Humic colloids

Evidence for the association of U with humic acids has been documented elsewhere. Dearlove et al. (1991) showed that U concentrated by ultrafiltration techniques from organic-rich groundwater samples were associated with humic colloids. Humic and fulvic acids have been shown to strongly complex U. Lienert et al. (1994) modeled the distribution of U species in the Glatt River and concluded that U-humate complexes become important at pH <6.8. These results reinforce the conclusions in the estuarine studies that U humate and fulvate complexes may account for the association of U with colloids. 

Interactions of Enzymes with Soil Mineral and Humic Colloids... 

Extracellular enzymes are rapidly sorbed at mineral and humic colloids in soils and sediments. Mineral colloids have a high affinity for enzymes although that is not always synonymous with the retention of their catalytic ability. On the other hand, humic substances have the ability to sorb and sequester enzymes in such a way as to retain their catalytic activity they could also strongly inactivate enzyme activity depending on interaction mechanisms. 

Artinger, R Rabung, Th. et al. 2002. Humic colloid-borne migration of uranium in sand columns. Journal of Contaminant Hydrology, 58, 1-12. 

Artinger, R., Buckau, G., Zeh, P., Geraedts, K., Vancluysen, I, Maes, A. Kim, J. I. 2003. Humic colloid mediated transport of tetravalent actinides and technetium. Radiochimica Acta, 91, 743-750. 

Buckau, G., Artinger, R., Fritz, P., Geyer, S., Kim, J. I. Wolf, M. 2000. Origin and mobility of humic colloids in the Gorleben aquifer system. Applied Geochemistry, 15, 183-191. 

Geckeis, H., Rabung, Th., Ngo Manh, Th., Kim, J. I. Beck, H. P. 2002. Humic colloid-borne natural polyvalent metal ions Dissociation experiment. Environmental Science and Technology, 36, 2946-2952. 

Schuessler, W., Artinger, R., Kienzler, B. KlM, J. I. 2000. Conceptual modeling of the humic colloid-borne americium(III) migration by a kinetic approach. Environmental Science and Technology, 34, 2608-2611. 

Guetzloff,T. F., and Rice, J. A. (1996). Micellar nature of humic colloids. In Humic and Fulvic Acids Isolation, Structure, and Environmental Role, Gaffney, S., Marley, A., and Clark, S. B., eds., ACS Symposium Series, No. 651, American Chemical Society, Washington, D.C., pp. 18-25. 

Thang, N.M. et al., Application of the flow field flow fractionation (FFFF) to the characterization of aquatic humic colloids evaluation and optimization of the method, Colloids Surfaces, 181, 289, 2001. 

Several studies have shown that actinide-humic acid complexes are thermodynamically stable in high-ionic-strength solutions (Czerwinski et al, 1996 Marquardt et al., 1996 Labonne-Wall et al, 1999). However, destabilization of humic colloids at high ionic strength (Buckau et al, 2000) and competition for humic... 

The area has been forested especially with pine and spruce and there is much less of agricultural land today. The humic material from the peat bogs will cause increased humic concentrations in the lake. Radionuclides can be associated with humic colloids and even radionuclides such as plutonium may be transported long distances. 

Sorption to Organic Colloids Colloidal organic material (e.g., humic colloids) absorbs nonpolar organic chemicals. Operationally, an increase of ap-... 

Isotopic Characterization of Humic Colloids and Other Organic and Inorganic Dissolved Species in Selected Groundwaters from Sand Aqnifers at Gorleben, Germany... 

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