phytoremediation of water with different eutrophic characteristics by macrophytes in two life forms

The phytoremediation is considered an effective strategy to improve ecological system, though, the information about the restoration of water with different eutrophic characteristics is still limited. In this study, four treatments (low N and P [LNP, TN 2 mg/L and TP 0.2 mg/L], high N and P [HNP, TN 20 mg/L and TP 2 mg/L], high N only [HN, TN 20 mg/L and TP 0.2 mg/L], and high P only [HP, TN 2 mg/L and TP 2 mg/L]) were set up to investigate the removal of TN, NH 3 -N, TP, and COD by five emergent and four submerged macrophytes, along with their physiological responses and nutrient accumulation. The results showed that the emergent plant Thalia dealbata Fraser (TD) had the highest TN and NH 3 -N removal under HNP (43.01 % and 15.75 %), but under HN it was Canna indica L. (CI), which was also the most efficient at removing TP under HP (22.61 %). Among the submerged plants, Vallisneria natans [Lour.] H. Hara (VN) demonstrated advantages in reducing TN, NH 3 -N, TP, and COD under HNP (61.83 %, 13.69 %, 13 %, and 49.29 %) and Ceratophyllum demersum L. (CD) was the most effective in reducing TP under HP (22.51 %). High N and/or P generally promoted plant growth and increased chlorophyll, but reduced chlorophyll a/b. Overall, under the corresponding treatments, the macrophyte with the best purification also had the highest TN and/or TP concentration. The findings indicated that eutrophic characteristics were important in the selection of restoration species and provided references for the phytoremediation of aquatic ecosystems. • Remediation of HN (high N), HP (high P), and HNP (high N and P) waters was evaluated. • Five emergent and four submerged plants were used to remove TN, NH 3 -N, TP, and COD. • T. dealbata , L. salicaria , M. spicatum , and V. natans were most efficient in HNP. • For HN, the best one was C. indica , and for HP were C. indica and C. demersum . • N and/or P characteristics affected the growth, Chl., and nutrients in the plants.