Electrosorb process

Based on 1996 testing of the ELECTROSORB process for the U.S. Department of Energy (DOE), the vendor estimates the cost of concrete decontamination to be 4.91/ft. Costs square foot are broken down in the following manner disposal costs 2.51, capital costs 1.15, chemical costs 0.67, labor costs 0.52, vaporization energy 0,033, and electrical costs 0.03. This estimate is based on cleanup of 600 ft and involves the following components ... 

In 1994, Isotron Corporation implemented the Electrosorb process to evaluate the removal of uranium and organic contaminants. 

ISOTRON s ELECTROSORB C technology applies an electric field to induce migration of ionic contaminants from within porous concrete. This process provides an in situ alternative to concrete decontamination, thereby eliminating physical or mechanical damage of the concrete and allowing reuse of the structure or facility. The process generates minimal secondary waste and no airborne particulates common to conventional scabbUng or physical abrasion techniques. 

Chapter 3, by Rolando Guidelli, deals with another aspect of major fundamental interest, the process of electrosorption at electrodes, a topic central to electrochemical surface science Electrosorption Valency and Partial Charge Transfer. Thermodynamic examination of electrochemical adsorption of anions and atomic species, e.g. as in underpotential deposition of H and metal adatoms at noble metals, enables details of the state of polarity of electrosorbed species at metal interfaces to be deduced. The bases and results of studies in this field are treated in depth in this chapter and important relations to surface -potential changes at metals, studied in the gas-phase under high-vacuum conditions, will be recognized. Results obtained in this field of research have significant relevance to behavior of species involved in electrocatalysis, e.g. in fuel-cells, as treated in chapter 4, and in electrodeposition of metals. 

Thermodynamically, it is possible for metallic Mo to be codeposited in a host lattice provided its Gibbs energy is thereby sufficiently lowered. An analogous situation is the deposition of Na into Hg at some 1.2 V less negative than its normal (standard) electrode potential. The extensive coevolution of Hj during Mo electrodeposition with Ni or Co indicates that the overall process of alloy or composite metal deposition is far from efficient and that electrosorbed H may easily also be codeposited into the joint metal lattice, providing a hydride phase. 

Note that in 1968 Wojtowicz et al. were able to directly measure the buildup of OH or O coverage on a Pd electrode in a single oscillatory cycle and correlate it with the periodic process. Moreover, they proposed in their chemical model that the electrosorbed OH (or O), as well as an intermediate product of H.COOH oxidation that is adsorbed at the electrode, are essential for producing oscillations. 

Bai, L. and Conway, B.E. (1993) Three-dimensional impedance spectroscopy diagrams for processes involving electrosorbed intermediates, introducing the third electrode-potential variable—examination of conditions leading to pseudo-inductive behavior. Electrochim. Acta, 38 (14), 1803-1415. 

---