Electro-decontamination of contaminated surfaces

Abstract

A decontaminating system 200 is provided that includes: (a) a decontaminating apparatus 100 including (i) an electrically conductive scrubbing shoe 104 having an inlet 204 for a gel-like material and (ii) an insulating standoff 116 positioned between the scrubbing shoe 104 and a surface 120 to be decontaminated to maintain a desired distance between the scrubbing shoe 104 and the surface 120; (b) a reservoir 216 for the gel-like material 124, the reservoir 216 being in communication with the inlet 204; and (c) a voltage source 224 in communication with the electrically conductive scrubbing shoe 104, whereby a current is passed through the gel-like material 124 applied to the surface 120, thereby removing contaminants from the surface 120.

1 . A method for treating an object, comprising: 
 (a) applying a gel-like material to a surface of the object;    (b) passing a current through the gel-like material on the surface of the object;    (c) curing the gel-like material to form a cured layer of the material; and    (d) removing the cured layer from the object.    
   
   
       2 . The method of  claim 1 , wherein the surface comprises at least one contaminant and wherein, in the passing step (a) the surface of the object is electrolytically stripped of the at least one contaminant.  
   
   
       3 . The method of  claim 1  wherein the gel-like material comprises an electrolytic agent, a latex formulation, and a chelating agent.  
   
   
       4 . The method of  claim 3 , wherein the electrolytic agent is at least one of a halogen and a transition metal.  
   
   
       5 . The method of  claim 4 , wherein the electrolytic agent is a mixture of iodine, iodide and tri-iodide.  
   
   
       6 . The method of  claim 3 , wherein latex formulation comprises a surfactant, initiator, and at least one monomer.  
   
   
       7 . The method of  claim 6 , wherein, in the curing step (c), the initiator is decomposed and causes polymerization of the at least one monomer.  
   
   
       8 . The method of  claim 6 , wherein the at least one monomer is a vinyl monomer and an acrylic monomer.  
   
   
       9 . The method of  claim 3 , wherein the chelating agent is selected from the group consisting of ethylene-diaminetetraacetic acid (EDTA), nitrilotriacetic acid, ethyleneglycol-bis-(β-aminoethyl ether)-N,N-tetraacetic acid, ethylenediamine, porphine, dimercaprol, and mixtures thereof.  
   
   
       10 . The method of  claim 1 , wherein the uncured gel-like material has a viscosity ranging from about 1,000 to about 100,000 cPs and sufficient conductivity to provide current densities at the contaminated surface of from about 0.5 to about 5 amps/inch 2 .  
   
   
       11 . The method of  claim 1 , wherein the cured gel-like material has a tensile strength ranging from about 200 to about 400 psi.  
   
   
       12 . The method of  claim 1 , wherein, in the applying step (a), a layer of the gel-like material is applied to the surface and further comprising after the passing step (b) and before the curing step (c): 
 applying additional gel-like material to the surface, wherein the additional gel-like material is free of electric current before the curing step (c).    
   
   
       13 . The method of  claim 2 , wherein, during the passing step (b), a decontaminating apparatus applies a voltage to the gel-like material and wherein the contaminant is a radioactive isotope.  
   
   
       14 . The method of  claim 13 , wherein the decontaminating apparatus comprises a conductive shoe, a porous and permeable abrasive pad through which the gel-like material is applied to the surface, and an insulating standoff to maintain a selected distance between the conductive shoe and the surface.  
   
   
       15 . The method of  claim 1 , wherein, in the passing step (b), a cyclic voltage waveform is applied to the surface.  
   
   
       16 . A gel-like material for decontaminating a surface, comprising: 
 (a) an electrolytic agent;    (b) a latex formulation; and    (c) a chelating agent.    
   
   
       17 . The gel-like material of  claim 16 , wherein the electrolytic agent is at least one of a halogen and a transition metal.  
   
   
       18 . The gel-like material of  claim 17 , wherein the electrolytic agent is a mixture of iodine, iodide and tri-iodide.  
   
   
       19 . The gel-like material of  claim 16 , wherein latex formulation comprises a surfactant, initiator, and at least one monomer.  
   
   
       20 . The gel-like material of  claim 19 , wherein the at least one monomer is selected from the group consisting of rubbers, esters, nylons, acrylates, acetates, butadienes, acrylonitriles, amides, carbonates, acrylics, vinyls, and mixtures thereof.  
   
   
       21 . The gel-like material of  claim 19 , wherein the at least one monomer is a vinyl monomer and an acrylic monomer.  
   
   
       22 . The gel-like material of  claim 16 , wherein the chelating agent is selected from the group consisting of ethylene-diaminetetraacetic acid (EDTA), nitrilotriacetic acid, ethyleneglycol-bis-(β-aminoethyl ether)-N,N-tetraacetic acid ethylenediamine, porphine, dimercaprol, and mixtures thereof.  
   
   
       23 . The gel-like material of  claim 16 , wherein, before curing, gel-like material has a viscosity ranging from about 1,000 to about 100,000 cPs and sufficient conductivity to provide current densities at the contaminated surface of from about 0.5 to about 5 amps/inch 2 .  
   
   
       24 . The gel-like material of  claim 16 , wherein, after curing, the gel-like material has a tensile strength ranging from about 200 to about 400 psi.  
   
   
       25 . A decontaminating system, comprising: 
 a decontaminating apparatus comprising: 
 an electrically conductive scrubbing shoe having an inlet for a gel-like material; and  
 an insulating standoff positioned between the scrubbing shoe and a surface to be decontaminated to maintain a desired distance between the scrubbing shoe and the surface;  
   a reservoir for the gel-like material, the reservoir being in communication with the inlet; and    a voltage source in communication with the electrically conductive scrubbing shoe, whereby a current is passed through the gel-like material applied to the surface, thereby removing contaminants from the surface.    
   
   
       26 . The decontaminating system of  claim 25 , wherein the decontaminating apparatus further comprises an abrasive pad positioned between the scrubbing shoe and the surface.  
   
   
       27 . The decontaminating system of  claim 26 , wherein the abrasive pad is porous and permeable to permit the gel-like material to pass from the inlet through the pad and onto the surface.  
   
   
       28 . The decontaminating system of  claim 25 , further comprising: 
 a processor and power control module operable to cause the voltage source to apply a cyclic voltage waveform to the shoe.    
   
   
       29 . The decontaminating system of  claim 28 , further comprising: 
 a device for measuring at least one of the voltage applied to the shoe and the current and wherein the processor is operable, based on the measured at least one of the voltage and current, to account for drift in the applied voltage waveform.    
   
   
       30 . The decontaminating system of  claim 25 , further comprising: 
 a memory operable to contain a plurality of differing voltage waveforms for a plurality of differing types of surfaces to be contaminated; and    a processor operable to select a voltage waveform corresponding to a selected type of surface to be contaminated and cause application of the selected voltage waveform to the surface.    
   
   
       31 . The decontaminating system of  claim 25 , wherein the scrubbing shoe comprises a trowell edge to manipulate the gel-like material on the surface.  
   
   
       32 . An arrangement for decontaminating a surface, comprising: 
 a contaminated surface;    a layer of a gel-like material applied to the contaminated surface; and    an electrically conductive surface in contact with a free surface of the gel-like material, the electrically conductive surface being in electrical communication with a power source to pass an electric current through the gel-like material and contaminated surface, wherein the layer is positioned between the contaminated surface and the electrically conductive surface.    
   
   
       33 . The arrangement of  claim 32 , wherein the gel-like material comprises an electrolytic agent, a latex formulation, and a chelating agent.  
   
   
       34 . The arrangement of  claim 33 , wherein the electrolytic agent is at least one of a halogen and a transition metal.  
   
   
       35 . The arrangement of  claim 34 , wherein the electrolytic agent is a mixture of iodine, iodide and tri-iodide.  
   
   
       36 . The arrangement of  claim 34 , wherein latex formulation comprises a surfactant, initiator, and at least one monomer.  
   
   
       37 . The arrangement of  claim 36 , wherein the initiator is decomposed and causes polymerization of at least one monomer.  
   
   
       38 . The arrangement of  claim 36 , wherein the at least one monomer is a vinyl monomer and an acrylic monomer.  
   
   
       39 . The arrangement of  claim 33 , wherein the chelating agent is selected from the group consisting of ethylene-diaminetetraacetic acid (EDTA), nitrilotriacetic acid, ethyleneglycol-bis-(β-aminoethyl ether)-N,N-tetraacetic acid, ethylenediamine, porphine, dimercaprol, and mixtures thereof.  
   
   
       40 . The arrangement of  claim 32 , wherein the uncured gel-like material has a viscosity ranging from about 1,000 to about 100,000 cPs, and sufficient conductivity to provide current densities at the contaminated surface of from about 0.5 to about 5 amps/inch 2 .  
   
   
       41 . The arrangement of  claim 32 , wherein the cured gel-like material has a tensile strength ranging from about 200 to about 400 psi.  
   
   
       42 . The arrangement of  claim 32 , wherein the conductive surface is part of a decontaminating apparatus that comprises a conductive shoe, a porous and permeable abrasive pad through which the gel-like material is applied to the surface, and an insulating standoff to maintain a selected distance between the conductive shoe and the surface and wherein the conductive surface is a surface of the conductive shoe.