Water-sediment distribution and behaviour of Polonium (²¹⁰Po) in a shallow coastal area with high concentration of dissolved organic matters in water, North Vietnam
Main Article Content
Abstract
The behaviour and water-sediment distribution of particle-reactive Polonium-210 in the marine environment with high concentration of total suspended particulates (TSP) and dissolved organic matters (DOC) along the coast of the Tonkin Gulf (North Vietnam) were investigated. It was revealed that the water-sediment distribution coefficient, Kd(s), of 210Po varied from 2.39x103 to 1.9x104 (L kg-1) and from 7x103to 2.5x105 (L kg-1), respectively, in the rainy and dry season. This implies that in the aquatic environment 210Po tends to be of high affinity to suspended particulates. The 210Po Kd(s) was positively correlated with salinity in both rainy and dry seasons. With DOC the Kd(s) was positively correlated in the rainy season, but in the dry season the relationship tended to be reverse. This behaviour of 210Po in the coastal region was explained by the variation of pH of seawater and by the complexation of the isotope with DOC. The Kd(s) found in this study was in an order lower compared to that reported by Malaysian researchers for the Thailand Gulf. The most important source of 210Po was suggested to be from in-situ generation by the decay of its grand-parent 210Pb which mainly derived from the atmospheric fall-out.
Article Details
Keywords
Polonium-210, water-sediment distribution coefficient, coastal region, Tonkin Gulf, Vietnam
References
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[11] G.M. Stewart, J.K. Cochran, J. Xue, C. Lee, S. Wakeham, R.A. Armstrong, P. Masque, J.C. Miquel, “Exploring the connection between Po-210 and organic matter in the northwest Mediterranean”, Deep-Sea Res., 54, 415-427, 2007.
[12] G.M. Stewart, J.K. Cochran, J.C. Miquel, P. Masque, J., Szlosek, A.M. Rodriguez y Baena, S.W. Fowler, B. Gasser, D.J. Hirschberg, “Comparing POC export from 234Th/238U and 210Po/210Pb disequilibria with estimates from sediment traps in the northwest Mediterranean, Deep-Sea Res., 54, 1549-1570, 2007.
[13] G.M. Stewart, S.B. Moran, M.W. Lomas, “Seasonal POC fluxes at BATS estimated from 210Po deficits”, Deep-Sea Res., 57, 113-124, 2010.
[14] E. Verdeny, P. Masque, J. Garcia-Orellana, C. Hanfland, J.K. Cochran, G.M. Stewart, “POC export from ocean surface waters by means of 234Th/238Uand 210Po/210Pb disequilibria: a review of the use of two radiotracer pairs”, Deep-Sea Res., 56, 1502-1518, 2009.
[15] C.L. Wei, S.Y. Lin, D. D.-D. Sheu, W.C. Chou, M.C. Yi, P. H. Santschi and L.S.Wen,“Particle-reactive radionuclides (234Th, 210Pb, 210Po) as tracers for the estimation of export production in the South China Sea”,Biogeosciences 8, 3793–3808, 2011.
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[17] J. Z. Du, J. Zhang, and M. Baskaran, “Application of short-live radionuclides (7Be, 210Pb, 210Po, 137Cs, and 234Th) to trace the sources, transport pathways and deposition particles/sediment in rivers, estuaries and coasts”. In: M. Baskaran (Ed.), “Handbook of environmental isotopes geochemistry (Advances in isotope geochemistry)”, Springer, Hidelberg, 2011.
[18] J.M. Smoak, D.J. DeMaster, S.A. Kuehl, R. H. Pope, B.A.McKee, “The behavior of particle-reactive tracers in a high turbidity environment: 234Th and 210Pb on the Amazon continental shelf”, Geochim.et Cosmochim.Acta, 60(12), 2123-2137, 1996.
[19] S. Tsunogai, Y. Nozaki, ”Lead-210 and polonium-210 in the surface water of the Pacific”, Geochem J., 5(4), 165-73, 1971.
[20] Y. Nozaki, Z. Jing, A. Takeda, “210Pb and 210Po in the equatorial Pacific and the Bering Sea: the effects of biological productivity and boundary scavenging”, Deep-Sea Res., 44(9), 2203-2220, 1997.
[21] G. Benoit, S. D., Oktay-Marshall, A. Cantu, “Partitioning of Cu, Pb, Ag, Zn, Fe, Al and Mn between filter-retained particles, colloids, and solution in six Texas estuaries”,Marine Chem.,45,307–336, 1994.
[22] J. L. Guentzel, R. T. Powell, W. M. Landing andR. P. Mason, “Mercury associated with colloidal material in an estuarine and open ocean”,Marine Chem., 55,177–188, 1996.
[23] S.W. Fowler, “210Po in the marine environment with emphasis on its behaviour within the biosphere”, J. Environ.Radioact., 102, 448-461, 2011.
[24] N. A. B. Saili and C. A. R.Mohamed, “Behavior of 210Po and 210Pb in shallow water region of Mersing estuary, Johor, Malaysia”, Environment Asia 7(2), 7-18, 2014.
[25] T.L. Theng, C.A.R. Mohamed, “Activities of 210Po and 210Pb in the water column at Kuala Selangor, Malaysia”. J.of Environ. Radioact., 80(3), 273-86, 2005.
[26] www.Marintime-Database.com. Retrieved on Feb. 20, 2016
[27] Yolanda Fong-Sam, “The Mineral Industry of Vietnam", U.S. Geological Survey, U.S. Department of the Interior, June 2011, p. 9
[28] Luu Thi Nguyet Minh, Garnier J., Billen G., Orange D., Némery J., Le Thi Phuong Quynh, Tran Hong Thai, Le Lan Anh, “Hydrological regime and water budget of the Red River Delta (Northern Vietnam)”, J. Asian Earth Sci., 37, 219-228, 2010.
[29] MONRE, Vietnamese Ministry of Natural Resources and Environment,“Annual Report on Hydrological Observation in Vietnam for the 1996-2006 time period”, in Vietnamese, Hanoi, 2007.
[30] http://data.worldbank.org/ indicator/AG.CON.FERT.ZS. Retrieved on Feb 20, 2016
[31] ISO 5667-19: 2004: Sampling procedure for the marine environment studies
[32] Dang Duc Nhan, Ngo Quang Huy, Nguyen Hao Quang (Eds.), “Radioactivity measurements applied in the environmental studies”. Publisher of Science and Technique, Hanoi, 284 pp. (in Vietnamese), 2014.
[33] IAEA, International Atomic Energy Agency, “Sediment distribution coefficients and concentration factors for biota in the marine environment”. Technical Report series No.422, IAEA, Vienna, 95 pp, 2004.
[34] E. I. Hamilton, “Radionuclides and Large Particles in Estuarine Sediments”,Marine Poll. Bull., 20(12), 603-607, 1989.
[35] M. Baskaran, P. H. Santcshi, “The role of particles and colloids in the transport of radionuclides in coastal environments of Texas”, Marine Chem., 43, 95-114, 1993.
[36] Chai Yingtao and N. R. Urban,“210Po and 210Pb distributions and residence times in the nearshore region of Lake Superior”, J. Geophys. Res., 109 (2004), C10S07, doi: 10.1029/2003JC002081.
[37] Pham Van Ninh, “Current status of the Environment in Vietnam”. A report to the MONRE, Hanoi, in Vietnamese, (2003).
[38] Y.Chung, T. Wu, “Large 210Po deficiency in the northern South China sea”, Cont. Shelf Res. 25, 1209-1224, 2005.
[39] M.P. Bacon, R.A. Belastock, M. Tecotzky, K.K. Turekian, D.W. Spencer, “Lead-210 and polonium-210 in ocean water profiles of the continental shelf and slope south of New England”, Contin.Shelf Res., 8(5-7), 841-53, 1988.
[40] P.H. Santschi, Y.H. Li, J. Bell, “Natural radionuclides in the water of Narragansett Bay”. Earth and Planet Sci. Lett., 45(1), 201-213, 1979.
[41] Y. Kim, H.S. Yang, “Scavenging of 234Th and 210Po in surface water of Jinhae Bay, Korea during a red tide”, Geochem.J., 38, 505-513, 2004.
[42] M. Baskaran, M. Ravichandran, T.S. Bianchi, “Cycling of 7Be and 210Pb in a high DOC, shallow, turbid estuary of south-east Texas”, Estuar. Coastal Shelf Sci.,45, 165-173, 1997.
[43] J. Hamilton-Taylor, M. Kelly, S. Mudge, K. Bradshaw, “Rapid remobilisation of plutonium from estuarine sediments”, J. Environ.Radioact.,5, 409-415, 1987.
[44] S. Krishnaswami, and D. Lal, “Radionuclide limnochronology”. In A. Lerman (Ed.),“Lakes: Chemistry, Geology, Physics”, Springer-Verlag, New York, pp. 153–178, 1978.
[45] R. C. Aller, L. K. Benninger, and J. K. Cochran, “Tracking particle associated processes in near shore environments by use of 234Th/238U disequilibrium”, Earth Planet. Sci. Lett., 47, 161– 175, 1980.
[46] S. G. Bhat, S. Krishnaswamy, D. Lal, D. Rama, W. S. Moore, “234Th/238U ratios in the ocean”, Earth Planet. Sci. Lett., 5, 483– 491, 1969.
[47] O. Gustafson, P. Gschwend, K. O. Buesseler, “Settling removal rates of PCBs into the northwestern Atlantic derived from 238U-234Th disequilibria”, Environ. Sci. Technol., 31, 3544–3550, 1997.
[48] G. J. Brunskill, and P. Wilkinson, ”Annual supply of 238U, 234U, 230Th, 226Ra, 210Pb, 210Po, and 232Th to Lake 239 (Experimental Lakes Area, Ontario) from terrestrial and atmospheric sources”, Can. J. Fish.Aquat.Sci., 44(Suppl. 1), 215– 230, 1987.
[49] G. Kim, N. Hussain, J. R. Scudlark, T. M. Church, “Excess 210Po in the coastal atmosphere”, Tellus, Ser. B, 52, 74– 80, 2000.
[50] C. R. Olsen, I. L. Larsen, P. D. Lowry, N. H. Cutshall, J. F. Todd, G. T. F. Wong, W. H. Casey, “Atmospheric fluxes and marsh-soil inventories of 7Be and 210Pb”, J. Geophys. Res., 90(20), 10,487–10,495, 1985.
[51] E. R. Christensen, and P. K. Bhunia, “Modeling radiotracers in sediments: Comparison with observations in Lake Huron and Michigan”, J. Geophys. Res., 91(C7), 8559– 9571, 1986.
[52] N. R. Urban, S. J. Eisenreich, D. F. Grigal, K. T. Schurz, “Mobility and diagenesis of Pb and 210Pb in peat”, Geochim.Cosmochim.Acta, 54, 3329– 3346, 1990.
[53] G. Kim, N. Hussain, J. R. Scudlark, T. M. Church, “Factors influencing the atmospheric depositional fluxes of stable Pb, 210Pb, and 7Be into Chesapeake Bay”, J. Atmos. Chem., 36(1), 65– 79, 2000.
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