Phytoremediation of Hazardous Wastes
Technical rept. 23-26 Jul 95
ENVIRONMENTAL PROTECTION AGENCY ATHENS GA ENVIRONMENTAL RESEARCH LAB
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A new and innovative approach to phytoremediation the use of plants to degrade hazardous contaminants was developed. The new approach to phytoremediation involves rigorous pathway analyses, mass balance determinations, and identification of specific enzymes that break down trinitrotoluene TNT, other explosives RDX and HMX, nitrobenzene, and chlorinated solvents e.g., TCE and PCE EPA 1994. As a good example, TNT is completely and rapidly degraded by nitroreductase and laccase enzymes. The aromatic ring is broken and the carbon in the ring fragments is incorporated into new plant fiber, as part of the natural lignification process. Half lives for TNT degradation approach 1 hr or less under ideal laboratory conditions. Continuous-flow pilot studies indicate that scale up residence times in created wetlands may be two to three times longer than in laboratory batch studies. The use of created wetlands and land farming techniques guided by rigorous field biochemistry and ecology promises to be a vital part of a newly evolving field, ecological engineering.
- Solid Wastes and Pollution and Control
- Water Pollution and Control