Rhizosphere Effects of Wetland Plants in the Phytoremediation of Coastal Sediments Contaminated with Polycyclic Aromatic Hydrocarbons (PAHs)

Description

The most significant phytoremediation process for organic pollutants such as PAHs is rhizosphere degradation, the breakdown of pollutants by microorganisms in the root zone environment (the rhizosphere). However, the roles of roots and the rhizosphere effects of wetland plants in particular mangroves have never been explored, despite their tolerance to stressed environments. Without a clear understanding of how roots accelerate the removal and degradation of organic pollutants, it is difficult to promote and apply phytoremediation, an emerging technology. The proposed study therefore aims to analyze the process of rhizosphere degradation; evaluate the effects of roots in releasing oxygen to create an aerobic environment in the rhizosphere; and explore the roles of root exudates on degradation, mobility, bioavailability of PAHs, selection of PAH-degraders and changes in the microbial community in sediments. The effectiveness of various mangrove plants on the remediation of coastal sediments contaminated with fresh and aged PAHs will also be examined, and compared with a common wetland plant (Phragmites communis).