| Abstrakt: |
Purpose: Information on the interaction between submerged macrophytes and organic contaminants in sediments is important for successful phytoremediation. In this study, the growth response and remedial function of Potamogeton crispus L. ( P. crispus) to phenanthrene and pyrene in sediments were investigated. Materials and methods: P. crispus was obtained by a tissue culture technique. Surface sediments (top 0-15 cm) were collected from the Haihe River, Tianjin, China. Six different concentrations of phenanthrene and pyrene (8-180 mg kg dry sediment) were spiked in the sediments. At the end of the 54-day experiment, chlorophyll content, plant length and fresh weight, and root morphology were measured. Concentrations of phenanthrene and pyrene in P. crispus and sediments, as well as the activities of polyphenol oxidase in sediments, were analyzed. Results and discussion: P. crispus growth was promoted by polycyclic aromatic hydrocarbons (PAHs) in sediments (range of 8-80 mg kg) and was not inhibited until the PAH concentration was increased to 180 mg kg. Root tip number was the most sensitive parameter. The presence of P. crispus evidently enhanced the removal of phenanthrene and pyrene from sediments by 18.3 − 34.1 and 14.1 − 27.8 %, respectively. The dissipation increments increased with increasing PAH concentration and showed similar values when PAH concentration was >48 mg kg. Plant accumulation of phenanthrene and pyrene counted for less than 1.05 and 2.46 % of the total increments, respectively. Moreover, the presence of P. crispus could improve the activities of polyphenol oxidase. A positive correlation between the dissipation increments of PAHs and the differences of polyphenol oxidase activities between planted and unplanted sediments was obtained. Conclusions: P. crispus could tolerate high doses of PAHs. The growth of P. crispus was stimulated by phenanthrene and pyrene in sediments over a large concentration range. Moreover, the presence of P. crispus enhanced the removal of PAHs, which was closely related to polyphenol oxidase activities as a result of plant growth stimulation. Therefore, P. crispus should be a suitable choice for phytoremediation of PAH-contaminated sediments. [ABSTRACT FROM AUTHOR] |
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