Purification of Eutrophic Water by Five Aqua-Cultured Plants in Lake Hongfeng, Guiyang, China

Abstract

The purification efficiency of eutrophic water by five aqua-cultured plants (Chlorophytum comosum, Salix babylonica, Dracaena sanderiana, Myriophyllum verticillatum, Alternanthera philoxeroides) in Lake Hongfeng, China, was investigated. The results indicated that the biomass of Myriophyllum verticillatum and Alternanthera philoxeroides reached the highest level in 87 days after transplant. The removal efficiencies of total nitrate (TN), total phosphorus (TP), chemical oxygen demand (CODCr), and chlorophyll (Chl-a) by the plants ranged from 44% to 96%. The Secchi depth (SD) increased from 0.08-0.1 m to 1.3-3.2 m for the experiments with five cultivars of aqua-cultured plants. Purification efficiency of eutrophic water correlated significantly, in a positive way, with biomass amount and plant productivity. The Carlson’s trophic state indexes decreased from 76 to 21 when the cultivar was Myriophyllum verticillatum, suggesting that Myriophyllum verticillatum can be selected as the plant to remediate karst drainage areas of Guizhou Plateau, where the water body underwent eutrophication. The research results provided a good case for lake environmental management and recovery in karst areas of Yunnan-Guizhou Plateau, China.