Particle dynamics of 7Be, 210Pb and the implications of sedimentation of heavy metals in the Wenjiao/Wenchang and Wanquan River estuaries, Hainan, China
Particle dynamics of 7Be, 210Pb and the implications of sedimentation of heavy metals in the Wenjiao/Wenchang and Wanquan River estuaries, Hainan, China
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DOI：
10.1016/j.ecss.2011.05.013
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发表时间：
2011-07-20
影响因子：
2.8
通讯作者：
Zhang, Jing
中科院分区：
文献类型：
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作者：
Huang, Dekun;Du, Jinzhou;Zhang, Jing
放射性核素（即，Be-7和Pb-210）可用于追踪颗粒和沉积物动力学，并量化时间尺度从几天到一百年的沿海海洋过程。本文通过对文昌河和万泉河河口悬浮颗粒物中Be-7和Pb-210核素的测定，研究了文昌河和万泉河河口悬浮颗粒物的沉降动力学及其沉积重金属的指示意义。在温郊/文昌河口，颗粒相的Be-7和过量Pb-210（Pb-210（xs））的活度范围分别为2.1-54.5和4.6-67.9 Bq kg（-1）。在万泉河河口，Be-7的活度范围为1.2-43.5 Bq kg（-1），Pb-210的活度范围为6.2-194.5 Bq kg（-1）（xs）。同时，溶解相的Be-7和Pb-210的活度范围分别为0.46-1.26和0.30-1.17 Bq m（-3），在温郊/文昌河口; Be-7和Pb-210的活度范围分别为0.10-2.31和0.09-1.87 Bq m（-3），在万泉河河口。在万泉河河口，随着悬浮颗粒物（SPM）浓度和/或盐度的增加，两种核素的分配系数（Kd）均呈下降趋势。Be-7和Pb-210（xs）在温郊/文昌河口的停留时间分别为0.4-1.6和1.65-5.15 d，在万泉河河口的停留时间分别为0.02 - 3.2和0.61-4.44 d。两种核素的所有停留时间在向海方向增加。结果表明，在温郊/文昌河口，有11.8 - 21.0%的Cu、3.0-9.0%的Zn和43.2-69.9%的Cd从水体中迁移并沉积到河口中;在万泉河河口，有24.2-34.8%的Cu、7.2-23.8%的Zn和70.0-82.5%的Cd从水体中迁移并沉积到河口中。(C)2011爱思唯尔有限公司保留所有权利。
Radionuclides (i.e., Be-7 and Pb-210) can be used to trace particle and sediment dynamics and to quantify coastal oceanic processes with time scales ranging from a few days to a hundred years. Here, we study the settling dynamics of suspended particles and the implication by sedimentary heavy metals in the Wenjiao/Wenchang River and Wanquan River estuaries through the measurement of the particulate Be-7 and Pb-210 nuclides. Activity in the particulate phase had a range of 2.1-54.5 and 4.6-67.9 Bq kg(-1) for Be-7 and excess Pb-210 (Pb-210(xs)), respectively, in the Wenjiao/Wenchang River estuary. In the Wanquan River estuary, activity is in the range of 1.2-43.5 Bq kg(-1) for Be-7 and 6.2-194.5 Bq kg(-1) for Pb-210(xs). At the same time, activity in the dissolved phase had a range of 0.46-1.26 and 0.30-1.17 Bq m(-3) for Be-7 and Pb-210, respectively, in the Wenjiao/Wenchang River estuary; ranges of 0.10-2.31 and 0.09-1.87 Bq m(-3) for Be-7 and Pb-210, respectively, were observed in the Wanquan River estuary. The distribution coefficients (K-d) for the two nuclides decreased within increased in suspended particle matters (SPM) concentration and/or salinity in Wanquan River estuary. The residence times of particulate Be-7 and Pb-210(xs) had ranges of 0.4-1.6 and 1.65-5.15 days, respectively, in the Wenjiao/Wenchang River estuary; and ranges of 0.02 -3.2 and 0.61-4.44 days, respectively in the Wanquan River estuary. All residence times for the two nuclides increased in the seaward direction. In the Wenjiao/Wenchang River estuary, we found that 11.8 -21.0% of Cu, 3.0-9.0% of Zn and 43.2-69.9% for Cd is removed from the water column and deposited into the estuary, and 24.2-34.8% for Cu, 7.2-23.8% for Zn, and 70.0-82.5% for Cd in the Wanquan River estuary, respectively. (C) 2011 Elsevier Ltd. All rights reserved.