A stepped sunken green space for purifying surface rainwater runoff

Abstract

The invention discloses a step type low elevation greenbelt for purifying surface rainfall runoff. The step type low elevation greenbelt comprises a road shoulder, a high position region and a low position region from inside to outside, wherein the elevation of the road shoulder, the elevation of the high position and the elevation of the low position region are sequentially and gradually decreased. The road shoulder, the high position region and the low position region are connected through a herbal plant belt. The high position region sequentially comprises a planting soil layer I, a coarse sand layer and a gravel layer I, herbal plants are planted on the planting soil layer I, a pipeline is laid in the gravel layer I, and the other end of the pipeline is led to the low position region. The low position region sequentially comprises a planting soil layer II, a fine sand layer, an oxygen slow-release material layer, a gravel layer II and a geosynthetic clay liner, and an overflow opening is formed in the low position region. Herbal plants are planted on the planting soil layer II, and a perforated drainage pipe is laid in the gravel layer II. Water is converged to the overflow opening through the drainage pipe, and the overflow opening is communicated with a rainwater pipe duct. According to the low elevation greenbelt, SS entering the low elevation greenbelt is remarkably reduced, the content of dissolved oxygen in a low elevation greenbelt matrix is increased through an oxygen slow-release material, and the degradation capacity of COD and nitrogen and phosphorus pollutants is enhanced.

Description

technical field [0001] The invention relates to a stepped sunken green space for purifying surface rainwater runoff, which belongs to the field of environmental engineering. Background technique [0002] At present, with the acceleration of urbanization, the number of impermeable surfaces such as roads, bridges, and buildings in cities continues to increase, the infiltration of rainfall runoff gradually decreases, and the surface runoff increases sharply. A large amount of pollutants in the rainstorm washes away with the runoff through urban drainage pipes or overflows into rivers, lakes and other receiving water bodies, forming typical urban rainfall runoff pollution, because it carries a large amount of SS, COD and nitrogen and phosphorus pollutants. The impact on the environment has seriously restricted the improvement of urban water environment quality. [0003] The sunken green space is a public green space whose elevation is lower than the surrounding road surface. It...

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Problems solved by technology

[0004] Purpose of the invention: the technical problem to be solved by the present invention is to provide a stepped concave green space for purifying surface rainwater runoff. The concave green space of the present invention not only effectively reduces the accumulation of SS on the surface of the green space, but also prolongs the use of the green space It also solves the problem of low dissolved oxygen rate in the concave green matrix. Through the slow-release oxygen effect of the slow-release material, the green space’s ability to remove pollutants such as COD and nitrogen and phosphorus in the initial rainwater is enhanced, thereby effectively curbing The pollution of the receiving water body by the initial rainwater

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