An experimental study of the transport and capture of colloids in a porous medium subjected to step increase in concentration
Elizabeth Rodiera, John Doddsa,*
Laboratoire des Sciences du Genie Chimique, CNRS-ENSIC Nancy I., B.P.451.1 rue Grandville, 54001 Nancy, France
In this study, the transport passage and retention of colloids through porous medium was studied experimentally by Rodier and Dodds. Standard liquid chromatography equipment was utilized to detect the step injection of latex particles which were passed through the bed of glass beads. The fraction of original latex that passed out the columns was investigated as a function of number of pore volume. The role of ionic strength was investigated and compared with DLVO theory.
Ismatec IPN peristaltic pump with a flow rate of 2 ml min-1, glass cheminert chromatographic column with a diameter of 12.7 mm and fill length of 50 mm, Schofell SF 7700 UV wavelength detector, and a Sefram Servotrace recorder, to record the response of UV detection, were used by Rodier and Dodds et al.
In the study carried out by Rodier and Dodds, it was found that the degree of capture (overall) in terms of glass beads surface coverage was always found less than 3% of total surface packing. It means if the surface of glass beads is thought as available to hold latex particles, there will be a very large gap between bed and saturation if the duration of experiment is averagely 3 ? 4 h. The breakthrough point was not delayed corresponding to a single pore volume with different physicochemical conditions. Two sample breakthrough curves are shown below. DLVO theory suggested that the high rates of diffusion at low ionic strengths were attributed to the thickness of electrical double layer.
Aamir Alaud Din