Phthalate ester distributions and its potential-biodegradation microbes in the sediments of Kaohsiung Ocean Dredged Material Disposal Site, Taiwan

The aim of this study was to examine the effect of dumping harbor dredged sediments into the ocean on the phthalate esters distribution in the sediments of Kaohsiung Ocean Dredged Material Disposal Site (KODMDS). Compared with the sediments outside the disposal site (Area R), the particle size distribution of sediment in disposal site has no significant difference, because the pattern of particle size distribution in the dredged sediments is similar to that in the sediments of KODMDS. Results indicated that the mean phthalate ester content in the centres of the four disposal areas (Area I) were significantly (p < 0.05) higher than those in Area R, whereas those in the vertex angles of disposed area (Area II) were no significantly higher than those in Area R. This result implied that the dredged sediments were mainly deposited inside the disposal area, and the surface sediments in KODMDS may be impacted by the disposal of dredged sediments. The percentage of sediment samples for phthalate esters content exceeding Maximum Permissible Concentrations (MPC) and/or Ecotoxicological Serious Risk Concentrations (SRCeco) in Areas I and II was higher than that in Area R, indicated that the disposal of dredged sediments may increase the potentially ecological risks for benthic organisms that lived in the surface sediments of KODMDS. However, the present study has found the bacteria have the ability to degrade PAEs in KODMDS, indicating PAEs in KODMDS could be biodegraded eventually.