Design and Application of Plant Ecological Space Technology in Water Eutrophication Control

Abstract

The use of aquatic plants has recently become a popular technique for ecological restoration and purification of eutrophic rivers and lakes. In this paper, various technologies were studied and designed against the background of research and demonstration projects for pollution control in Dianchi Lake and comprehensive improvement of water quality. Different technical units were designed in the horizontal and vertical spaces of the water body. Horizontal spaces included plant buffers on the surface, algae enrichment and diversion, innovative floating beds, and emerging plant zones at the shoreline. Vertical spaces include ecological floating beds, ecological jellyfish, and ecological membrane coverings. Spatial growth patterns of aquatic plants were constructed with rational use of water space and integration with various techniques to maximize the absorption of nutrients in the lake, increase the transparency of the water, and alleviate lake eutrophication. The previous technologies were combined, and technical demonstrations were conducted using experiments. We set up an integrated technical demonstration district with an area of 0.25 km2 on the north shore of Dianchi Lake, and the results demonstrated the following: water transparency increased by >50 cm; algae biomass decreased by >70%; and the percent removal of total phosphorous (TP), total nitrogen (TN), and chemical oxygen demand (CODMn) was >30%.