A New Two-dimensional Laboratory Apparatus for Electrokinetic Extraction

Abstract

In this paper, the design, fabrication and assembly of a new two-dimensional (2-d) apparatus for electrokinetic extraction studies are presented in detail. The apparatus was designed to simulate the field electrokinetic soil decontamination process to better understand the various contaminant transport processes, electrochemical reactions, and physicochemical soil-contaminant interactions. The apparatus consists of an electrokinetic extraction apparatus and a consolidation apparatus. The distinct advantages of the new 2-d apparatus are: (1) it is capable of applying a nonuniform electric field across the soil specimen to better simulate the field electrokinetic extraction process; (2) it is very simple to assemble, operate, and monitor most of the important parameters controlling the extraction efficiency during the electrokinetic extraction process; (3) the electrical voltage distribution can be monitored as a function of time and space; and (4) soil samples at different locations of the specimen can be easily collected for chemical analyses after electrokinetic extraction. The results of a typical electrokinetic extraction experiment obtained by the new apparatus on a remolded natural clay specimen were reported to demonstrate the operation of the apparatus and to illustrate the various parameters measured at different spatial and temporal intervals during electrokinetic extraction.