Ecological filter zone system for retarding farmland non-point source pollution and construction method thereof

Abstract

The invention discloses an ecological filter zone system for preventing farmland non-point source pollutants from entering a river. The system comprises at least one filter strip unit arranged in a gradient manner. A fine sand layer is laid between the bottom of the filtering band unit and the soil. A gravel band is laid at the water inlet end of the filtering band, which is close to the farmlandside. A gravel band is laid at the water outlet end of the filtering band, which is close to the river channel side. The filtering band unit comprises a containing groove with the periphery and the bottom closed, and a filler layer, a water-permeable geotextile layer and a covering layer, which are sequentially arranged from bottom to top. A water-permeable hole is formed in the bottom of the accommodating groove. The filler layer comprises a zeolite layer, a ceramsite layer and an anthracite layer. The functions of blocking pollutants and purifying water are synergistically completed by utilizing the filtration and adsorption effects of the filler on farmland runoff pollutants, the degradation effect of soil microorganisms on organic pollutants and the absorption effect of plants on nitrogen and phosphorus. On one hand, the system can prevent farmland non-point source pollutants from entering a river channel, and on the other hand, a natural river bank can be beautified to form a certain landscape effect.

Description

technical field [0001] The invention belongs to the field of ecological restoration of riverbank water bodies, and in particular relates to an ecological filter belt system and a construction method for blocking farmland non-point source pollution. Background technique [0002] In recent years, due to climate change, the impact of human activities and social and economic development, my country's water pollution situation has become more and more severe. The water quality of many important water systems has been deteriorating, and the problem of eutrophication has become prominent. Soil erosion in some water source areas has caused surface soil damage and river sedimentation. At the same time, due to the impact of fertilization and rainfall, some farmland pollutants have entered river water bodies with rainfall or irrigation runoff. This kind of farmland non-point source pollution has seriously affected water sources. land water safety and water environment quality. [0003...

AI Technical Summary

Problems solved by technology

Soil erosion in some water source areas has caused surface soil damage and river sedimentation. At the same time, due to the impact of fertilization and rainfall, some farmland pollutants have entered river water bodies with rainfall or irrigation runoff. This kind of farmland non-point source pollution has seriously affected water sources. Land water safety and water environment quality

[0003] In this context, blocking pollutants from entering the river has become an important means of controlling non-point source pollution. From a technical perspective, there are many measures that can achieve the desired results at this stage, such as vegetation buffer zones and riverside tree-shrub-grass multi-level buffers belt, multi-stage filter bed ecological bank slope, etc., but the above-mentioned technologies have high requirements on topographical conditions, and are generally applicable to areas with wide river bank belts and sufficient construction space, but cannot be applied to some river areas near water sources near farmland , so it is of theoretical and practical significance to construct a river bank ecological filter belt that can efficiently block farmland non-point source pollution under limited terrain conditions

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