Chementator: Decontaminate soil using electrons to make microbe’s meals  

The Lawrence Berkeley National Laboratory (LBL; Berkeley, Calif.; www.lbl.gov) has developed a new xenobiotics bioremediation system that can be used to treat contaminated soil and water. Whereas conventional bioelectrical remediation methods rely on the addition of chemicals to provide electron donors or acceptors to stimulate the remediative organism’s metabolic process, LBL’s system uses an electrical current to electrolyze the contaminated liquid in a single-chamber bioreactor, producing hydrogen at the cathode and oxygen at the anode (diagram). These gases are then bioavailable to stimulate the activity of microorganisms to biodegrade or biotransform an extensive range of xenobiotics into benign end-products. By eliminating the use of organic electron donors, operating costs are reduced, says LBL. Since there is a separation of the carbon source and the energy source used by the microorganisms, the rate of contaminant removal is separated from the rate of growth of the organisms. This significantly decreases the amount of biomass produced, which is commonly the cause of biofouling and downstream water-quality issues. The process also allows users to control electron donor or acceptor production by adjusting the electrical…