干旱区生态环境知识资源中心(Arid): Plutonium Uptake and Behavior In Plants of the Desert Southwest: A Preliminary Assessment.

Arid

报告编号	DE20131017429
	Plutonium Uptake and Behavior In Plants of the Desert Southwest: A Preliminary Assessment.
	Caldwell, E; Duff, M; Ferguson, C.
英文摘要	Eight species of desert vegetation and associated soils were collected from the Nevada National Security Site (N2S2) and analyzed for 238Pu and 239+240Pu concentrations. Amongst the plant species sampled were: atmospheric elemental accumulators (moss and lichen), the very slow growing, long-lived creosote bush and the rapidly growing, short-lived cheatgrass brome. The diversity of growth strategies provided insight into the geochemical behavior and bio-availability of Pu at the N2S2. The highest concentrations of Pu were measured in the onion moss (24.27 Bq kg-1 238Pu and 52.78 Bq kg-1 239+240Pu) followed by the rimmed navel lichen (8.18 Bq kg-1 and 18.4 Bq kg-1 respectively), pointing to the importance of eolian transport of Pu. Brome and desert globemallow accumulated between 3 and 9 times higher concentrations of Pu than creosote and sage brush species. These results support the importance of species specific elemental accumulation strategies rather than exposure duration as the dominant variable influencing Pu concentrations in these plants. Total vegetation elemental concentrations of Ce, Fe, Al, Sm and others were also analyzed. Strong correlations were observed between Fe and Pu. This supports the conclusion that Pu was accumulated as a consequence of the active accumulation of Fe and other plant required nutrients. Cerium and Pu are considered to be chemical analogs. Strong correlations observed in plants support the conclusion that these elements displayed similar geochemical behavior in the environment as it related to the biochemical uptake process of vegetation. Soils were also sampled in association with vegetation samples. This allowed for the calculation of a concentration ratio (CR). The CR values for Pu in plants were highly influenced by the heterogeneity of Pu distribution among sites. Results from the naturally occurring elements of concern were more evenly distributed between sample sites. This allowed for the development of a pattern of plant species that accumulated Ce, Sm, Fe and Al. The highest accumulators of these elements were onion moss, lichen flowed by brome. The lowest accumulators were creosote bush and fourwing saltbush. This ranked order corresponds to plant accumulations of Pu.
英文关键词	Plutonium Deserts Soils Cerium Concentration ration Cresote Distribution Environmental transport Lichens National security Nutrients Plants Sampling Tanks Uptake Vegetation
出版年	2011
语种	英语
国家	United States
URL	http://r.cnki.net/KCMS/detail/detail.aspx?DbCode=KJBG&dbname=KJBGW&filename=59fb144a31c97d1d549eb834
来源机构	Technical Information Center Oak Ridge Tennessee
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/273756
推荐引用方式 GB/T 7714	Caldwell, E,Duff, M,Ferguson, C.. Plutonium Uptake and Behavior In Plants of the Desert Southwest: A Preliminary Assessment.,2011.