Abstract
Electrophoresis is an innovative technology to seal leaks in operating surface impoundments that does not require removal of impoundment contents, exposure of workers, or locating the leaks. A suspension of clay particles is added to the impounded liquid. The cathode (negative electrode) is placed inside and the anode (positive electrode) is placed outside the leaking impoundment. An electric field is imposed externally across the geomembrane liner through the leaks. The clay particles migrate to the leaks under the influence of the imposed electric field to form a clay cake seal. This dissertation presents the results of various kinds of laboratory experiments conducted to evaluate the use of an electric field to direct migration of clay particles to a leak, and the hydraulic integrity of the resulting seal. The effects of clay mineralogy, clay particle concentration in suspension, size of leak, electric field strength, and the presence of background metal ions in suspension on migration and cake formation were evaluated. The sealing effectiveness of the resulting clay cakes were evaluated by measuring the hydraulic conductivity, and the internal structures were examined using nuclear magnetic resonance imaging techniques. The effect of the presence of dissolved methanol on the electrophoretic mobility of bentonite was investigated. The results of cake formation experiments indicate that the cake growth rate was dictated by: (1) deposition of clay particles migrated by electrophoresis and gravity; and (21) consolidation of the particles. The cake growth rate and pattern were complex due to continuously changing particle distribution and increasing particle interference with time. The stability of the suspension was a key factor affecting the structural integrity of clay cakes. The dimensions of clay cake increased with increasing electrical energy consumed in system.
Chung, Moonkyung (1995). Sealing impoundment leaks by electrophoresis. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1558501.