Phytoremediation of sediments polluted with phenanthrene and pyrene by four submerged aquatic plants

作者：He, Yang; Chi, Jie^*

来源：Journal of Soils and Sediments, 2016, 16(1): 309-317.

DOI：10.1007/s11368-015-1221-4

• Phytoremediation
• Plant species
• Polycyclic aromatic hydrocarbon
• Root oxygenation
• Submerged aquatic plants

Plant species was considered to be a significant factor influencing the efficiency of phytoremediation. Therefore, the ability of four submerged aquatic plants to facilitate the remediation of sediments polluted with polycyclic aromatic hydrocarbons (PAHs) was compared. @@@ Surface sediments (top 0-15 cm) were collected from the Haihe River, Tianjin, China, and spiked with a mixture of phenanthrene and pyrene (about 15 mg kg(-1) dry sediment of each PAH). Four submerged aquatic plant species (Hydrilla verticillata, Myriophyllum verticillatum, Vallisneria spiralis, and Potamogeton crispus L.) were used for the remediation experiment. The experiment lasted for 54 days. Plant length and fresh weight, and root morphology were measured. Concentrations of phenanthrene and pyrene in plants and sediments were analyzed. Sediment redox potential and PAH-degrading bacterial population were also determined. @@@ During a 54-day experiment, more PAHs were dissipated in planted sediments than in unplanted sediments. At the end, dissipation ratios of phenanthrene and pyrene were 48.0-85.3 and 45.7-82.4 % in planted sediments but only 33.9 and 38.3 % in unplanted sediments. Dissipation ratios of the PAHs were significantly different among the four plant species and were the highest in sediments with V. spiralis. Mass balance calculation showed that plant accumulation of phenanthrene and pyrene accounted for less than 1.0 and 6.9 % of the dissipation increments, respectively. Among the plants tested, there were significantly positive correlations between PAH dissipation ratios and sediment redox potentials. @@@ The results suggested that different from terrestrial plant, enhanced dissipation of PAHs by submerged aquatic plants might be mainly attributed to differences in root oxygenation capabilities. Furthermore, root oxygenation may be a useful tool in screening plants for efficient remediation of PAH-polluted sediments. Extension of these results to field-aged PAH-contaminated sediments needs further investigation.

• 出版日期2016-1
• 单位天津大学