This project belongs to water pollution remediation technology, which comprehensively applies multi-disciplinary theories and methods such as environmental ecology, plant physiological ecology, microbiology, molecular biology, and nanotechnology.

The project focuses on freshwater waters polluted by harmful algae caused by eutrophication:

1)Two plants with strong pollution resistance and pollution absorption, strong environmental adaptability, suitable for outdoor growth, and high economic value were selected from common ornamental plants. Base of ecological restoration system for eutrophic freshwater water bodies;

2)Dominant indigenous strains H1, D1, T5, and K2, which have good removal effect on harmful algae, were isolated from the immobilized aquatic microbial system symbiotic with the plant's roots, and the best composite bacterial agent formula was formulated through bacterial selection experiments: H1 bacteria and T5 bacteria were mixed in a ratio of 1:1, and a certain amount of K2 bacteria was added according to the actual environment of the applied water body to enhance the buffering capacity of the composite bacterial community to changes in the water environment;

3)Further, in order to deal with the microcystin released after the rupture and death of algae cells (A human and livestock liver toxin and liver tumor promoter. It is a secondary metabolite of Microcystis aeruginosa. Most of it exists in the cell. The algae cells rupture and are released into the water body, endangering public safety.), selected from sludge. Highly efficient algae toxin-degrading bacteria W2 and W4 are mixed and mixed in a ratio of 2:1. This bacteria group can convert microcystis into non-toxic substances through metabolism and inhibit algae growth and algal toxin production; It is combined with nano semiconductor visible light catalytic oxidation particles to form a composite coating to achieve in-situ purification of microcystin under outdoor visible light conditions. This in-situ purification technology discovered and applied for the first time a new mechanism for oxidizing microcystins by NO free radicals. As a result, an efficient, adaptable and ornamental plant-microbial complex artificial ecosystem was constructed to restore eutrophic freshwater waters polluted by harmful algae.

The plant-microbial composite ecological restoration system developed by the project has high efficiency, strong environmental impact resistance, and good adaptability. It can adapt to a variety of different environmental conditions of subtropical and temperate small and medium-sized freshwater bodies; it has no residue, no toxicity, and no secondary pollution. It can work efficiently under natural light conditions in the wild without secondary construction and maintenance; The core plants of the system are colombia and bergamot vine green velvet, two crops with strong ornamental and economic value, which are especially suitable for application in urban and rural rivers.

The results of this project have played a good role in many freshwater river and lake management and restoration projects in China, such as the ecological river restoration project in Zhoushi Town, Kunshan City, Jiangsu Province, the water bloom control in the Xichan Temple Fangsheng Pond in Fuzhou City, Fujian Province, and the 36th foot lake comprehensive management project in Pingtan County, river management in Shanghai World Expo Park, river restoration in Shanghai Qingpu Township, river restoration in Shanghai City Gongqing Forest Park, water environment protection and restoration in Jinan Suburban River Basin, and water environment protection and restoration in Anhui Taiping Lake Basin. Comprehensive Rural Environment Improvement Project in Linfen City, Shanxi Province, River Regulation Project in the Economic Development Zones of Wuxi City and Xuzhou City, Jiangsu Province, etc. The results show that after restoration, all water quality indicators of the river, such as N and P content, have reached the corresponding national standards, and the project investment has saved 30%-65%, achieved ideal social and ecological benefits, and increased the landscape value of the river.