Abstract
Recently, biological method is expected as an alternative remediation technique for soil contaminated with dioxins. Pseudallescheria boydii (P.boydii), which we isolated from sludge in a leachate treatment facility, is able to degrade dioxins. Regarding to P.boydii's dioxin degradation, the fundamental characteristics involving a relationship between cell growth and dioxin-degradation, and an influence of dioxins on cell growth have not ever been investigated. Modeling based on the characteristics provides an estimation of an amount of treated dioxins per cell weight, nutrient demand for degrading dioxins and time for treatment, which are useful for designing a treatment reactor. There are two purposes in this study. One is to investigate the fundamental characteristics of 2,3,7,8-TCDD(TCDD) degradation by P.boydii. On the basis of the degradation characteristics, another is to investigate applicability of the existing mathematical model to TCDD degradation by P.boydii. As a result, P.boydii has degraded TCDD with glucose by a cometabolic process. P.boydii has not been inhibited by 10ng/mL TCDD during its growing. The existing mathematical model based on the degradation characteristics was able to apply to TCDD degradation by P.boydii. A statistically reasonable agreement was obtained between the experimental and calculated data.
