Electrochemical remediation

Ibanez JG, Takimoto MM, Vasquez RC, Basak S, Myung N, Rajeshwar K. Laboratory experiments on electrochemical remediation of the environment electrocoagulation of oily wastewater. J Chem Educ 1995 72 1050-1052. 

The first stages of an electrochemical remediation would involve surrounding the contaminated soil with a number of stanchion -type electrodes placed within the soil to a suitable depth, with a central counter-electrode, and applying an electric field between the two types of electrodes. Order-of-magnitude calculations show that currents would have to be passed for several months to remove 90% of the contaminants. Clearly, the soil must be kept wet. 

Ibanez, J. G. Laboratory Experiments on Electrochemical Remediation of the Environment. Part 5 Indirect H2S Remediation, J. Chem. Educ. 2001, 78, 778-779. 

Principles and applications of electrochemical remediation of industrial discharges are presented by Pallav Tatapudi and James M. Fenton. Essentials of direct and indirect oxidation and reduction, membrane processes, electrodialysis, and treatment of gas streams, and of soils, are complemented by discussions of electrode materials, catalysts, and elements of reactor design. 

Electrochemical Remediation Heavy metals and other contaminants can be removed from the soil and groundwater with the help of electrokinetic phenomena (electroosmosis, electrophoresis, electrolysis). In electrochemical remediation processes, a continuous electrical field is generated with electrodes that are inserted into the contaminated soil (Shapiro etal. 1989 Ottosen etal. 1995 Hansen etal. 1997). Laboratory and pilot tests have been conducted, for example, with acetic acid as cleaning solution (Renaud 1990). With elec-... 

The purpose of this book is to provide the state of the art on electrochemical remediation of polluted soils, sediments, and groundwater. Specifically, an... 

Electrochemical Remediation Technologies for Polluted Soils, Sediments and Groundwater, Edited by Krishna R. Reddy and Claudio Cameselle Copyright 2009 John Wiley Sons, Inc. 

A typical field electrochemical remediation system is shown in Rgure 1.1. Initially, weUs/drains are configured and drilled so they surround the contaminated... 

Figure 1.1. Schematic of the implementation of in situ electrochemical remediation systems. The electrodes are inserted into the soil and a direct electric field is applied to the contaminated site, which indnces the transport of the contaminants toward the electrodes. The electrode solntions are pumped, treated, and circulated for contaminant removal. Selected electrode conditioning solutions may be used to induce favorable chemistry at the electrodes and in the soil.

Electrochemical remediation is also referred as electrokinetics, electrokinetic remediation, electroremediation, electroreclamation, and other such terms in the published literature. It should be noted here that when water alone is used at the electrodes, the process is known as unenhanced electrochemical remediation. However, when enhancement strategies (such as using conditioning solutions and ion exchange membranes at the electrodes) are used, then the process is known as enhanced electrochemical remediation. 

Electrochemical remediation has received tremendous attention from environmental professionals because of its unique advantages over other conventional... 

Significant advances have been made toward the understanding of the fundamental processes involved in electrochenucal remediation through controlled and idealized laboratory experiments. Valuable lessons have been learned from a limited number of documented field applications. Nevertheless, numerous research studies have been undertaken recently or ongoing to further understand the processes under field conditions and to develop innovative field systems so that optimized effective electrochemical remediation systems can be implemented at actual field sites. 

The implications of these electrolysis reactions are enormous in that they impact transport, transformation, and degradation processes that control the contaminant migration, removal, and degradation during electrochemical treatment. The different transport, transfer, and transformation processes induced by the applied electric field and how these processes are impacted by the electrolysis reactions at the electrodes are fundamental to the understanding of the electrochemical remediation technologies and are briefly presented in this section. 

When micelles (charged aggregate of molecules or particles) are formed with other species in the processing fluid, or when we deal with slurries, electrophoresis may become significant. Diffusion is an important transport mechanism, but it is a very slow process, so it is estimated to only have a minor influence on contaminant transport during electrochemical remediation. 

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