Physical fractionation methods ultrafiltration

The observation that the smaller organic fraction is associated with actinides could have significant applications in the mitigation and cleanup of low-level radioactive contamination in ground and surface waters, in that hollow-fiber ultrafiltration methods could be used to physically concentrate the smaller fractions and remove the actinides 10,21). 

Hollow-fiber ultrafiltration can be a very usefiil tool in obtaining size-fractionated samples for chemical and physical analyses of humic and fulvic acids in surface and groundwaters. The technique is very reproducible because it is strictly a physical separation, it minimizes the potential artifacts associated with the more classical chemical separation techniques. The separation method assumes a spherical structure for the cutoffs and therefore is an empirical approach. Nevertheless, hollow fibers can be used much as 0.45 im filters are used to separate particulate versus dissolved material with a great deal of success. 

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