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溶解性有机物(DOM)是一种重要的地表径流污染物,主要由类富里酸、类腐殖酸和类芳香蛋白物质组成[1],具有活跃的吸附性能,对径流中重金属、PAHs、抗生素和药品等污染物的归趋、毒性和生物利用度起重要影响[2- 3]. 此外,地表径流中稳定存在着大量由无机矿物、有机物及微生物等组成的胶体,同样具有强烈的吸附和迁移性能,可影响径流DOM的环境行为. 有研究发现DOM可以附着在胶体表面并增强胶体稳定性,进一步提高了其迁移能力[4-5]. Aftabtalab等报道DOM会吸附在胶体表面与As形成三元络合物或与As在矿物表面竞争吸附位点影响As的迁移[6]. Yang等发现腐殖酸类DOM存在促进了铀(U(Ⅵ))在金属氧化物胶体悬浮液上的解吸[7]. 因此,探讨地表径流胶体与DOM共迁移行为,对同步控制径流胶体与DOM具有重要意义.
为实现城市径流源头控制目标,下渗设施被广泛应用. 广义的下渗设施兼具滞蓄功能,通过将土壤层换填为粗砂、细砂、砾石等填料层以促进径流快速下渗[8-9]. 研究表明,胶体在多孔介质及裂隙岩石中具有较强的穿透能力,可促进与之结合的其他污染物下渗迁移,使地下环境污染风险增加[10]. 迄今国内外关于城市地表径流胶体与DOM共存时的下渗迁移行为还鲜有报道. 前期,笔者所在研究团队已对DOM污染特性[11]、地表径流胶体污染特性[12]以及径流胶体与DOM结合特性[13]等方面进行了深入研究,发现城市地表径流胶体与DOM之间互相结合干扰,从而影响彼此环境行为.
本文在前期研究基础上,考察城市地表径流胶体与DOM共存时在下渗柱迁移出流浓度变化,分析进水流速、pH值、离子强度和胶体粒径等因素对径流胶体与DOM共迁移行为的影响,旨在为城市地表径流下渗对地下环境的潜在污染风险评价提供理论依据.
城市地表径流胶体与溶解性有机物下渗共迁移行为
Co-migration behavior between colloids and dissolved organic matter from urban surface runoff
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摘要: 针对城市地表径流胶体与溶解性有机物(DOM)共存特性,考察下渗柱中径流胶体和DOM的出流浓度,分析进水流速、pH值、离子强度和胶体粒径变化时城市地表径流胶体与DOM的共下渗迁移行为. 结果表明,径流胶体与DOM结合后,会显著促进对方向下迁移;进水流速越高,径流胶体对DOM 的携带迁移越明显,两者的出流浓度越高;进水流速为10 mL·min−1时,径流胶体和DOM的穿透曲线相对峰值浓度分别比5 mL·min−1时提高了3.5%、8.1%;径流胶体-DOM混合溶液在pH值为6时的下渗共迁移速度最快;Na+存在抑制了径流胶体与DOM的下渗共迁移;共存地表径流胶体粒径越小,DOM的下渗出流时间越早、出流峰值浓度越低.Abstract: Aiming at the coexistence of colloids and dissolved organic matter (DOM) from urban surface runoff, the concentrations of runoff colloids and DOM in effluent from the infiltration column were investigated. Besides, the influence of water flow velocity, pH values, Na+ concentration and particle size of colloids on the co-migration behavior between colloids and dissolved organic matter were analyzed. The results showed that the combination between runoff colloids and DOM significantly promoted their downward migration. The concentrations of runoff colloid and DOM in effluent were much higher when the influent velocity was higher. Compared to the influent velocity of 5 mL·min−1, the relative peak concentrations of the colloids and DOM in effluent were increased by 3.5% and 8.1% under the condition of the influent velocity of 10 mL·min−1, respectively. The co-migration speed of the runoff colloids and DOM was the fastest at pH value of 6. The downward co-migration of runoff colloids and DOM was inhibited by the presence of Na+. The smaller the particle size of coexisting runoff colloids, the earlier the outflow time of DOM and the lower the peak concentration of DOM in effluent.
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Key words:
- runoff /
- colloids /
- dissolved organic matter /
- infiltration /
- co-migration.
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[1] 陈梦瑶, 杜晓丽, 于振亚, 等. 北京市道路雨水径流溶解性有机物化学组分特性 [J]. 环境科学, 2020, 41(4): 1709-1715. CHEN M Y, DU X L, YU Z Y, et al. Characteristics of chemical fractions of dissolved organic matter in road runoff in Beijing [J]. Environmental Science, 2020, 41(4): 1709-1715(in Chinese).
[2] ZHANG Y P, ZHANG B, HE Y L, et al. DOM as an indicator of occurrence and risks of antibiotics in a city-river-reservoir system with multiple pollution sources [J]. Science of the Total Environment, 2019, 686: 276-289. doi: 10.1016/j.scitotenv.2019.05.439 [3] ZHANG Q R, WANG H T, XIA X H, et al. Elevated temperature enhances the bioavailability of pyrene to Daphnia magna in the presence of dissolved organic matter: Implications for the effect of climate warming [J]. Environmental Pollution, 2020, 266: 115349. doi: 10.1016/j.envpol.2020.115349 [4] DU X L, LIANG H, FANG X, et al. Characteristics of colloids and their affinity for heavy metals in road runoff with different traffic in Beijing, China [J]. Environmental Science and Pollution Research, 2021, 28(16): 20082-20092. doi: 10.1007/s11356-020-12020-3 [5] CHEN C, ZHAO K, SHANG J Y, et al. Uranium (VI) transport in saturated heterogeneous media: Influence of kaolinite and humic acid [J]. Environmental Pollution, 2018, 240: 219-226. doi: 10.1016/j.envpol.2018.04.095 [6] AFTABTALAB A, RINKLEBE J, SHAHEEN S M, et al. Review on the interactions of arsenic, iron (oxy)(hydr)oxides, and dissolved organic matter in soils, sediments, and groundwater in a ternary system [J]. Chemosphere, 2022, 286: 131790. doi: 10.1016/j.chemosphere.2021.131790 [7] YANG J W, GE M T, JIN Q, et al. Co-transport of U(VI), humic acid and colloidal gibbsite in water-saturated porous media [J]. Chemosphere, 2019, 231: 405-414. doi: 10.1016/j.chemosphere.2019.05.091 [8] MUTHANNA T M, VIKLANDER M, GJESDAHL N, et al. Heavy metal removal in cold climate bioretention [J]. Water, Air, and Soil Pollution, 2007, 183(1/2/3/4): 391-402. [9] DAVIS A P, HUNT W F, TRAVER R G, et al. Bioretention technology: Overview of current practice and future needs [J]. Journal of Environmental Engineering, 2009, 135(3): 109-117. doi: 10.1061/(ASCE)0733-9372(2009)135:3(109) [10] MAJUMDER S, NATH B, SARKAR S, et al. Size-fractionation of groundwater arsenic in alluvial aquifers of West Bengal, India: The role of organic and inorganic colloids [J]. Science of the Total Environment, 2014, 468/469: 804-812. doi: 10.1016/j.scitotenv.2013.08.087 [11] 于振亚, 杜晓丽, 王蕊, 等. 交通密度对道路雨水径流溶解性有机物污染特性的影响 [J]. 环境科学学报, 2018, 38(2): 528-535. YU Z Y, DU X L, WANG R, et al. Impact of traffic density on dissolved organic matter in road stormwater runoff [J]. Acta Scientiae Circumstantiae, 2018, 38(2): 528-535(in Chinese).
[12] 杜晓丽, 梁卉, 闫鑫瑞, 等. 城市地表径流胶体对重金属下渗迁移行为的影响 [J]. 水资源保护, 2021, 37(1): 118-123,131. DU X L, LIANG H, YAN X R, et al. Effects of urban surface runoff colloid on infiltration and migration behavior of heavy metals [J]. Water Resources Protection, 2021, 37(1): 118-123,131(in Chinese).
[13] 刘殿威, 杜晓丽, 付霄宇, 等. 城市地表径流胶体与溶解性有机物结合特性[J]. 中国环境科学, 2022, 42 (8): 3690-3695. LIU D W, DU X L, FY X Y, et al. Characteristics of the combination between colloids and dissolved organic matter in urban surface runoff. [J]. Chinese Environmental Science , 2022, 42 (8): 3690-3695(in Chinese).
[14] GIMBERT L J, HAYGARTH P M, BECKETT R, et al. Comparison of centrifugation and filtration techniques for the size fractionation of colloidal material in soil suspensions using sedimentation field-flow fractionation [J]. Environmental Science & Technology, 2005, 39(6): 1731-1735. [15] KARATHANASIS A D, JOHNSON D M C. Subsurface transport of Cd, Cr, and Mo mediated by biosolid colloids [J]. Science of the Total Environment, 2006, 354(2/3): 157-169. [16] 朱国胜, 张家发, 陈劲松, 等. 宽级配粗粒土渗透试验尺寸效应及边壁效应研究 [J]. 岩土力学, 2012, 33(9): 2569-2574. ZHU G S, ZHANG J F, CHEN J S, et al. Study of size and wall effects in seepage test of broadly graded coarse materials [J]. Rock and Soil Mechanics, 2012, 33(9): 2569-2574(in Chinese).
[17] 杨亚提, 张平. 离子强度对恒电荷土壤胶体吸附Cu2+和Pb2+ 的影响 [J]. 环境化学, 2001, 20(6): 566-571. LANG Y T, ZHANG Y P. Ionic strength effects on Cu2+, Pb2+ adsorption in constant charge soil colloids [J]. Environmental Chemistry, 2001, 20(6): 566-571(in Chinese).
[18] DEEPTHI RANI R, SASIDHAR P. Sorption of cesium on clay colloids: Kinetic and thermodynamic studies [J]. Aquatic Geochemistry, 2012, 18(4): 281-296. doi: 10.1007/s10498-012-9163-6 [19] 刘毅豪. 城市道路沥青路面融雪剂损害研究[D]. 郑州: 河南大学, 2019. LIU Y H. Study on the damage of snow melting agent to asphalt pavement in urban road[D]. Zhengzhou: Henan University, 2019(in Chinese).
[20] 梁卉. 城市地表径流胶体与重金属协同污染及下渗迁移行为研究[D]. 北京: 北京建筑大学, 2020. LIANG H. Study on pollution characteristics of colloids and their affinity for heavy metals in road runoff and co-transport behavior[D]. Beijing: Beijing University of Civil Engineering and Architecture, 2020(in Chinese).
[21] AIKEN G R, HSU-KIM H, RYAN J N. Influence of dissolved organic matter on the environmental fate of metals, nanoparticles, and colloids [J]. Environmental Science & Technology, 2011, 45(8): 3196-3201. [22] AMAL R, RAPER J A, WAITE T D. Effect of fulvic acid adsorption on the aggregation kinetics and structure of hematite particles [J]. Journal of Colloid and Interface Science, 1992, 151(1): 244-257. doi: 10.1016/0021-9797(92)90255-K [23] LEE S A, FANE A G, WAITE T D. Impact of natural organic matter on floc size and structure effects in membrane filtration [J]. Environmental Science & Technology, 2005, 39(17): 6477-6486. [24] TANG X Y, WEISBROD N. Colloid-facilitated transport of lead in natural discrete fractures [J]. Environmental Pollution, 2009, 157(8/9): 2266-2274. [25] 侯培强, 任玉芬, 王效科, 等. 北京市城市降雨径流水质评价研究 [J]. 环境科学, 2012, 33(1): 71-75. HOU P Q, REN Y F, WANG X K, et al. Research on evaluation of water quality of Beijing urban stormwater runoff [J]. Environmental Science, 2012, 33(1): 71-75(in Chinese).
[26] SUN Y L, PAN D Q, WEI X Y, et al. Insight into the stability and correlated transport of kaolinite colloid: Effect of pH, electrolytes and humic substances [J]. Environmental Pollution, 2020, 266: 115189. doi: 10.1016/j.envpol.2020.115189 [27] AMIRBAHMAN A, OLSON T M. Deposition kinetics of humic matter-coated hematite in porous media in the presence of Ca2+ [J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 1995, 99(1): 1-10. [28] CHEN K L, ELIMELECH M. Influence of humic acid on the aggregation kinetics of fullerene (C60) nanoparticles in monovalent and divalent electrolyte solutions [J]. Journal of Colloid and Interface Science, 2007, 309(1): 126-134. doi: 10.1016/j.jcis.2007.01.074