LI Pengwu, SUN Rongguo，CHEN Zhuo

 

(College of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001, China)

 

Abstract: In this study, aquatic plants lucky bamboo (Dracaena sanderiana Sander) and iris (Iris tectorum Maxim.) were used separately and in combination for constructing ecological floating beds on simulated karst water and investigating the removal efficiency of excess nutrients. The removal efficiency of different plant groups was also evaluated. Results show that the respective removal rates of COD, TN, NH4+-N, NO3--N, and TP are 61.63%, 44.38%, 94.01%, 13.35%, and 76.48% by lucky bamboo, 28.33%, 51.18%, 88.11%, 26.29%, and 55.25% by iris, and 33.97%, 49.56%, 89.73%, 22.25%, and 49.81% by their combination, respectively. The highest removal rates of TN and NO3--N are by iris, and the highest removal rates of NH4+-N and TP are by lucky bamboo. In addition, effectiveness of the combination on removing TN, NH4+-N, NO3--N, and TP is between those of lucky bamboo and iris alone. These results suggest that the combination of the plants has synergistic effect on the removal rates of excess nutrients in water during their ecological restoration. Based on the growth rate of plants and the removal efficiency of all nutrients, ecological floating beds by using plant combinations are recommended , though the removal efficiency of single plant group is higher than that of combination group.

 

Key words: Karst, ecological floating bed, eutrophication, ecological restoration

 

EARTH AND ENVIRONMENT Vol.45, No.6, Tot No.320, 2017, Page 654-659