Estimation of Carbon Recovery and Biomass Yield in the Biofiltration of Octane

Abstract

Abstract

Octane was eliminated from contaminated air in a biofilter at concentrations ranging from 500–2,000 ppm, with a maximum elimination capacity of 90 g/m³ h. After periods of shutdown of up to 30 days, the biofilter rapidly reacclimated, recovering its destruction and removal efficiency (overall octane removal) within 1–2 h of restart; this recovery was shown to be due to biodegradation and not simply adsorption of the octane. Carbon recovery during restart was estimated to be approximately 0.25 mol CO₂/mol C, based on on-line carbon dioxide monitoring, corresponding to a nonsteady state biomass yield of 1.19 g biomass/g octane. In separate respirometry experiments, carbon recovery was estimated to be 0.85 mol CO₂/mol C, corresponding to a biomass yield of 0.24 g biomass/g octane. These results, together with literature values for other systems, suggest that for biofilter modeling purposes a steady-state value of biomass yield in the range 0.17–0.43 g biomass/g carbon source would be appropriate, but dynamic models will require more detailed analysis of the biodegradation pathway.