黄茅海—广海湾及其邻近海域表层沉积物中γ放射性核素含量水平  

Radionuclides in surface sediments from the Huangmaohai Estuary?Guanghai Bay and its adjacent sea area of the South China Sea

作　　者：赵峰[1] 吴梅桂[1] 周鹏[1] 李冬梅[1] 赵力[1] 郑远来[1] 蔡伟叙[1] 方宏达[1] 黄楚光[1] 

机构地区：[1]国家海洋局南海环境监测中心,广东广州510300

出　　处：《热带海洋学报》2015年第4期77-82,共6页Journal of Tropical Oceanography

基　　金：国家海洋局南海分局海洋科学技术局长基金项目资助(1332;1333)

摘　　要：用HPGe-γ谱分析方法测定了黄茅海—广海湾及邻近海域表层沉积物中238U、226Ra、210Pb、228Th、228Ra、40K和137Cs核素,其放射性比活度范围分别为66.5~98.8、32.0~48.7、96.2~174.7、57.7~101.0、49.7~64.8、505~644和0.72~2.15Bq·kg DW–1,平均值为77.4、36.6、123.8、64.5、58.1、571和1.52Bq·kg DW–1。沉积物中226Ra/238U、210Pb/226Ra和228Th/228Ra比值的范围分别为0.42~0.50、2.80~4.09和1.06~1.66,平均值为0.47、3.38和1.20。结果显示,该海域表层沉积物中天然210Pb相对于226Ra过剩,228Th相对于228Ra过剩,226Ra相对于238U缺损;γ放射性核素含量与沉积物的粒度分布、离岸距离无明显相关性。Radionuclides in the surface sediments from Huangmaohai Esturary-Guanghai Bay and its adjacent sea area of the South China Sea were measured using HPGe-γ spectroscopy. The specific activities of 238U, 226Ra, 210pb, 228Th, 228Ra, 40K, and 137Cs were 66.50~98.80, 32~48.70, 96.20~174.70, 57.70~101.00, 49.70~64.80, 505~644, and 0.72~2.15 Bq·kgDW-1, with the mean values of 77.40, 36.60, 123.80, 64.50, 58.10, 571, and 1.52 Bq·kgDW-1, respectively. The ratios of 226Ra/238U, 210pb/226Ra and 228Th/228Ra were 0.42~0.50, 2.80~4.09 and 1.06~1.66, with the average values of 0.47, 3.38 and 1.20, respectively. It was shown that the uranium and thorium decay series were in disequilibrium in the surface sediments, where 210Pb relative of 226Ra and 228Ra relative of 22SRa were excess while 226Ra relative of 238U was deficient. The distances from the sampling site to the coast were not interrelated with 7 radionuclides contents and grain-size characteristics of the surface sediments.

关 键 词：放射性核素 Γ能谱 表层沉积物 黄茅海 广海湾 

分 类 号：P736.45[天文地球—海洋地质]