BIOFILTRATION FOR REMOVAL OF PCE AND TCE VAPORS FROM CONTAMINATED AIR

Bench scale biofilters (vapor phase bioreactors) treating a mixture of gases from the headworks of a wastewater treatment plant have removed perchloroethylene and trichloroethylene from the air. In a biofilter using carbon as the support medium, an initial period of adsorptive re moval was followed by biological removal of 61% of the PCE and 48% of the TCE. In a compost biofilter, removals after the initial period wer e 40% for PCE and 49% for TCE. The reactors were dominantly aerobic. B ecause aerobic degradation of PCE has not been observed, it is believe d that degradation occurred by reductive dechlorination in anaerobic z ones within the particles of the support medium.