-
地下水中砷的污染已在世界范围内严重威胁到人体健康,世界卫生组织和我国饮用水卫生标准(GB5749—2022)限值均为10 μg·L−1[1 − 2]. 含砷饮用水被人体长期摄入,会引起以皮肤病变为主的全身性慢性中毒疾病[3 − 4]. 中国大陆高砷地下水分布广泛,在我国高砷地下水主要分布于内蒙古[5 − 6]、湖北[7 − 8]、山西[9 − 11]、新疆[12 − 14]等多个地区. 受地质因素等影响,傍河型地下水是我国北方地区较为普遍的一种饮用水水源地类型,其水质水量受临近河道和地下径流补充双重影响. 海拉尔河沿线傍河型地下水源中砷浓度普遍较高,满洲里地区作为我国最大的口岸城市,长期采用傍河地下水的取水方式[15 − 16],地下水源中砷的健康风险状况广受关注.
地下水含水层中的砷通常会吸附在含氧金属矿物表面,通过微生物参与的氧化还原、竞争吸附和络合反应等特殊的地球化学过程,释放并富集在水体中[17 − 19]. 来自于地下水含水层本身和地表水输入的溶解性有机质(DOM),均可作为重要的能源物质和电子供体,参与地下水中砷的释放[20 − 22]. 据研究报道,DOM作为氧化还原反应中的主要能量提供物质[23],使氧化态的金属离子和砷接受DOM释放的电子,转化成还原态[17]. 而DOM中的有机酸,诸如富里酸和胡里酸均会与三价砷和五价砷竞争地下水矿物质的有效吸附点位,导致含铁矿物表面的砷解吸,从而释放到水体中,尤其在偏酸性环境中,砷的溶解性会增强[24 − 26]. 除此之外,DOM对金属离子和氧化物具有络合作用,可以和金属矿物表面的砷形成可溶解的络合物,促进砷的释放,其中铁、铝、锰等金属离子均可以充当DOM和五价砷的桥联作用物质[27 − 29]. 所以,在高砷地下水的形成过程中,DOM对微生物一系列反应均起到了显著的促进作用.
刘韩等对内蒙古河套平原砷的富集机制进行了较为全面的解析[5]. 满洲里市作为以傍河地下水为饮用水源的特殊地区,其近年来砷浓度升高的原因及其机制还鲜见报道. 本研究通过对满洲里地区地下水取水井及海拉尔河沿线地表水进行DOM三维荧光光谱的测量,基于平行因子分析法对其光谱图进行解译,以期解析地下水中溶解性有机物质的主要类型,探究傍河地下水水井中砷的富集机制及近年地下水砷浓度升高的原因,旨在对海拉尔河沿线地下水取水地区的饮用水安全保障策略的制定提供依据.
海拉尔河典型傍河型地下水源砷的富集机制与溶解性有机物三维荧光特性解析
The enrichment mechanisms of arsenic and three-dimensional fluorescence spectroscopy characteristics of dissolved organic matters in typical riverside groundwater sources of the Hailar River
-
摘要: 傍河型地下水是我国北方地区较为普遍的一种饮用水水源地类型,其水质水量受临近河道和地下径流补充双重影响. 海拉尔河沿线傍河型地下水源中砷浓度较高,备受关注. 溶解性有机质(dissolved organic matter,DOM)是影响地下水中砷释放的主要因素,为此,本研究对海拉尔河和沿线地下水水源中砷(As)的含量和DOM进行调查监测,展开三维荧光光谱分析,利用平行因子法确定水体的有机物组分,对探究砷的富集机理具有重要意义. 结果表明,满洲里水体中DOM包括含陆源类腐殖质(C1)、类醌化合物(C2)和微生物来源的腐殖质(C3)的3种组分. 傍河地下水源的腐殖化程度高于地表河流,且浅水井多为陆源和微生物源混合来源有机物. 有机质通过多种方式影响地下水中砷的浓度,主要为C1通过络合方式促进溶解性砷浓度升高,C2则穿梭于易分解的DOM、Fe和As之间,对微生物的氧化还原作用起传递作用. 综上,在陆源类有机物和微生物利用内源有机碳的共同作用下,使As在地下水中的浓度逐年升高.Abstract: Riverside groundwater is a common type of drinking water source in northern China, and its water quality and quantity are affected by both neighboring river courses and groundwater runoff supplement. Arsenic concentration in riverside groundwater along the Hailar River is high, which has attracted much attention. Dissolved organic matter (DOM) is a key factor of arsenic release in groundwater. This study investigated and monitored the arsenic content and DOM of the Hailar River and groundwater sources along the line, carried out three-dimensional fluorescence spectrum analysis, determined the organic matter composition in water body by parallel factor method, which was of great significance to explore the enrichment mechanism of arsenic. The results showed that the DOM in the water of Manzhouli included three components, C1 was terrestrial humic-like; C2 was semiquinone-like; C3 was microbial humic. The degree of humification in groundwater was relatively higher, and most shallow wells were organic matters of mixed source from terrestrial and microbial sources. Organic matters affect the concentration of As in groundwater in a variety of ways. The main reason was that C1 promoted the increase of soluble arsenic concentration through complexation; and C2 shuttled to enhance microbial oxidation and reduction between DOM, Fe and As. In summary, the concentrations of As in groundwater increased year by year due to the simultaneous use of endogenous organic carbon by terrestrial organisms and microorganisms.
-
表 1 满洲里地表水和地下水主要理化指标和荧光指数
Table 1. Statistics of surface water and groundwater physical-chemistry in the Manzhouli area
样品名称
Sample类型
Water types井深/m
Well depth与海拉尔河距离/m
Distance from
Hailar RiverAs/
(µg·L−1)pH ORP/
mVMn/
(µg·L−1)Fe/
(µg·L−1)DOC/
(mg·L−1)FI HIX BIX GLT 地表水 0 0 4.40 8.69 127.9 120 64.5 3.02 1.63 9.49 0.76 CG 地表水 0 0 3.98 8.93 148.3 88 77.3 3.01 1.58 8.87 0.78 H1 地表水 0 0 4.23 9.05 30.3 45 77.3 3.35 1.58 7.51 0.81 H2 地表水 0 0 4.57 8.67 53.1 56 21.3 2.98 1.61 7.29 0.80 Z1 浅水井 30 2420 19.3 7.11 −93.1 352 30.3 4.12 1.79 15.03 0.80 Z7 浅水井 30 1829 21.5 6.98 −136.1 293 88.8 3.47 1.78 10.71 0.79 Z8 浅水井 30 1536 17.8 7.07 −5.5 464 164 2.97 1.76 11.82 0.77 J16 浅水井 30.3 1039 15.9 7.21 −120.2 711 32.2 5.31 1.79 12.04 0.83 J15 浅水井 31.5 221 18.1 7.21 −129.2 296 36.8 3.48 1.69 12.91 0.76 J24 浅水井 36.9 348 53.3 7.34 −118 204 18.44 3.35 1.79 12.36 0.78 J28 浅水井 39.8 429 44 7.46 −127.9 254 4.47 4.28 1.80 13.37 0.78 J3 浅水井 54 499 32.4 7.31 −129.3 324 14.1 3.82 1.75 14.28 0.75 J4 浅水井 54 751 15.9 7.17 −113.1 679 25.2 3.61 1.75 14.75 0.77 J8 浅水井 38.4 1302 15.9 7.17 −119.7 570 57.1 3.75 1.80 13.16 0.79 J23 深水井 136 899 9.75 7.38 −7.0 119 16.4 4.51 1.87 10.52 0.88 J30 深水井 136 1006 17.7 7.18 −116.4 606 36.7 5.17 1.85 14.15 0.84 -
[1] FENDORF S, MICHAEL H A, van GEEN A. Spatial and temporal variations of groundwater arsenic in South and Southeast Asia[J]. Science, 2010, 328(5982): 1123-1127. doi: 10.1126/science.1172974 [2] 国家市场监督管理总局, 国家标准化管理委员会. 生活饮用水卫生标准: GB 5749—2022[S]. 北京: 中国标准出版社, 2022. State Administration for Market Regulation, Standardization Administration of the People's Republic of China. Standards for drinking water quality: GB 5749—2022[S]. Beijing: Standards Press of China, 2022(in Chinese).
[3] 吴丰昌, 王立英, 黎文, 等. 天然有机质及其在地表环境中的重要性[J]. 湖泊科学, 2008, 20(1): 1-12. doi: 10.18307/2008.0101 WU F C, WANG L Y, LI W, et al. Natural organic matter and its significance in terrestrial surface environment[J]. Journal of Lake Sciences, 2008, 20(1): 1-12 (in Chinese). doi: 10.18307/2008.0101
[4] WANG Y X, PI K F, FENDORF S, et al. Sedimentogenesis and hydrobiogeochemistry of high arsenic Late Pleistocene-Holocene aquifer systems[J]. Earth-Science Reviews, 2019, 189: 79-98. doi: 10.1016/j.earscirev.2017.10.007 [5] 刘韩. 河套平原高砷地下水中异化铁还原菌对砷迁移转化的影响研究[D]. 武汉: 中国地质大学, 2021. LIU H. Arsenic mobilization affected by dissimilatory iron reducing bacteria from high arsenic groundwater in Hetao Basin[D]. Wuhan: China University of Geosciences, 2021 (in Chinese).
[6] 郭华明, 郭琦, 贾永锋, 等. 中国不同区域高砷地下水化学特征及形成过程[J]. 地球科学与环境学报, 2013, 35(3): 83-96. GUO H M, GUO Q, JIA Y F, et al. Chemical characteristics and geochemical processes of high arsenic groundwater in different regions of China[J]. Journal of Earth Sciences and Environment, 2013, 35(3): 83-96 (in Chinese).
[7] 鲁宗杰, 邓娅敏, 杜尧, 等. 江汉平原高砷地下水中DOM三维荧光特征及其指示意义[J]. 地球科学, 2017, 42(5): 771-782. LU Z J, DENG Y M, DU Y, et al. EEMs characteristics of dissolved organic matter and their implication in high arsenic groundwater of Jianghan plain[J]. Earth Science, 2017, 42(5): 771-782 (in Chinese).
[8] 韩莉, 甘义群, 于凯. 江汉平原高砷地下水中溶解性有机质来源的稳定碳同位素示踪研究[J]. 地质学报, 2015, 89(增刊1): 266-268. HAN L, GAN Y Q, YU K. Stable carbon isotope tracing study on the source of dissolved organic matter in high arsenic groundwater in Jianghan plain[J]. Acta Geologica Sinica, 2015, 89(Sup 1): 266-268 (in Chinese).
[9] 梁梦钰, 郭华明, 李晓萌, 等. 贵德盆地三河流域高砷地下水中溶解性有机物三维荧光特性及其指示意义[J]. 地学前缘, 2019, 26(3): 243-254. LIANG M Y, GUO H M, LI X M, et al. Excitation-emission matrix spectroscopic characteristics of dissolved organic matters and the significance in high arsenic groundwater research in the Guide Basin, China[J]. Earth Science Frontiers, 2019, 26(3): 243-254 (in Chinese).
[10] 关林瑞, 钱坤, 李俊霞, 等. 大同盆地地下水系统中碘迁移富集的生物标志物证据[J]. 地质科技情报, 2019, 38(1): 235-242. GUAN L R, QIAN K, LI J X, et al. Mobilization and enrichment of iodine in groundwater from the Datong Basin: Evidences from biomarker study[J]. Geological Science and Technology Information, 2019, 38(1): 235-242 (in Chinese).
[11] 张多, 谢先军, 刘文静, 等. 大同盆地地下水中溶解性有机质分子特征及其对砷迁移富集的影响[J]. 安全与环境工程, 2022, 29(5): 148-154. ZHANG D, XIE X J, LIU W J, et al. Molecular characteristics of dissolved organic matter and its impact on arsenic mobilization and enrichment in groundwater system in Datong Basin[J]. Safety and Environmental Engineering, 2022, 29(5): 148-154 (in Chinese).
[12] 王翔, 罗艳丽, 邓雯文, 等. 新疆奎屯地区高砷地下水DOM三维荧光特征[J]. 中国环境科学, 2020, 40(11): 4974-4981. WANG X, LUO Y L, DENG W W, et al. The 3D-EEM characteristics of DOM in high arsenic groundwater of Kuitun, Xinjiang [J]. China Environmental Science, 2020, 40(11): 4974-4981 (in Chinese).
[13] 王翔. 奎屯河下游区域地下水中砷的释放过程研究[D]. 乌鲁木齐: 新疆农业大学, 2021. WANG X. Mobilization processes of arsenic in groundwater of Kuitun River downsteam[D]. Urumqi: Xinjiang Agricultural University, 2021 (in Chinese).
[14] 袁翰卿, 李巧, 陶洪飞, 等. 新疆奎屯河流域地下水砷富集因素[J]. 环境化学, 2020, 39(2): 524-530. YUAN H Q, LI Q, TAO H F, et al. Groundwater arsenic enrichment factors of Kuitun River Basin, Xinjiang[J]. Environmental Chemistry, 2020, 39(2): 524-530 (in Chinese).
[15] 张坤锋, 昌盛, 付青, 等. 内蒙古东北部地区地下-地表饮用水源多环芳烃污染特征与风险[J]. 环境科学, 2022, 43(6): 3005-3015. ZHANG K F, CHANG S, FU Q, et al. Pollution characteristics and risks of polycyclic aromatic hydrocarbons in underground and surface drinking water sources in northeast Inner Mongolia[J]. Environmental Science, 2022, 43(6): 3005-3015 (in Chinese).
[16] 张坤锋, 赵少延, 孙兴滨, 等. 海拉尔河及傍河地下水饮用水源中挥发性有机物的污染特征与风险[J]. 河南师范大学学报(自然科学版), 2021, 49(5): 74-82. ZHANG K F, ZHAO S Y, SUN X B, et al. Pollution characteristics and risks of volatile organic compounds in drinking water sources of Hailar River and nearby rivers groundwater[J]. Journal of Henan Normal University (Natural Science Edition), 2021, 49(5): 74-82 (in Chinese).
[17] MLADENOV N, ZHENG Y, MILLER M P, et al. Dissolved organic matter sources and consequences for iron and arsenic mobilization in Bangladesh aquifers[J]. Environmental Science & Technology, 2010, 44(1): 123-128. [18] TUFANO K J, FENDORF S. Confounding impacts of iron reduction on arsenic retention[J]. Environmental Science & Technology, 2008, 42(13): 4777-4783. [19] 贾永锋, 郭华明. 高砷地下水研究的热点及发展趋势[J]. 地球科学进展, 2013, 28(1): 51-61. JIA Y F, GUO H M. Hot topics and trends in the study of high arsenic groundwater[J]. Advances in Earth Science, 2013, 28(1): 51-61 (in Chinese).
[20] HARVEY C F, SWARTZ C H, BADRUZZAMAN A B M, et al. Arsenic mobility and groundwater extraction in Bangladesh[J]. Science, 2002, 298(5598): 1602-1606. doi: 10.1126/science.1076978 [21] TUFANO K J, REYES C, SALTIKOV C W, et al. Reductive processes controlling arsenic retention: Revealing the relative importance of iron and arsenic reduction[J]. Environmental Science & Technology, 2008, 42(22): 8283-8289. [22] McARTHUR J M, RAVENSCROFT P, BANERJEE D M, et al. How paleosols influence groundwater flow and arsenic pollution: A model from the Bengal Basin and its worldwide implication[J]. Water Resources Research, 2008, 44(11): W11411. [23] HU X S, ZHOU Y Q, ZHOU L, et al. Urban and agricultural land use regulates the molecular composition and bio-lability of fluvial dissolved organic matter in human-impacted southeastern China[J]. Carbon Research, 2022, 1(1): 19. doi: 10.1007/s44246-022-00020-6 [24] SHARMA P, ROLLE M, KOCAR B, et al. Influence of natural organic matter on As transport and retention[J]. Environmental Science & Technology, 2011, 45(2): 546-553. [25] SAADA A, BREEZE D, CROUZET C, et al. Adsorption of arsenic (V) on kaolinite and on kaolinite-humic acid complexes. Role of humic acid nitrogen groups[J]. Chemosphere, 2003, 51(8): 757-763. doi: 10.1016/S0045-6535(03)00219-4 [26] BOWELL R J. Sorption of arsenic by iron oxides and oxyhydroxides in soils[J]. Applied Geochemistry, 1994, 9(3): 279-286. doi: 10.1016/0883-2927(94)90038-8 [27] REDMAN A D, MACALADY D L, AHMANN D. Natural organic matter affects arsenic speciation and sorption onto hematite[J]. Environmental Science & Technology, 2002, 36(13): 2889-2896. [28] LIN H T, WANG M C, LI G C. Complexation of arsenate with humic substance in water extract of compost[J]. Chemosphere, 2004, 56(11): 1105-1112. doi: 10.1016/j.chemosphere.2004.05.018 [29] 孟永霞, 程艳, 李琳, 等. 匹里青河夏季有色溶解性有机质(CDOM)分布特征及来源分析[J]. 环境化学, 2020, 39(11): 3213-3222. doi: 10.7524/j.issn.0254-6108.2019080902 MENG Y X, CHENG Y, LI L, et al. Distribution characteristics and source analysis of chromophoric dissolved organic matter(CDOM) in Piliqing River in summer[J]. Environmental Chemistry, 2020, 39(11): 3213-3222 (in Chinese). doi: 10.7524/j.issn.0254-6108.2019080902
[30] 严登华, 何岩, 邓伟, 等. 满洲里市水体中氟化物的环境特征[J]. 环境科学研究, 2001, 14(1): 24-26, 30. YAN D H, HE Y, DENG W, et al. The environmental characteristic of fluoride in the water body of Manzhouli city[J]. Research of Environmental Sciences, 2001, 14(1): 24-26, 30 (in Chinese).
[31] 张宝发. 满洲里市水文地质特征[J]. 吉林地质, 2013, 32(3): 77-79, 85. ZHANG B F. Hydrogeological characteristics of Manzhouli[J]. Jilin Geology, 2013, 32(3): 77-79, 85 (in Chinese).
[32] LAVONEN E E, KOTHAWALA D N, TRANVIK L J, et al. Tracking changes in the optical properties and molecular composition of dissolved organic matter during drinking water production[J]. Water Research, 2015, 85: 286-294. doi: 10.1016/j.watres.2015.08.024 [33] OHNO T. Fluorescence inner-filtering correction for determining the humification index of dissolved organic matter[J]. Environmental Science & Technology, 2002, 36(4): 742-746. [34] 张紫薇, 周石磊, 张甜娜, 等. 岗南水库沉积物溶解性有机物光谱时空分布特征及环境意义[J]. 环境科学学报, 2021, 41(9): 3598-3611. ZHANG Z W, ZHOU S L, ZHANG T N, et al. Spatiotemporal evolution and environmental significance of dissolved organic matter (DOM) in sediments of Gangnan Reservoir[J]. Acta Scientiae Circumstantiae, 2021, 41(9): 3598-3611 (in Chinese).
[35] HUGUET A, VACHER L, RELEXANS S, et al. Properties of fluorescent dissolved organic matter in the Gironde Estuary[J]. Organic Geochemistry, 2009, 40(6): 706-719. doi: 10.1016/j.orggeochem.2009.03.002 [36] 鹿帅. 傍河开采驱动下地下水中砷的生物地球化学过程与模拟研究[D]. 长春: 吉林大学, 2018. LU S. Biogeochemical process of arsenic in groundwater and its simulation affected by groundwater exploitation in riverside[D]. Changchun: Jilin University, 2018 (in Chinese).
[37] CORY R M, McKNIGHT D M. Fluorescence spectroscopy reveals ubiquitous presence of oxidized and reduced quinones in dissolved organic matter[J]. Environmental Science & Technology, 2005, 39(21): 8142-8149. [38] STEDMON C A, MARKAGER S, BRO R. Tracing dissolved organic matter in aquatic environments using a new approach to fluorescence spectroscopy[J]. Marine Chemistry, 2003, 82(3/4): 239-254. [39] YAMASHITA Y, KLOEPPEL B D, KNOEPP J, et al. Effects of watershed history on dissolved organic matter characteristics in headwater streams[J]. Ecosystems, 2011, 14(7): 1110-1122. doi: 10.1007/s10021-011-9469-z [40] OSBURN C L, HANDSEL L T, MIKAN M P, et al. Fluorescence tracking of dissolved and particulate organic matter quality in a river-dominated estuary[J]. Environmental Science & Technology, 2012, 46(16): 8628-8636. [41] YAMASHITA Y, TANOUE E. Chemical characterization of protein-like fluorophores in DOM in relation to aromatic amino acids[J]. Marine Chemistry, 2003, 82(3/4): 255-271. [42] 王振. 青海贵德盆地高砷地下水分布和成因探究[D]. 北京: 中国地质大学(北京), 2019. WANG Z. Distribution and genesis mechanism of high arsenic groundwater in the guide basin, Qinghai[D]. Beijing: China University of Geosciences, 2019 (in Chinese).
[43] ISLAM F S, GAULT A G, BOOTHMAN C, et al. Role of metal-reducing bacteria in arsenic release from Bengal delta sediments[J]. Nature, 2004, 430(6995): 68-71. doi: 10.1038/nature02638 [44] 王焰新, 苏春利, 谢先军, 等. 大同盆地地下水砷异常及其成因研究[J]. 中国地质, 2010, 37(3): 771-780. WANG Y X, SU C L, XIE X J, et al. The genesis of high arsenic groundwater: A case study in Datong Basin[J]. Geology in China, 2010, 37(3): 771-780 (in Chinese).
[45] NICKSON R T, McARTHUR J M, RAVENSCROFT P, et al. Mechanism of arsenic release to groundwater, Bangladesh and West Bengal[J]. Applied Geochemistry, 2000, 15(4): 403-413. doi: 10.1016/S0883-2927(99)00086-4 [46] AL LAWATI W M, RIZOULIS A, EICHE E, et al. Characterisation of organic matter and microbial communities in contrasting arsenic-rich Holocene and arsenic-poor Pleistocene aquifers, Red River Delta, Vietnam[J]. Applied Geochemistry, 2012, 27(1): 315-325. doi: 10.1016/j.apgeochem.2011.09.030 [47] POSTMA D, LARSEN F, MINH HUE N T, et al. Arsenic in groundwater of the Red River floodplain, Vietnam: Controlling geochemical processes and reactive transport modeling[J]. Geochimica et Cosmochimica Acta, 2007, 71(21): 5054-5071. doi: 10.1016/j.gca.2007.08.020