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t7 a i DECHLORIMATI013 OF TETRACKLOROETHERE (PCE) In the July, 1193 issue of Environment Today, a news magazine of environmental management and pollution control, an article discusses the breakdown of Tetrachlaroethene (PCE). The following excerpt from that article, which is an interview with DuPont Senior Environmental Specialist Jack Buttram, details the process. Please note that the terms aerobic (requiring oxygen) and anaerobic (not requiring oxygen) are used. Bio-gem's H-10 Product contains microorganisms that are microaerophilic which means they utilize the available oxygen contained in subsurface soil and groundwater. They do not require additional oxygen to facilitate the operation of the process. Initial attempts to dechlorinate PCE and trace benzene using aerobic treatment were largely unsuccessful, says DuPont senior consultant David Ellis. Anaerobic dechlorination, they discovered, is amazingly orderly. First the DIcrobes strip a single chlorine off all the PCIS producing TCS. Then they will consume the next round of chlorine atoms from the TCE, forming DCE. The process continues down the chain to chloroethane (CA) and vinyl chloride M). The site ties operated under sulfate-reducing conditions to control the amount of vinyl chloride produced since methanogenic conditions might lead to the generation of large amounts of the cancer-causing compound. The final products are ethane and ethene, both considered non-toxic, according to Buttram. "that 's unique about this process 1s that the reactions are taking place 7® feet belou the surface, " says Buttram. "In our larger systems ve'll Inject the nutrients below the surface and use the existing pump- and-treat withdrawal sells to move the !nutrient laden} hater across a 10 acre contaminant plume. " After a fen months of anaerobic treatment at the site, PCE, TCE and DCE concentrations vere reduced to less than 5 ppb. Groundwater PCS and TCE concentrations here reduced by 98X in two monitoring dells uithln a month. The above article explains the importance of an anaerobic environment. Bio- Rem's H-10 Product contains microaerophilic microorganisms which operate similar to those described in the DuPont project. The enzymes in Bio-Item's H-10 Product grab the carbon and releases the hydrogen and chlorine. Hydrogen and chlorine do not readily coobine. The chlorine instead will bond with iron, potassium and calcium, forming chlorides. In the DuPont project, nutrient-laden water was pumped into the contaminant plume. When nutrient is added to the soil, undesirable elements might also grow as they utilize the nutrients meant to bolster the friendly bacteria. With Bio- f Rem's H-10 the nutrient is used up during the initialization and propagation