Determining a Bioventing Scale-Up Factor

Abstract

Bioventing is an increasingly popular means of removing hazardous petroleum products from sites contaminated by industry and underground gasoline storage tanks. A mesoscale bioventing reactor system was used to determine the rate of bioremediation and compared to previous work completed on smaller scale reactors. Ten 4kg reactors with two different soil types were spiked with synthetic gasoline to an initial concentration of 4000mg/kg soil. Vacuum was then applied at a rate of 1mL/min, with sufficient water levels monitored and maintained to induce bioventing conditions. Gas chromatography was used to determine concentrations of synthetic gasoline in soil every two days for each soil type. Results indicate a smaller scale up factor for sandy soils (Delhi), than for clayey soils (Elora). Furthermore it was observed that slower decay rates exist as reactor size increases, suggesting that conservative estimates are needed when transferring lab results to the field