| Summary: | 碩士 === 國立中央大學 === 環境工程研究所 === 91 === The hydrophobicity of polycyclic aromatic hydrocarbon compounds (PAHs) results in these compounds being strongly sorbed to soils. The use of surfactants may change the sorption behavior of PAHs in soil environment. Biodegradation is believed an important pathway for removal of PAHs contamination from soil-water systems. The aim of this study was to evaluate the degradation capability of fungal laccase in degrading PAHs including naphthalene and phenanthrene contained in soil-water systems with nonionic surfactants. The nonionic surfactants selected were Triton X-100 and Brij 35. A comparative study was carried out by application of free and immobilized laccases in the soil-water system.
In aqueous, addition of Triton X-100 and Brij 35 resulted in enhancement the biodegradation of PAHs. When micelles existed in water systems, PAHs biodegradation was greater than that of below critical micelle concentration (CMC). The same results were also found in soil-water systems. The phenomena can be ascribed to more PAHs partition on into micelles than that of monomers. This situation leading to bioavailable on micellar phase is more effective. To compare the biodegradation rate in difference phase, the results show that in aqueous phase was higher than that of soil phase. On immobilized laccase systems, an inhibition biodegradation in the presence of Brij 35 was observed, and an opposite effect presented in the presence of Triton X-100. Differences phenomenon in bioavailability may correlate with steric hindrance of immobilized laccase and longer polyoxyethylene chain of Brij 35.
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