Early Diagenetic Processes of Redox Sensitive Elements in Yangtze Estuary
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摘要: 通过测试长江口沉积物及间隙水中Fe、Mn、U及Mo的含量,结合早期成岩模型及地球化学热力学分析,探讨了在河口环境中影响间隙水氧化还原敏感元素(Fe、Mn、U及Mo)分布的主要因素.根据Fick第一定律,估算了Fe、Mn、U及Mo在沉积物-水界面的扩散通量.结果表明,间隙水Fe、Mn、U及Mo的含量分别介于0.8~106μmol/L、14.8~258μmol/L、1.9~14.4nmol/L及60~546nmol/L之间.在垂直剖面上,间隙水Fe、Mn峰值分别出现在约5cm或10cm的深度.早期成岩过程是影响长江口沉积物间隙水Fe、Mn分布的主要因素.吸附系数对间隙水Fe、Mn的分布也有重要的影响.吸附系数越高,间隙水Fe、Mn浓度越低.影响间隙水U分布的主要因素为Fe,而Mo与Fe、Mn之间不存在相关性.通量计算结果显示Fe、Mn、U及Mo的扩散通量分别介于3.0~10.5μmol·(m2·d)-1、35.7~439.5μmol·(m2·d)-1、-2.3~0.2nmol·(m2·d)-1及-36.0~94.6nmol·(m2·d)-1之间.沉积物中自生铀组分约占总铀的6%~67%.Abstract: The major factors that govern the vertical distributions of redox sensitive elements (Fe, Mn, U and Mo) in interstitial water are studied by analyzing the measurement of concentrations of Fe, Mn, U and Mo in pore water and sediments in Yangtze estuary, combining with the early diagenesis model and geochemical thermodynamic analysis, The benthic fluxes of Fe, Mn, U and Mo have been calculated according to the Fick's first law. The results show that the concentrations of Fe, Mn, U and Mo in interstitial water in Yangtze Estuary sediments range from 0.8 to 106μmol/L, 14.8 to 258μmol/L, 1.9 to 14.4nmol/L and 60 to 546nmol/L, respectively. The maximum of interstitial Fe2+ and Mn2+ have been observed at 5cm or 10cm in the vertical profiles, respectively. The interstitial iron and manganese profiles are mainly controlled by early diagenetic processes in Yangtze Estuary sediments. Adsorption process has great effect on the distribution of interstitial Fe2+ and Mn2+. The greater the adsorption coefficients are, the less the concentrations of interstitial Fe2+ and Mn2+ are. The vertical distributions of interstitial uranium are mainly controlled by iron. However, there is no correlation between Mo and Fe or Mn. The calculated diffusive fluxes of Fe, Mn, U and Mo range from 3 to 10.5μmol·(m2·d)-1, 35.7 to 439.5μmol·(m2·d)-1, -2.3 to 0.2nmol·(m2·d)-1 and -36 to 94.6nmol·(m2·d)-1, respectively. The ratio of authigenic uranium to total uranium ranges from 6% to 67%.
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Key words:
- redox sensitive elements /
- early diagenesis /
- Yangtze Estuary /
- geochemistry
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表 1 间隙水取样站位及上覆水体化学特征
Table 1. Interstitial water sampling stations and the chemical characteristic of overlying water
站位 经度(°E) 纬度(°N) 水深(m) 上覆水 Fe(μmol·L-1) Mn(μmol·L-1) U(nmol·L-1) Mo(nmol·L-1) pH 619 122.41 30.81 26 0.34 0.18 8.46 79.6 7.82 900 122.57 30.38 20 0.18 0.18 8.03 73.3 7.89 1117 122.69 30.01 24 0.18 0.18 8.82 89.6 7.86 表 2 Slomp模型中应用的固定参数
Table 2. Fixed parameters used in Slomp's model
L1(m) Ds (10-5m2·d-1) Db (10-6m2·d-1) ω (10-5m·d-1) φ Kox (d-1) Ks C0 (μmol·m-3) Ceq (μmol·m-3) 619 1×10-4 2.14 9.96 9.6 0.67 1 1 1.8 40 Mn 900 1×10-4 2.14 9.96 9.6 0.67 1 1 1.8 17 1117 1×10-4 2.14 9.96 9.6 0.67 1 1 1.8 20 619 5×10-3 2.14 9.96 9.6 0.67 10 1 3.4 20 Fe 900 5×10-3 2.14 9.96 9.6 0.67 10 1 2.3 20 1117 5×10-3 2.14 9.96 9.6 0.67 10 1 1.8 5 表 3 Berg模型参数统计
Table 3. Statistical parameters in Berg's model
项目站位 619 900 1117 界面通量(μmol·m-2·d-1) -1.5 -4.6 -33.6 净产生量 1 1.6×10-4 6.6×10-4 4.85×10-3 2 1.0×10-5 -2.0×10-4 -1.45×10-3 3 - 2.0×10-5 -5.00×10-5 ∑ 1.7×10-4 4.8×10-4 3.36×10-2 拟合效果/R2 0.89 0.88 0.99 注:1、2、3是Berg模型自动识别的沉积物带. 表 4 长江河口及其他区域Fe、Mn、U及Mo的扩散通量
Table 4. Diffusion fluxes of Fe, Mn, U and Mo in Yangtze estuary and other areas
站位 Fe (μmol·m-2·d-1) Mn (μmol·m-2·d-1) U (nmol·m-2·d-1) Mo (nmol·m-2·d-1) 文献 619 10.5 35.7 0.2 94.6 本研究 900 3.0 155.3 -1.2 20.8 本研究 1117 6.8 439.5 -2.3 -36.0 本研究 Mexican continental shelf 3.0~86.0 8.7~69.9 a Gotland deep 184.3 6.4 b Hingham bay 30~826 90~2477 c Laurentian trough 21~571 123~3377 d Barbara basin 52~1426 356~9757 e 注:a.引自文献Sawlan and Murray, 1983;b.引自文献 Brugmann et al., 1998 ;c.引自文献Morford et al., 2007 ;d.引自文献Sundby et al., 2004 ;e.引自文献Zheng et al., 2002 .表 5 长江口沉积物自生铀浓度
Table 5. Authigenic uranium concentrations in Yangtze estuary sediments
站位 深度(cm) U自生(μg·g-1) U自生:U总(%) 站位 深度(cm) U自生(μg·g-1) U自生:U总(%) 619 17~18 4.16 38 1117 0~1 1.60 20 20~21 5.17 43 2~3 5.31 44 23~24 8.11 54 4~5 6.41 49 29~30 2.93 29 6~7 107 59 900 12~13 1.35 17 8~9 11.36 63 14~15 1.92 21 10~11 12.38 65 17~18 8.90 56 13~14 14.76 67 20~21 1.69 19 16~17 7.34 52 23~24 52 06 19~20 180 60 26~27 2.66 27 22~23 4.89 41 29~30 76 10 24~25 15.89 69 32~33 4.07 37 30~31 11.87 62 -
[1] Aller, R.C., Hall, P.O.J., Rude, P.D., et al., 1998. Biogeochemical heterogeneity and suboxic diagenesis in hemipelagic sediments of the Panama basin. Deep-Sea Research Part I-Oceanographic Research Papers, 45(1): 133-165. doi: 10.1016/S0967-0637(97)00049-6 [2] Arakaki, T., Morse, J.W., 1993. Coprecipitation and adsorption of Mn(II) with mackinawite (FeS) under conditions similar to those found in anoxic sediments. Geochimica et Cosmochimica Acta, 57(1): 9-14. doi: 10.1016/0016-7037(93)90463-7 [3] Arnason, J.G., Fletcher, B.A., 2003. A 40 year record of Cd, Hg, Pb, and U deposition in sediments of Patroon Reservoir, Albany County, NY, U.S.A. . Environmental Pollution, 123(3): 383-391. doi: 10.1016/S0269-7491(03)00015-0 [4] Bao, G.D., Huang, D.P., Wang, Y.F., 1984. The origin of authigenic pyrite in surface sediments at the Changjiang River mouth and near the shore. Acta Mineralogica Sinica, 4(2): 167-172 (in Chinese with English abstract). [5] Berg, P., Petersen, N.R., Rysgaard, S., 1998. Interpretation of measured concentration profiles in sediment pore water. Limnology and Oceanography, 43(7): 1500-1510. doi: 10.4319/lo.1998.43.7.1500 [6] Boudreau, B.P., 1994. Is burial velocity a master parameter for bioturbation?Geochimica et Cosmochimica Acta, 58(4): 1243-1249. doi: 10.1016/0016-7037(94)90378-6 [7] Boudreau, B.P., 1996. A method-of-lines code for carbon and nutrient diagenesis in aquatic sediments. Computers & Geosciences, 22(5): 479-496. doi: 10.1016/0098-3004(95)00115-8 [8] Boudreau, B.P., 1997. Diagenetic models and their implementation: modelling transport and reactions in aquatic sediments. Springer, Berlin. [9] Brugmann, L., Hallberg, R., Larsson, C., et al., 1998. Trace metal speciation in sea and pore water of the Gotland deep, Baltic Sea, 1994. Applied Geochemistry, 13(3): 359-368. doi: 10.1016/S0883-2927(97)00105-4 [10] Brumsack, H.J., Gieskes, M., 1983. Interstitial water trace-metal chemistry of laminated sediments from the gulf of California, Mexico. Marine Chemistry, 14(1): 89-106. doi: 10.1016/0304-4203(83)90072-5 [11] Canavan, R.W., Van Cappellen, P., Zwolsman, J.J.G., et al., 2007. Geochemistry of trace metals in a fresh water sediment: field results and diagenetic modeling. Science of The Total Environment, 381(1-3): 263-279. doi: 10.1016/j.scitotenv.2007.04.001 [12] Cochran, J.K., Carey, A.E., Sholkovitz, E.R., et al., 1986. The geochemistry of uranium and thorium in coastal marine sediments and sediment pore waters. Geochimica et Cosmochimica Acta, 50(5): 663-680. doi: 10.1016/0016-7037(86)90344-3 [13] Contreras, R., Fogg, T.R., Chasteen, N.D., et al., 1978. Molybdenum in the pore waters of anoxic marine sediments by electron paramagnetic resonance spectroscopy. Marine Chemistry, 6(4): 365-373. doi: 10.1016/0304-4203(78)90017-8 [14] Fernandes, H.M., 1997. Heavy metal distribution in sediments and ecological risk assessment: the role of diagenetic processes in reducing metal toxicity in bottom sediments. Environmental Pollution, 97(3): 317-325. doi: 10.1016/S0269-7491(97)00004-3 [15] Gao, Y., Leermakers, M., Elskens, M., et al., 2007. High resolution profiles of thallium, manganese and iron assessed by DET and DGT techniques in riverine sediment pore waters. The Science of the Total Environment, 373(2-3): 526-533. doi: 10.1016/j.scitotenv.2006.11.047 [16] Haese, R.R., Schramm, J., Rutgers, M.M., et al., 2000. A comparative study of iron and manganese diagenesis in continental slope and deep sea basin sediments off Uruguay (SW Atlantic). International Journal of Earth Sciences, 88(4): 619-629. doi: 10.1007/s005310050292 [17] Helz, G.R., Miller, C.V., Charnock, J.M., et al., 1996. Mechanism of molybdenum removal from the sea and its concentration in black shales: EXAFS evidence. Geochimica et Cosmochimica Acta, 60(19): 3631-3642. doi: 10.1016/0016-7037(96)00195-0 [18] Knox, A.S., Brigmon, R.L., Kaplan, D.I., et al., 2008. Interactions among phosphate amendments, microbes and uranium mobility in contaminated sediments. The Science of The Total Environment, 395(2-3): 63-71. doi: 10.1016/j.scitotenv.2008.01.061 [19] Koshikawa, M.K., Takamatsu, T., Takada, J., et al., 2007. Distributions of dissolved and particulate elements in the Yangtze estuary in 1997-2002: background data before the closure of the Three Gorges dam. Estuarine Coastal and Shelf Science, 71(1-2): 26-36. doi: 10.1016/j.ecss.2006.08.010 [20] Lenhart, J.J., Honeyman, B.D., 1999. Uranium(VI) sorption to hematite in the presence of humic acid. Geochimica et Cosmochimica Acta, 63(19-20): 2891-2901. doi: 10.1016/S0016-7037(99)00269-0 [21] Liu, J.G., Li, A.C., Xu, Z.K., et al., 2007. Manganese Abnormity in Holocene sediments of the Bohai Sea. Journal of China University of Geosciences, 18(2): 135-141. doi: 10.1016/S1002-0705(07)60027-2 [22] Malcolm, S.J., 1985. Early diagenesis of molybdenum in estuarine sediments. Marine Chemistry, 16(3): 213-225. doi: 10.1016/0304-4203(85)90062-3 [23] Martínez-Aguirre, A., Garcice-León, M., Ivanovich, M., 1995. U and Th speciation in river sediments. The Science of the Total Environment, 173-174: 203-209. doi: 10.1016/0048-9697(95)04759-X [24] Morford, J.L., Emerson, S.R., Breckel, E.J., et al., 2005. Diagenesis of oxyanions (V, U, Re, and Mo) in pore waters and sediments from a continental margin. Geochimica et Cosmochimica Acta, 69(21): 5021-5032. doi: 10.1016/j.gca.2005.05.015 [25] Morford, J.L., Martin, W.R., Kalnejais, L.H., et al., 2007. Insights on geochemical cycling of U, Re and Mo from seasonal sampling in Boston Harbor, Massachusetts, USA. Geochimica et Cosmochimica Acta, 71(4): 895-917. doi: 10.1016/j.gca.2006.10.016 [26] Morse, J.W., Eldridge, P.M., 2007. A non-steady state diagenetic model for changes in sediment biogeochemistry in response to seasonally hypoxic/anoxic conditions in the "dead zone" of the Louisiana shelf. Marine Chemistry, 106(1-2): 239-255. doi: 10.1016/j.marchem.2006.02.003 [27] Nagao, S., Nakashima, S., 1992. Possible complexation of uranium with dissolved humic substances in pore water of marine sediments. The Science of The Total Environment, 117-118: 439-447. doi: 10.1016/0048-9697(92)90109-6 [28] Roychoudhury, A.N., 2007. Spatial and seasonal variations in depth profile of trace metals in saltmarsh sediments from Sapelo Island, Georgia, USA. Estuarine Coastal and Shelf Science, 72(4): 675-689. doi: 10.1016/j.ecss.2006.12.003 [29] Sarin, M.M., Church, T.M., 1994. Behaviour of uranium during mixing in the Delaware and Chesapeake estuaries. Estuarine Coastal and Shelf Science, 39(6): 619-631. doi: 10.1016/S0272-7714(06)80013-2 [30] Sawlan, J.J., Murray, J.W., 1983. Trace metal remobilization in the interstitial waters of red clay and hemipelagic marine sediments. Earth and Planetary Science Letters, 64(2): 213-230. doi: 10.1016/0012-821X(83)90205-4 [31] Shaw, T.J., Gieskes, J.M., Jahnke, R.J., 1990. Early diagenesis in differing depositional environments: the response of transition metals in pore water. Geochimica et Cosmochimica Acta, 54(5): 1233-1246. doi: 10.1016/0016-7037(90)90149-F [32] Shaw, T.J., Sholkovitz, E.R., Klinkhammer, G., 1995. Redox dynamics in the Chesapeake Bay: the effect of the sediment/water uranium exchange. Geochimica et Cosmochimica Acta, 58(14): 2985-2993. doi: 10.1016/0016-7037(94)90173-2 [33] Slomp, C.P., Malschaert, J.F.P., Raaphorst, W.V., 1997. Iron and manganese cycling in different sedimentary environments on the North Sea continental margin. Continental Shelf Research, 17(9): 1083-1117. doi: 10.1016/S0278-4343(97)00005-8 [34] Soetaert, K., Herman, P.M.J., Middelburg, J.J., 1996. A model of early diagenetic processes from the shelf to abyssal depths. Geochimica et Cosmochimica Acta, 60(6): 1473-1488. doi: 10.1016/0016-7037(96)00013-0 [35] Song, J.M., Li, P.C., 1996. Iron and manganese in interstitial waters and sediment environments of Nansha Islands, South China Sea. Acta Scientiae Circumstantiae, 16(3): 294-301 (in Chinese with English abstract). [36] Suess, E., 1979. Mineral phases formed in anoxic sediments by microbial decomposition of organic matter. Geochimica et Cosmochimica Acta, 43(3): 339-352. doi: 10.1016/0016-7037(79)90199-6 [37] Sundby, B., Anderson, L.G., Hall Per, O.J., et al., 1986. The effect of oxygen on release and uptake of cobalt, manganese, iron and phosphate at the sediment-water interface. Geochimica et Cosmochimica Acta, 50(6): 1281-1288. doi: 10.1016/0016-7037(86)90411-4 [38] Sundby, B., Martinez, P., Gobeil, C., 2004. Comparative geochemistry of cadmium, rhenium, uranium, and molybdenum in continental margin sediments. Geochimica et Cosmochimica Acta, 68(11): 2485-2493. doi: 10.1016/j.gca.2003.08.011 [39] Swarzenski, P.W., Baskaran, M., 2007. Uranium distribution in the coastal waters and pore waters of Tampa Bay, Florida. Marine Chemistry, 104(1-2): 43-57. doi: 10.1016/j.marchem.2006.05.002 [40] Wang, X.Q., Zheng, L.P., Sun, W.M., 2004. The distribution characteristics of heavy metal elements in the pore water of sediment, Dianshan lake. China Environmental Science, 24(4): 400-404 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZGHJ200404003.htm [41] Wedepohl, K.H., 1995. The composition of the continental crust. Geochimica et Cosmochimica Acta, 59(7): 1217-1232. doi: 10.1016/0016-7037(95)00038-2 [42] Xu, S.M., Zhai, S.K., Zhang, A.B., et al., 2007a. Redox environment effect on the redox sensitive elements in surface sediments from the Yangtze estuary hypoxia zone. Marine Geology & Quaternary Geology, 27(3): 1-8 (in Chinese with English abstract). [43] Xu, S.M., Zhai, S.K., Zhang, A.B., et al., 2007b. Distribution and environment significance of redox sensitive trace elements of the Changjiang estuary hypoxia zone and its contiguous sea area. Acta Sedimentologica Sinica, 25(5): 759-766 (in Chinese with English abstract). [44] Yang, Z.S., Chen, X.H., 2007. Centurial high resolution records of sediment grain-size variation in the mud area off the Changjiang (Yangtze River) estuary and its influencial factors. Quaternary Sciences, 27(5): 690-699 (in Chinese with English abstract). [45] Ye, S.Y., Wu, Q., Zhong S.J., et al., 2006. Pyritization of trace elements in sediments of the Jiaozhou Bay, Qingdao, China. Earth Science—Journal of China University of Geosciences, 31(2): 175-181 (in Chinese with English abstract). [46] Zhao, Y.Y., Yan, M.C., Li, A.C., et al., 2002. Geochemistry of muds along the coast of China and their significance. Geology in China, 29(2): 181-185 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DIZI200202013.htm [47] Zhang, X.D., Zhai, S.K., Xu, S.M., et al., 2005. The "Grain Size Effect" of redox sensitive elements in the sediments in the hypoxia zone of the Changjiang estuary. Periodical of Ocean University of China, 35(5): 868-874 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-QDHY200505033.htm [48] Zheng, Y., Anderson, R.F., Van Geen, A., et al., 2000. Authigenic molybdenum formation in marine sediments: a link to pore water sulfide in the Santa Barbara basin. Geochimica et Cosmochimica Acta, 64(24): 4165-4178. doi: 10.1016/S0016-7037(00)00495-6 [49] Zheng, Y., Anderson, R.F., Van Geen, A., et al., 2002. Preservation of particulate non-lithogenic uranium in marine sediments. Geochimica et Cosmochimica Acta, 66(17): 3085-3092. doi: 10.1016/S0016-7037(01)00632-9 [50] 鲍根德, 黄德佩, 汪依凡, 1984. 长江口邻近陆架表层沉积物中自生黄铁矿的成因探讨. 矿物学报, 4(2): 167-172. doi: 10.3321/j.issn:1000-4734.1984.02.011 [51] 宋金明, 李鹏程, 1996. 南沙群岛海域沉积物环境与间隙水中的铁锰. 环境科学学报, 16(3): 294-301. doi: 10.3321/j.issn:0253-2468.1996.03.007 [52] 王小庆, 郑乐平, 孙为民, 2004. 淀山湖沉积物孔隙水中重金属元素分布特征. 中国环境科学, 24(4): 400-404. doi: 10.3321/j.issn:1000-6923.2004.04.004 [53] 许淑梅, 翟世奎, 张爱滨, 等, 2007a. 长江口外缺氧区沉积物中元素分布的氧化还原环境效应. 海洋地质与第四纪地质, 27(3): 1-8. https://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ200703000.htm [54] 许淑梅, 翟世奎, 张爱滨, 等, 2007b. 长江口及其邻近海域表层沉积物中氧化还原敏感性微量元素的环境指示意义. 沉积学报, 25(5): 759-766. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB200705014.htm [55] 杨作升, 陈晓辉, 2007. 百年来长江口泥质区高分辨率沉积粒度变化及影响因素探讨. 第四纪研究, 27(5): 690-699. doi: 10.3321/j.issn:1001-7410.2007.05.010 [56] 叶思源, 武强, 钟少军, 等, 2006. 青岛胶州湾沉积物痕量元素黄铁矿化程度及其剖面类型. 地球科学——中国地质大学学报, 31(2): 175-181. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200602005.htm [57] 赵一阳, 鄢明才, 李安春, 等, 2002. 中国近海沿岸泥的地球化学特征及其指示意义. 中国地质, 29(2): 181-185. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200202013.htm [58] 张晓东, 翟世奎, 许淑梅, 等, 2005. 长江口外缺氧区沉积物中氧化还原敏感性元素的"粒控效应". 中国海洋大学学报, 35(5): 868-874. https://www.cnki.com.cn/Article/CJFDTOTAL-QDHY200505033.htm