Methods and systems for reduction of halogenated compounds

Abstract

Methods and systems for dehalogenating organohalides are disclosed. In one respect, the systems can generate hydrogen in an electrolysis cell and supply the hydrogen to anaerobic dehalogenating bacteria to decontaminate organohalides at a contamination site.

1 . (canceled) 
     
     
         2 . A method of dehalogenating organohalides, comprising:
 providing organic-containing wastewater to anode-respiring bacteria coupled to an anode;   generating electrons in the anode;   transporting electrons to a cathode;   providing electrons to hydrogen ions at the cathode;   generating hydrogen molecules;   providing hydrogen molecules to anaerobic dehalogenating bacteria at a contamination site, where the contamination site is contaminated with organohalides; and   dehalogenating the organohalides.   
     
     
         3 . The method of  claim 2 , further comprising detecting anaerobic dehalogenating bacteria at the contamination site. 
     
     
         4 . The method of  claim 2 , further comprising providing anaerobic dehalogenating bacteria to the contamination site. 
     
     
         5 - 8 . (canceled) 
     
     
         9 . A system for dehalogenating organohalides, comprising:
 an electrolysis cell, the electrolysis cell being configured to generate hydrogen; a contamination site, where the contamination site is contaminated with chlorinated solvents:   anaerobic dehalogenating bacteria;   a distribution mechanism configured to distribute the hydrogen to the anaerobic dehalogenating bacteria;   where the electrolysis cell comprises:   a power supply;   an anode chamber containing an anode, the anode being coupled to the power supply;   anode-respiring bacteria coupled to the anode; and   a cathode chamber containing a cathode, the cathode being coupled to the power supply.   
     
     
         10 . The system of  claim 9  further comprising an ion-exchange membrane adjacent to the anode chamber and the cathode chamber; 
     
     
         11 . The system of  claim 9  where the electrolysis cell is a microbial electrolysis cell. 
     
     
         12 . The system of  claim 9  where the electrolysis cell is a biological electrolysis cell. 
     
     
         13 . The system of  claim 9  where the distribution mechanism comprises a gas-diffusion membrane. 
     
     
         14 . The system of  claim 9  where the distribution mechanism comprises a pump. 
     
     
         15 . The system of  claim 14  where the distribution mechanism is a manifold coupled to the pump. 
     
     
         16 . The system of  claim 9  where the anode comprises carbon fibers. 
     
     
         17 . The system of  claim 9  where the cathode comprises a graphite rod. 
     
     
         18 . A system for dehalogenating organohalides, comprising:
 a contamination site, where the contamination site is contaminated with organohalides, the contamination site comprising:   a first subsurface zone, where the first subsurface zone is saturated with groundwater;   and a second subsurface zone, where the second subsurface zone is not saturated with groundwater;   anaerobic dehalogenating bacteria;   a power supply;   a cathode, the cathode being coupled to the power supply, where the cathode is configured for placement in the first subsurface zone; and   an anode chamber configured to receive organic-containing wastewater, the anode chamber comprising:   an anode, the anode being coupled to the power supply; and   anode-respiring bacteria coupled to the anode.   
     
     
         19 . The system of  claim 18 , where the anode chamber is configured for placement in the first subsurface zone. 
     
     
         20 . The system of  claim 18 , where the anode chamber is configured for placement in the second subsurface zone. 
     
     
         21 . The system of  claim 18 , where the first subsurface zone is a dense non-aqueous phase liquid zone. 
     
     
         22 . The system of  claim 18  where the anode comprises carbon fibers. 
     
     
         23 . The system of  claim 18  where the cathode comprises a graphite rod. 
     
     
         24 . A system for dehalogenating organohalides, comprising:
 a pump configured to pump water, the water being contaminated with organohalides; a power supply;   a cathode chamber, comprising:   anaerobic dehalogenating bacteria; and   a cathode coupled to the power supply;   where the cathode chamber is configured to receive water, the water being contaminated with organohalides, and where the cathode chamber is configured to generate hydrogen gas; and   an anode chamber configured to receive organic-containing wastewater, comprising: an anode coupled to the power supply; and   anode-respiring bacteria coupled to the anode.   
     
     
         25 . The system of  claim 24  where the anode comprises carbon fibers. 
     
     
         26 . The system of  claim 24  where the cathode comprises a graphite rod.