Abstract:

A typical black-odor urban river sediment in Shanghai was assessed in the study. Six characteristic herbaceous plants, namely Trifolium repens L., Festuca arundinacea, Lolium perenne L., Elymus dahuricus Turcz., Amaranthus hypochondriacus L., and Medicago sativa L., were used as experimental plants in the phytoremediation of Cd-Zn-Cu contaminated river sediment. The tolerance to heavy metals, enrichment and transport features, and remediation efficiencies of the six plants in the river sediment were explored. The results showed that, except for Trifolium repens L., the plants had good tolerance to heavy metals in the sediment. For Cd and Zn, the accumulation ability of Lolium perenne L. was higher, and the content of Zn in the plant was 707.69 mg/kg. The accumulation ability of Elymus dahuricus Turcz. to Cu was relatively higher. The accumulation of heavy metals in the plants was primarily within the roots, except for the accumulation of Zn in Medicago sativa L. The bioaccumulation factor of Cd and Zn in Festuca arundinacea and Lolium perenne L. was greater than 1. Furthermore, the Cd, Zn and Cu extraction efficiencies of Festuca arundinacea and Lolium perenne L. exceeded 7%, 6% and 2%, respectively, which suggested stronger phytoextraction potentiality of the Cd-Zn-Cu contaminated river sediment.

Key words: Cd, Zn, Cu, river sediment, phytoremediation