Stable Carbon Isotope Fractionation of Diethyl Phthalate During Oxic and Anoxic Degradation in Estuarine Sediment

摘要

Diethyl phthalate was degraded by mixed microbial in estuarine sediment under oxic and anoxic conditions in a laboratory-microcosm. The respective degradation rate constants of diethyl phthalate under both conditions were 0.103 and 0.069 day~(-1), with respective half-lives of 6.7 and 10 days. Stable carbon isotopic fractionation produced by biodegradation of diethyl phthalate was evaluated with compound-specific isotope analysis under both conditions. A small ~(13)C-enrichment in residual diethyl phthalate at advanced stages of biodegradation under both conditions was observed, which was 1.8 and 0.7 %, respectively. The isotopic enrichment observed in the residue provided the direct evidence of diethyl phthalate biodegradation in estuarine sediment,