Our country is a country with serious water shortages. The lack of fresh water resources has seriously affected the social and economic development of many areas of our country. At the same time, the water pollution situation has become increasingly serious in recent years. Eutrophication problems in some rivers and lakes under national key monitoring are prominent, cyanobacteria and blooms occur frequently, and water shortages have caused frosting on the originally scarce freshwater resources. Non-point source pollution is the main cause of the deterioration of water quality in rivers and lakes. Compared with point source pollution, non-point source pollution has the characteristics of multiple points, wide areas, and dispersion. It is difficult to control, and it is difficult for treated effluent to meet emission standards. Typical representative non-point source pollution control technologies at home and abroad include soil purification tanks in Japan, land filtration systems in Europe, and artificial wetlands in the United States and Europe.
However, the above technologies have certain limitations in using non-point source pollution control. The specific manifestations are that first, a large area of land needs to be used. Second, the nitrogen and phosphorus concentration in the treated effluent is still very high, and a large amount of tail water discharged into the water will still cause greater pollution. Therefore, the technical bottleneck of non-point source pollution control is how to achieve efficient nitrogen and phosphorus removal in wastewater with less land and low cost. With funding from the National Water Special Project, the National Natural Science Fund, and international cooperation projects, after years of continuous research, the project team has innovatively invented key technologies for non-point source pollution control that can efficiently remove nitrogen and phosphorus, mainly including the following three breakthroughs. Sexual core technology invention.
1. Invented a composite tower ecological filter suitable for rural domestic sewage and livestock breeding wastewater treatment, which not only realized the small area occupied by the device in sewage treatment, extremely low investment cost and operation cost, but also solved the technical problem of low nitrogen and phosphorus removal rate commonly existing in sewage treatment at home and abroad. The removal rate of nitrogen, phosphorus and organic matter can reach more than 95%. The effluent quality can not only meet the Class A standard of the Discharge Standard of Pollutants for Urban Sewage Treatment Plants (GB18918 -2002), but also can meet the Class IV water standard of surface water. The effluent can be used for irrigation or landscape water.
2. Invented a new artificial wetland suitable for the control of farmland non-point source pollution and low-polluted surface water, achieving efficient treatment of organic matter, nitrogen and phosphorus and other pollutants, and efficient removal of sewage NH3-N and TP mainly from surface runoff; Combined with ecological slope protection, ecological buffer zones and plant ponds and other ecological elements, a landscape park-style design and construction has been formed according to local conditions, and reasonably set up, which not only completes the effective removal of pollutants but also beautifies the environment, and the effluent water quality reaches the first-level A standard.
3. Technologies such as ecological floating beds, ecological "jellyfish" and ecological waterfalls have been invented based on water plant restoration, and an enhanced water plant space construction technology integrating aquatic plants, fillers, microorganisms, aquatic animals and other active elements has been formed. It can inhibit cyanobacteria, improve water quality, and promote the recovery of water ecosystems through competition for niche.
The above-mentioned invention technology has been widely promoted and applied in the three lakes (Taihu Lake, Chaohu Lake, and Dianchi Lake) basins of my country, such as Jiangsu, Zhejiang, Shanghai, Yunnan-Guizhou Plateau, Anhui, Henan and other places, and more than 100 demonstration engineering devices of various types have been established, benefiting hundreds of thousands of rural people, with significant social benefits and wide praise.
This project has obtained 9 authorized national patents and 3 authorized invention patents for core technologies. The Achievement Appraisal Committee of the Ministry of Education believes: "The project is highly innovative, the technical performance developed has reached the international advanced level, and the efficient ecological denitrification technology is superior to the international similar level. It agrees to pass the appraisal and recommends accelerating the promotion and application of this series of technologies."