title: Concentrations and fluxes of dissolved uranium in the Yellow River estuary: seasonal variation and anthropogenic (Water-Sediment Regulation Scheme) impact.
abstract: The Water-Sediment Regulation Scheme (WSRS) of the Yellow River is a procedure implemented annually from June to July to expel sediments deposited in Xiaolangdi and other large middle-reach reservoirs and to scour the lower reaches of the river, by controlling water and sediment discharges. Dissolved uranium isotopes were measured in river waters collected monthly as well as daily during the 2010 WSRS (June 19-July 16) from Station Lijin (a hydrologic station nearest to the Yellow River estuary). The monthly samples showed dissolved uranium concentrations of 3.85-7.57 μg l(-1) and (234)U/(238)U activity ratios of 1.24-1.53. The concentrations were much higher than those reported for other global major rivers, and showed seasonal variability. Laboratory simulation experiments showed significant uranium release from bottom and suspended sediment. The uranium concentrations and activity ratios differed during the two stages of the WSRS, which may reflect desorption/dissolution of uranium from suspended river sediments of different origins. An annual flux of dissolved uranium of 1.04 × 10(8) g y(-1) was estimated based on the monthly average water discharge and dissolved uranium concentration in the lower reaches of the Yellow River. The amount of dissolved uranium (2.65 × 10(7) g) transported from the Yellow River to the sea during the WSRS constituted about 1/4 of the annual flux.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology (MCTL), Ministry of education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, No. 238, Song Ling Road, Laoshan, Qingdao 266100, PR China.
authors.forename: Sui
authors.initials: S
authors.lastname: Juanjuan
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology (MCTL), Ministry of education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, No. 238, Song Ling Road, Laoshan, Qingdao 266100, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhigang
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology (MCTL), Ministry of education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, No. 238, Song Ling Road, Laoshan, Qingdao 266100, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Bochao
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology (MCTL), Ministry of education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, No. 238, Song Ling Road, Laoshan, Qingdao 266100, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wenhua
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, PR China; Key Laboratory of Marine Environment and ecology, Ministry of education, Ocean University of China, Qingdao 266100, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Dong
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology (MCTL), Ministry of education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, No. 238, Song Ling Road, Laoshan, Qingdao 266100, PR China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Xueyan
mesh_terms: D002681:China; D003247:Conservation of Natural Resources; D063366:Estuaries; D019015:Geologic Sediments / Q000032:analysis*; D011834:Radiation Monitoring; D012621:Seasons; D013057:Spectrum Analysis; D014501:Uranium / Q000032:analysis*; D014872:Water Movements; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D014875:Water Pollutants, Radioactive; D014501:Uranium
keywords: (234)U/(238)U activity ratio; Dissolved uranium; Water-Sediment Regulation Scheme (WSRS); Yellow River