BIODEGRADATION PHENOMENA DURING SOIL VAPOR EXTRACTION - SENSITIVITY STUDIES FOR SINGLE SUBSTRATE SYSTEMS

Biodegradation phenomena may take place during soil remediation by vap or stripping. Mass transfer limitations are likely to occur due to tra nsport of oxygen and the contaminant between the aqueous and gaseous p hases. Sensitivity studies performed with a one-dimension model show t hat under optimal conditions biodegradation substantially reduces the cleanup time, especially when high removal percentages are desired, le ading to lower treatment cost. A first series of runs without nutrient limitations showed that the system is relatively insensitive to chang es in the major biological parameters when severe mass transfer limita tions occur. Nutrient limitations may seriously impair the advantages derived from biodegradation, especially if they occur during the final stages of the cleanup.