Using Solid-Phase Microextraction to Estimate Benzene Bioavailability for Use in Predicting Bioremediation Efficacy

摘要

Bioremediation is a microbiological process where microorganisms decompose contaminants readily available in soil solutions. Many soil extraction techniques have been used to assess the bioavailable fraction of a contaminant. In this study, solid phase microextraction (SPME) method has been developed and verified to estimate the availability of benzene for microbial decomposition. Three different types of genuine soils were artificially contaminated with benzene at 25 μ/kg soil. Batch biodegradation tests were performed for a 6-week period at 10°C and room temperature, respectively. Extractions of benzene in soil solutions by SPME were carried out, after reaching equilibrium state, at 40 h after the artificial contamination. During the biodegradation tests conventional extraction techniques were employed to determine the benzene concentrations in aqueous as well as in solid phases. Relationships between residual benzene concentrations following SPME (RC_(ext)) and residual benzene concentrations following biodegradation (RC_(bio)) were then established. It was found that the correlation coefficient (r~2) of the two RCs was as high as 0.884. These results indicated that the microbially bioavailable concentrations of soil-associated benzene were best predicted by SPME. The rapid extraction method therefore provides an attractive approach for the assessment of bioremediation efficacy.