Pb(II) Removal from Kaolinite by Electrokinetics

Electrochemical processes for in-situ treatment of contaminated soils. Annual progress report, September 1996--May 1997

“…The resulted pH profiles for the 5 tests performed shown in the Figure 4.12 were originated exclusively from the redox reactions of water at the electrodes and demonstrated to have the same pattern as the profiles determined by Hamed et al (1991). The acidic electrolyte solution generated at the anode reservoir flowed across the soil sample lowering the pH to values around 3 to 4 until near to the cathode the pH rose to values about 8 to 9 because of the basic conditions produced by the reduction of water.…”

“…Simultaneously, vigorous production of OH-took place at the cathode because of the electrochemical reduction of water. Accounting for these occurrences, the hydraulic properties of the soil could be altered by dissolution of salts and clay minerals, adsorption/desorption interactions, precipitation of metal hydroxides and cation exchange (Hamed et al, 1991). The complexity of the soil system turned very difficult to interpret the specific causes of the changes of the electrical properties soil core.…”

Electrokinetics and soil decontamination: concepts and overview (Review)

“…A number of important apparatuses that have been used for soil remediation by electrokinetics are mentioned here. The apparatuses currently available for the purpose of electrokinetic remediation include those developed at Louisiana State University [31,79], Lehigh University [52,80,81], University of Texas at Austin [11,82], the University of California at Berkeley [3,83], Massachusetts Institute of Technology [38,47,59], Texas A & M University [6], The Technical University of Denmark [84,85], Vanderbilt University, Nashville, Tennessee [86], Royal Institute of Technology, Stockholm, Sweden [87][88][89], University of South Carolina [58] and many others. A comprehensive review of the apparatus used in the EKD experiments has been presented by Yeung et al [6].…”

“…A comprehensive treatise on removal of Pb (II) from kaolin is reported by Hamed [34] and Hamed et al [79]. The process removed about 75 % to 95 % of Pb (II) at concentrations up to 1500 g g -1 across the test specimen at a energy expenditure of 29-60 kWh m -3 of soil processed.…”

In Situ Measurement of Electro‐Osmotic Fluxes and Conductivity Using Single Wellbore Tracer Tests

“…EO was first explored as a means for de-watering clays for purposes of soil stabilization (Casagrande, 1952). In recent years, the potential of EO for removing contaminants from fine-grained sediments has been explored in both laboratory studies and field scale demonstrations (Hamed et al, 1991;Bruell et al, 1992;Segall and Bruell, 1992;Acar and Alshawabkeh, 1993;Lageman, 1993;Probstein and Hicks, 1993;Shapiro et al, 1993). Recently, the Lasagna™ Project at the Paducah Gaseous Diffusion Plant in Kentucky entailed utilizing EO to transport TCE to activated carbon or iron filing treatment zones within the electric field, resulting in an estimated removal efficiency of 98% in concluded, for example, that the costs associated with EO compare favorably to those of excavation and ex situ treatment in shallow soils, given a sufficient time to accomplish the cleanup.…”