排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Bednar AJ Gent DB Gilmore JR Sturgis TC Larson SL 《Journal of environmental quality》2004,33(6):2070-2077
Thorium concentrations at Kirtland Air Force Base training sites in Albuquerque, NM, have been previously described; however, the mechanisms of thorium migration were not fully understood. This work describes the processes affecting thorium mobility in this semiarid soil, which has implications for future remedial action. Aqueous extraction and filtration experiments have demonstrated the colloidal nature of thorium in the soil, due in part to the low solubility of thorium oxide. Colloidal material was defined as that removed by a 0.22-microm or smaller filter after being filtered to nominally dissolved size (0.45 microm). Additionally, association of thorium with natural organic matter is suggested by micro- and ultrafiltration methods, and electrokinetic data, which indicate thorium migration as a negatively charged particle or anionic complex with organic matter. Soil fractionation and digestion experiments show a bimodal distribution of thorium in the largest and smallest size fractions, most likely associated with detrital plant material and inorganic oxide particles, respectively. Plant uptake studies suggest this could also be a mode of thorium migration as plants grown in thorium-containing soil had a higher thorium concentration than those in control soils. Soil erosion laboratory experiments with wind and surface water overflow were performed to determine bulk soil material movement as a possible mechanism of mobility. Information from these experiments is being used to determine viable soil stabilization techniques at the site to maintain a usable training facility with minimal environmental impact. 相似文献
2.
全国个体防护装备标准化技术委员会秘书处 《中国个体防护装备》2006,(4):35-37
个体防护装备国家标准作为国家标准的一个重要组成部分.其制修订工作除了要符合国家的各项规定外,还有其特殊性。现就其具体的工作流程,进行详细的介绍,供个体防护装备科研单位和企业参考。 相似文献
1