@article{oai:repo.qst.go.jp:00045910,
 author = {Takata, Hyoe and Aono, Tatsuo and Tagami, Keiko and Uchida, Shigeo and 高田 兵衛 and 青野 辰雄 and 田上 恵子 and 内田 滋夫},
 issue = {4},
 journal = {Estuarine, Coastal and Shelf Science},
 month = {Aug},
 note = {Concentrations of cobalt (Co) in surface waters from the Sagami River to northern Sagami Bay and from the Yura River to southwestern Wakasa Bay in Japan were determined in order to investigate the factors governing the distribution of this metal during estuarine mixing. Dissolved (<0.2 um) and particulate (>0.2 um) Co showed non-conservative mixing behavior with low or mid-salinity maxima within those two estuarine regions, indicating benthic remobilization and/or sewage input apart from riverine input during the estuarine mixing. These results are supported by a suite of complementary measurements of other parameters, such as manganese, phosphate, and suspended particulate matter concentrations. In addition, the concentration ratio of dissolved Co to total Co (dissolved plus particulate) increased along the salinity gradient, implying the potential for desorption of this metal from suspended particulate matter on estuarine mixing. To identify desorption of this metal from suspended particulate matter by salinity changes, laboratory desorption experiments were undertaken by mixing unfiltered river water and filtered estuarine water samples with a different volume of each water sample. The mixed water samples for the experiments had different salinity values of 4.0, 17, and 30. Although dissolved Co and particulate Co concentrations at salinity 4.0 were almost constant from 2 min after starting the experiment to 120 h, dissolved Co concentrations at salinities 17 and 30 increased with time in the experimental period. Declines in particulate Co concentrations were observed in those salinities. Also, a relatively high percentage of Co in the solid phase at salinity 30, as compared to the percentage at salinities 4.0 and 17, was desorbed from the particles. Furthermore, these experiments showed the potential for desorption of Co from riverine suspended particulate matter. It is suggested that changes in salinity contributed to the particle-solution exchange of Co. Thus, the combination of benthic remobilization, desorption from suspended particulate matter, and/or sewage input could be responsible for the non-conservative behavior of Co during the estuarine mixing in both estuarine areas.},
 pages = {294--305},
 title = {Processes controlling cobalt distribution in two temperate estuaries, Sagami Bay and Wakasa Bay, Japan},
 volume = {89},
 year = {2010}
}