Characterization of Alpha-Pinene-Degrading Microorganisms and Application to a Bench-Scale Biofiltration System for VOC Degradation

Abstract.

A study was conducted to isolate and characterize monoterpene-degrading microorganisms and apply them to a biofiltration unit for use in degrading high levels of α-pinene. Soil from a monoterpene-contaminated site was used with enrichment culture techniques to recover a consortium of bacteria able to utilize α-pinene as the sole source of carbon and energy. The Biolog system was utilized to identify the bacteria as Pseudomonas fluorescens and Alcaligenes xylosoxidans. Aerobic growth and biodegradation studies confirmed that rapid growth and biodegradation were being achieved with α-pinene. Complete degradation of α-pinene was achieved in 36 h with a maximum rate of degradation of 3.9 mg/L/h. The microorganisms were placed in a biofiltration column and demonstrated good removal of α-pinene from an air stream at concentrations averaging 295 ppmv. A nitrogen test was performed and confirmed that the removal of α-pinene was due to biological activity. Given the ability of these microorganisms to utilize high levels of α-pinene, they will be used in a coupled treatment system using a physical/chemical adsorption/desorption unit coupled to a biofiltration column. Often, biofiltration studies are performed using much lower levels of analyte in the influent air stream. However, the ability of these microorganisms to utilize higher levels of compounds expands the capabilities for future coupled biofiltration systems. During future studies, high flow rates with low levels of analyte will be concentrated so that a higher analyte concentration and lower flow rate can be utilized with the biofilter.