer, and the biogenic index indicates stronger endogenous characteristics in the summer samples. Analysis using High-Performance Size Exclusion Chromatography coupled with an Organic Carbon Detector (HPSEC-OCD) shows that water quality is stable during the transfer process, with humic substances (HS) accounting for over 60% of the total organic carbon, and an increase in biopolymers (BP) with molecular weights greater than 20 kDa during the summer. The chlorination reactivity of DOM varies with the season, being higher in the summer, which leads to the increased total DBPsFP. The rise in temperature during summer indirectly promotes the proliferation of plankton and microbial activity, thereby altering the composition and reactivity of DOM. Moreover, since HPSEC-OCD can characterize nearly all types of organic carbon, the components it represents correlate better with DBPsFP. Specifically, the formation potential of trihalomethanes shows a high positive correlation with BP components, while the formation potential haloacetic acids is more closely related to HS components. Understanding the spatiotemporal characteristics of DOM and its relationship with DBPsFP will aid in optimizing water treatment methods to achieve more stable water quality.
-
表 1 22种目标DBPs的相关信息
Table 1. Information about 22 target DBPs
消毒副产物 中文名称 英文名称 缩写 卤乙酸
(HAAs)氯乙酸 chloroacetic acid CAA 二氯乙酸 dichloroacetic acid DCAA 三氯乙酸 trichloroacetic acid TCAA 溴乙酸 bromoacetic acid BAA 二溴乙酸 dibromoacetic acid DBAA 溴氯乙酸 bromochloroacetic acid BCAA 三卤甲烷
(THMs)三氯甲烷 trichloromethane TCM 三溴甲烷 tribromomethane TBM 二溴一氯甲烷 dibromochloromethane DBCM 一溴二氯甲烷 bromodichloromethane BDCM 碘代三卤甲烷
(I-THM)三碘甲烷 triiodomethane TIM 卤代酮(HKs) 氯丙酮 chloropropanone CP 1,1,1-三氯丙酮 1,1,1-trichloropropanone 1,1,1-TCP 1,1,3-三氯丙酮 1,1,3-trichloropropanone 1,1,3-TCP 卤代醛
(HALs)二氯乙醛 dichloroacetaldehyde DCAL 三氯乙醛 trichloroacetaldehyde TCAL 卤乙腈
(HANs)三氯乙腈 trichloroacetonitrile TCAN 二氯乙腈 dichloroacetonitrile DCAN 溴乙腈 bromoacetonitrile BAN 二溴乙腈 dibromoacetonitrile DBAN 碘乙腈 iodoacetonitrile IAN 卤乙酰胺(HAM) 二氯乙酰胺 dichloroacetamide DCAM -
[1] HER N, AMY G, MCKNIGHT D, et al. Characterization of DOM as a function of MW by fluorescence EEM and HPLC-SEC using UVA, DOC, and fluorescence detection[J]. Water Research, 2003, 37(17): 4295-4303. doi: 10.1016/S0043-1354(03)00317-8 [2] AVŞAR E, TORÖZ İ. Seasonal determination and investigation of disinfection by product formation potentials (DBPFPs) of surface waters, İstanbul Ömerli and Büyükçekmece case study[J]. Anadolu Ü niversitesi Bilim Ve Teknoloji Dergisi - B Teorik Bilimler, 2018, 6(1): 22-35. [3] AWAD J, VAN LEEUWEN J, CHOW C W K, et al. Seasonal variation in the nature of DOM in a river and drinking water reservoir of a closed catchment[J]. Environmental Pollution, 2017, 220: 788-796. doi: 10.1016/j.envpol.2016.10.054 [4] AVSAR E, TOROZ I, HANEDAR A. Physical characterisation of natural organic matter and determination of disinfection by-product formation potentials in Istanbul surface waters[J]. Fresenius Environmental Bulletin, 2015, 24(9). [5] ZHOU H, TIAN L, NI M, et al. Effect of dissolved organic matter and its fractions on disinfection by-products formation upon karst surface water[J]. Chemosphere, 2022, 308: 136324. doi: 10.1016/j.chemosphere.2022.136324 [6] VILLANUEVA C M, CORDIER S, FONT-RIBERA L, et al. Overview of disinfection by-products and associated health effects[J]. Current Environmental Health Reports, 2015, 2(1): 107-115. doi: 10.1007/s40572-014-0032-x [7] LI X F, MITCH W A. Drinking water disinfection byproducts (DBPs) and human health effects: Multidisciplinary challenges and opportunities[J]. Environmental Science & Technology, 2018, 52(4): 1681-1689. [8] XUE C, YU Y, HUANG X. Comparison of organic matter properties and disinfection by-product formation between the typical groundwater and surface water[J]. Water, 2022, 14(9): 1418. doi: 10.3390/w14091418 [9] BOND T, GOSLAN E H, PARSONS S A, et al. Treatment of disinfection by-product precursors[J]. Environmental Technology, 2011, 32(1): 1-25. doi: 10.1080/09593330.2010.495138 [10] HU C Y, ZHU H Z, LIN Y L, et al. Dissolved organic matter fractions and disinfection by-product formation potential from major raw waters in the water-receiving areas of south-to-north water diversion project, China[J]. Desalination and Water Treatment, 2015, 56(6): 1689-1697. doi: 10.1080/19443994.2014.953211 [11] WANG X, TONG Y, CHANG Q, et al. Source identification and characteristics of dissolved organic matter and disinfection by-product formation potential using EEM-PARAFAC in the Manas River, China[J]. RSC Advances, 2021, 11(46): 28476-28487. doi: 10.1039/D1RA03498G [12] ZHANG J, YU J, AN W, et al. Characterization of disinfection byproduct formation potential in 13 source waters in China[J]. Journal of Environmental Sciences, 2011, 23(2): 183-188. doi: 10.1016/S1001-0742(10)60440-8 [13] MAQBOOL T, LI C, QIN Y, et al. A year-long cyclic pattern of dissolved organic matter in the tap water of a metropolitan city revealed by fluorescence spectroscopy[J]. Science of the Total Environment, 2021, 771: 144850. doi: 10.1016/j.scitotenv.2020.144850 [14] LIU Y, YE Q, HUANG W L, et al. Spectroscopic and molecular-level characteristics of dissolved organic matter in the Pearl River Estuary, South China[J]. Science of the Total Environment, 2020, 710: 136307. doi: 10.1016/j.scitotenv.2019.136307 [15] ZHANG Y, ZHANG N, ZHAO P, et al. Characteristics of molecular weight distribution of dissolved organic matter in bromide-containing water and disinfection by-product formation properties during treatment processes[J]. Journal of Environmental Sciences, 2018, 65: 179-189. doi: 10.1016/j.jes.2017.03.013 [16] RIBAU TEIXEIRA M, ROSA S M, SOUSA V. Natural organic matter and disinfection by-products formation potential in water treatment[J]. Water Resources Management, 2011, 25(12): 3005-3015. doi: 10.1007/s11269-011-9795-0 [17] FERNÁNDEZ-PASCUAL E, DROZ B, O’DWYER J, et al. Fluorescent dissolved organic matter components as surrogates for disinfection byproduct formation in drinking water: A Critical Review[J]. ACS ES& T Water, 2023, 3(8): 1997-2008. [18] MAQBOOL T, QIN Y, LY Q V, et al. Exploring the relative changes in dissolved organic matter for assessing the water quality of full-scale drinking water treatment plants using a fluorescence ratio approach[J]. Water Research, 2020, 183: 116125. doi: 10.1016/j.watres.2020.116125 [19] NONG X, SHAO D, SHANG Y, et al. Analysis of spatio-temporal variation in phytoplankton and its relationship with water quality parameters in the South-to-North Water Diversion Project of China[J]. Environmental Monitoring and Assessment, 2021, 193(9): 593. doi: 10.1007/s10661-021-09391-6 [20] NONG X, SHAO D, ZHONG H, et al. Evaluation of water quality in the South-to-North Water Diversion Project of China using the water quality index (WQI) method[J]. Water Research, 2020, 178: 115781. doi: 10.1016/j.watres.2020.115781 [21] XU Y, LIN J, LEI X, et al. Assessment of the spatiotemporal water quality variations in the Middle Route of China’s South-to-North Water Diversion Project by multivariate analysis[J]. Environmental Science and Pollution Research, 2023, 30(15): 44206-44222. doi: 10.1007/s11356-022-25115-w [22] CHEN W, WESTERHOFF P, LEENHEER J A, et al. Fluorescence excitation−emission matrix regional integration to quantify spectra for dissolved organic matter[J]. Environmental Science & Technology, 2003, 37(24): 5701-5710. [23] 韩港胜, 侯嫔, 储文斌, 等. 水源水Fe(Ⅵ)与Mn(Ⅶ)预氧化对天然有机物的组成特征及消毒副产物生成势的影响[J]. 环境化学, 2023. DOI: 10.7524/j.issn.0254-6108.2022092904. [24] ZUO Y T, CHENG S, JIANG H H, et al. Release and removal of algal organic matter during prechlorination and coagulation treatment of cyanobacteria-laden water: Are we on track?[J]. Science of the Total Environment, 2022, 824: 153793. doi: 10.1016/j.scitotenv.2022.153793 [25] WU S, DONG H, ZHANG L, et al. Formation characteristics and risk assessment of disinfection by-products in drinking water in two of China’s largest basins: Yangtze River basin versus Yellow River basin[J]. ACS ES&T Water, 2023[2023-12-21].https://doi.org/10.1021/acsestwater.3c00355. [26] XU L, HU Q, JIAN M, et al. Exploring the optical properties and molecular characteristics of dissolved organic matter in a large river-connected lake (Poyang Lake, China) using optical spectroscopy and FT-ICR MS analysis[J]. Science of the Total Environment, 2023, 879: 162999. doi: 10.1016/j.scitotenv.2023.162999 [27] 申钊颖, 弓晓峰, 江良, 等. 利用荧光区域积分法解析鄱阳湖DOM组成及来源[J]. 环境科学与技术, 2019, 42(5): 196-203. [28] WANG Z, WU Z. Distribution and transformation of molecular weight of organic matters in membrane bioreactor and conventional activated sludge process[J]. Chemical Engineering Journal, 2009, 150(2-3): 396-402. doi: 10.1016/j.cej.2009.01.018 [29] HUBER S A, BALZ A, ABERT M, et al. Characterisation of aquatic humic and non-humic matter with size-exclusion chromatography – organic carbon detection – organic nitrogen detection (LC-OCD-OND)[J]. Water Research, 2011, 45(2): 879-885. doi: 10.1016/j.watres.2010.09.023 [30] TRAN N H, NGO H H, URASE T, et al. A critical review on characterization strategies of organic matter for wastewater and water treatment processes[J]. Bioresource Technology, 2015, 193: 523-533. doi: 10.1016/j.biortech.2015.06.091 [31] QUANG V L, CHOI I, HUR J. Tracking the behavior of different size fractions of dissolved organic matter in a full-scale advanced drinking water treatment plant[J]. Environmental Science and Pollution Research, 2015, 22(22): 18176-18184. doi: 10.1007/s11356-015-5040-3 [32] KIMURA K, TANAKA K, WATANABE Y. Microfiltration of different surface waters with/without coagulation: Clear correlations between membrane fouling and hydrophilic biopolymers[J]. Water Research, 2014, 49: 434-443. doi: 10.1016/j.watres.2013.10.030 [33] UYAK V, OZDEMIR K, TOROZ I. Seasonal variations of disinfection by-product precursors profile and their removal through surface water treatment plants[J]. Science of the Total Environment, 2008, 390(2/3): 417-424. [34] LI A, ZHAO X, MAO R, et al. Characterization of dissolved organic matter from surface waters with low to high dissolved organic carbon and the related disinfection byproduct formation potential[J]. Journal of Hazardous Materials, 2014, 271: 228-235. doi: 10.1016/j.jhazmat.2014.02.009 [35] NGUYEN H V M, TAK S, HUR J, et al. Fluorescence spectroscopy in the detection and management of disinfection by-product precursors in drinking water treatment processes: A review[J]. Chemosphere, 2023, 343: 140269. doi: 10.1016/j.chemosphere.2023.140269 [36] HUA G, RECKHOW D A. Characterization of disinfection byproduct precursors based on hydrophobicity and molecular size[J]. Environmental Science & Technology, 2007, 41(9): 3309-3315. [37] LIANG L, SINGER P C. Factors influencing the formation and relative distribution of haloacetic acids and trihalomethanes in drinking Water[J]. Environmental Science & Technology, 2003, 37(13): 2920-2928. [38] HUA L C, LIN J L, CHEN P C, et al. Chemical structures of extra- and intra-cellular algogenic organic matters as precursors to the formation of carbonaceous disinfection byproducts[J]. Chemical Engineering Journal, 2017, 328: 1022-1030. doi: 10.1016/j.cej.2017.07.123 [39] HIDAYAH E N, CHOU Y C, YEH H H. Using HPSEC to identify NOM fraction removal and the correlation with disinfection by-product precursors[J]. Water Supply, 2016, 16(2): 305-313. doi: 10.2166/ws.2015.139 [40] WESTERHOFF P, MASH H. Dissolved organic nitrogen in drinking water supplies: a review[J]. Journal of Water Supply:Research and Technology-Aqua, 2002, 51(8): 415-448. doi: 10.2166/aqua.2002.0038 [41] HIDAYAH E N, CHOU Y C, YEH H H. Comparison between HPSEC-OCD and F-EEMs for assessing DBPs formation in water[J]. Journal of Environmental Science and Health, Part A, 2017, 52(4): 391-402. doi: 10.1080/10934529.2016.1262607