摘要
对青海湖布哈河河口悬浮颗粒物、底部沉积物和青海湖湖底沉积物中的镭(Ra)同位素进行不同盐度和pH值的解吸实验以及扩散实验,得到不同盐度湖水(2.8‰、5.8‰、8.8‰、11.8‰和14.8‰)对悬浮颗粒物中镭的解吸活度,和不同时间段沉积物中镭同位素的扩散速率,探讨盐度、pH值与颗粒物中镭同位素解吸的关系.结果表明,224Ra的解吸活度均高于^(226)Ra和^(228)Ra的解吸活度;在盐度为12‰附近时布哈河河口悬浮颗粒物中223Ra、^(226)Ra和^(228)Ra的解吸程度达到最大值,当盐度<9‰时,^(226)Ra解吸活度大于^(228)Ra,当盐度>9‰时,^(228)Ra的解吸活度大于^(226)Ra,这可能与当地岩石中富铀矿有关.河流沉积物^(226)Ra和^(228)Ra的扩散速率分别是0.039和0.290 dpm/(m^2·h);湖底沉积物^(226)Ra和^(228)Ra的扩散速率分别为0.018和0.092 dpm/(m^2·h),湖底沉积物扩散速率小于河流沉积物扩散速率.
Two laboratory experiments for Radium desorption and diffusion were conducted in this work, which included 1 ） the Radium desorption of sediments that were under different salinities （2.8‰, 5.‰, 8.8‰, 11.8‰ and 14.8‰） from the lake water and the potential of hydrogen from Buha River estuary. 2） Radium diffusive fluxes with time in the overlying water of lake sediments and in river sediments. We have got the desorbed activity of Radium from the suspended particles and Radium diffusion fluxes from surface sediments. The results show that the desorption activities of ^224Ra are higher than those of ^226Ra and ^228Ra, and the desorption degrees of ^224 Ra, ^226Ra and ^228 Ra have reached the maximum value when the salinity near 12‰. The desorption of ^226 Ra activities are greater than that of ^228 Ra when salinity〈9‰, however, when salinity〉9‰, the desorption activities of ^226 Ra is less than that of ^228 Ra, which may be associated with the local rich uranium. The diffusion fluxes of ^226 Ra and ^228 Ra of sediments from Buha River are 0.039 and 0.290 dpm/（ m^2 · h） , respectively, and they are 0.018 and 0.092 dpm/（ m^2·h） from Lake Qinghai, respectively. The Radium diffusion fluxes of sediments in Lake Qinghai are less than that of the river.
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2016年第5期1103-1114,共12页
Journal of Lake Sciences
基金
中国科学院百人计划项目“高原内陆盐湖水环境生物地球化学过程”
中国科学院青海盐湖研究所青年引导基金B类项目
青海省科技厅自然基金项目“大柴旦周围水体中锂的地球化学分布规律及对盐湖补给通量研究”(2016-ZJ-921Q)联合资助
关键词
镭同位素
解吸
扩散
布哈河口
青海湖
Radium isotopes
desorption
diffusion
Buha River estuary
Lake Qinghai
