Method and system for treating agricultural non-point source pollutants in hilly area by multilevel wetlands

Abstract

The invention discloses a method and a system for treating agricultural non-point source pollutants in a hilly area by multilevel wetlands. The method comprises the following steps: A, designing and constructing a diversion facility and multilevel wetlands (including a grit chamber and drop water dams); B, configuring plants in ecological wetlands; C, stocking fish in wetlands; and D, managing and maintaining the ecological wetlands: 1) cutting and utilizing the wetland plants; 2) desilting; and 3) harvesting the fish. The diversion facility is connected with the grit chamber through a diversion covered channel/tube, the grit chamber is respectively connected with the diversion covered channel/tube and the first level wetland, the third level wetland is connected with the second level wetland and the fourth level wetland respectively through overflow channels, a wetland total water drainage opening is respectively connected with the fourth level wetland and a water drainage ditch, and all the wetlands are connected with the drop water dams through overflow channels. The method and the system have the advantages of low running cost, simplicity in operation, excellent treatment effect on non-point source pollutants nitrogen and phosphorus in a small basin or catchment area unit, and very good promotion and application prospect in subtropical hilly areas in the middle and lower reaches of the Yangtze River.

Description

technical field [0001] The present invention relates to the field of agricultural environment, more specifically to a method for treating agricultural non-point source pollutants in the downstream of small watersheds distributed with farmland and small farmers, and also relates to a multi-level wetland system for treating agricultural non-point source pollutants in hilly areas , especially suitable for ecological control of agricultural non-point source pollution in subtropical hilly areas south of the Yangtze River, to improve water quality and reduce nitrogen and phosphorus pollutants. Background technique [0002] With the increase in the input of chemical fertilizers in the planting industry and the rapid development of the livestock and poultry breeding industry, the environmental problems caused by the discharge of agricultural non-point source pollutants in the vast rural areas have become increasingly prominent. According to the results of the 2010 National Survey of...

AI Technical Summary

Problems solved by technology

In terms of ecological control of farmland non-point source pollution, at present in China, mainly by planting aquatic plants mainly emergent plants to build ecological ditches or artificial wetlands, the reduction of nitrogen and phosphorus pollutants has achieved certain results, but due to the general environment Governance rarely has economic benefits, and the governance funds are mainly invested by the government. The enthusiasm of the masses is not high, and the sustainability is poor. Therefore, the scope of technology promotion is limited to a certain extent.

Although the local governments of several large lakes and their surrounding areas in China have spent a lot of manpower and material resources to control eutrophication through engineering control measures, the overall effect achieved is not satisfactory compared with the invested funds. The reasons are mainly manifested in three aspects: 1) Existing measures still focus on terminal treatment of polluted water bodies, but the source of pollutants has not been effectively controlled; 2) The treatment model based on engineering measures has led to excessive treatment costs. 3) Although ecological management has become the development trend of non-point source pollution control, most technologies have low efficiency and lack of sustainable operation mechanism And other issues

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