Treatment of contaminated liquids

Abstract

Contaminants are removed from a quantity of contaminated liquid in a treatment reservoir ( 2,28 ) containing a carbon based adsorbent material capable of electrochemical regeneration. The adsorbent material is in the form of a bed supported on a plate ( 6 ) at the base of the reservoir. The bed is agitated for a period to distribute the adsorbent material in the liquid and adsorb contaminant therefrom. At the end of the period the agitation ceases, and the bed of adsorbent material is allowed to settle. The adsorbent is then regenerated, during or after settlement, by passing an electric current through the bed to release from the adsorbent gaseous products derived from the contaminant, in bubbles rising through the decontaminated liquid in the reservoir. Various methods of regenerating the adsorbent material are disclosed, as are apparatus in which the method can be applied.

1 - 8 . (canceled) 
     
     
         9 . A method of removing contaminants from a contaminated gas, comprising:
 delivering a liquid to a treatment reservoir containing a carbon-based adsorbent material capable of electrochemical regeneration in the form of a bed of particles at the base of the reservoir;   delivering the contaminated gas to the bed of adsorbent material to agitate the bed and distribute the adsorbent material in the liquid and adsorb contaminant from the contaminated gas, and releasing the decontaminated gas;   ceasing the agitation, and allowing the bed of material to settle; and   regenerating the adsorbent by passing an electric current through the bed to release from the adsorbent gaseous products derived from the contaminant in bubbles rising through the liquid in the reservoir.   
     
     
         10 . A method according to  claim 9  including the preliminary step of
 installing in the base of the reservoir a distributor for the fluid, on which distributor the bed of adsorbent is formed, the distributor being coupled to a source of fluid for delivery thereto. 
 
     
     
         11 . A method according to  claim 9  wherein at least some of the contaminated gas dissolves in the liquid 
     
     
         12 . A method according to  claim 11  wherein the liquid is substantially decontaminated in a method comprising: delivering the liquid to a treatment reservoir containing a carbon-based adsorbent material capable of electrochemical regeneration in the form of a bed of particles at the base of the reservoir; agitating the bed to distribute the adsorbent material in the liquid and adsorb contaminant therefrom; ceasing the agitation, and allowing the bed of material to settle; regenerating the adsorbent by passing an electric current through the bed to release from the adsorbent gaseous products derived from the contaminant in bubbles rising through the liquid in the reservoir; and removing the decontaminated liquid from the tank. 
     
     
         13 . A method according to  claim 9  wherein the adsorbent material comprises unexpanded intercalated graphite. 
     
     
         14 . A method according to  claim 9  wherein the adsorbent material is in the form of a powder or flakes. 
     
     
         15 . A method according to  claim 9  wherein the reservoir comprises an upper section for receiving liquid to be treated and a lower section for housing the bed of adsorbent, the cross-section of the lower section being less than that of the upper section, and wherein the bed of adsorbent material re-forms in the lower section to be regenerated. 
     
     
         16 . A method according to  claim 9  wherein the bed of adsorbent material has a substantially square or rectangular horizontal cross-section, and the electric current is passed between electrodes disposed on opposite sides of the bed. 
     
     
         17 . A method according to  claim 9  wherein liquid in the reservoir is mechanically agitated. 
     
     
         18 . Apparatus for the treatment of a liquid to remove contaminants therefrom, comprising a reservoir for the liquid having an upper and a lower section, and containing adsorbent material capable of electrochemical regeneration in the form of a bed of particles supported in the lower section at the base of the reservoir; an agitator for agitating the bed to distribute the particles in liquid contained in the reservoir including the upper section; and electrodes on opposite sides of the lower section for delivering electric current to pass through the bed of particles. 
     
     
         19 . Apparatus according to  claim 18  wherein the agitator comprises a chamber under the bed with discharge orifices directed therefrom upwards into the bed, and means for delivering fluid under pressure through the orifices into the bed to distribute the bed particles. 
     
     
         20 . Apparatus according to  claim 18  wherein the agitator comprises a plurality of nozzles for directing fluid under pressure upwards into the bed to distribute the bed particles. 
     
     
         21 . Apparatus according to  claim 19  wherein the agitator is connected to a source of said fluid under pressure. 
     
     
         22 . Apparatus according to  claim 19  wherein said fluid is selected from the group consisting of a liquid and a gas. 
     
     
         23 . (canceled) 
     
     
         24 . Apparatus according to  claim 22  wherein the gas is air. 
     
     
         25 . Apparatus according to  claim 18  wherein the agitator is removably mounted in the reservoir. 
     
     
         26 . Apparatus according to  claim 18  wherein at least the lower section of the reservoir has a square or rectangular horizontal cross-section. 
     
     
         27 . Apparatus according to  claim 18  wherein the horizontal cross-section of the lower reservoir section is less than that of the upper section. 
     
     
         28 . Apparatus according to  claim 18  wherein a plurality of electrodes are disposed on each of two opposite sides of the reservoir lower section. 
     
     
         29 . Apparatus according to  claim 18  including a mechanical agitator in the reservoir upper section.