Hierarchical biofiltration detention system

Abstract

The invention discloses a hierarchical biofiltration detention system, which comprises a detention pond, wherein the top end of the detention pond is open; the pond bottom of the detention pond is vertically provided with a separation wall; and the separation wall is used for separating the detention pond into two independent areas of a first filtering area and a second filtering area. The first filtering area is provided, in the flow direction of rainwater and in a laying manner, with a first gravel layer used for filtering a particulate matter contained in the rainwater and a first water storage layer used for stagnating the rainwater to form an anoxic / anaerobic environment; and the first filtering area is also provided, in a burying manner, with a water inlet pipeline used for guiding the rainwater needing to be treated into the first gravel layer. The second filtering area is provided, in the flow direction of the rainwater and in the laying manner, with a second water storage layer, which is used for storing the rainwater overflowing from the first water storage layer, a covering layer, a biofiltration medium layer, which is used for filtering the residual particulate matter in the rainwater once again and meanwhile adsorbing and degrading a residual organic pollutant in the rainwater, and a second gravel layer, which is used for realizing quick water discharge, in sequence; and the second gravel layer is provided with a water discharging pipeline in the burying manner.

Description

technical field [0001] The invention relates to the fields of sponge city construction and low-impact development, and in particular, relates to a hierarchical biological filtration retention system. Background technique [0002] At present, the traditional urban rainwater "quick drainage" model is no longer suitable for the coordinated development of the economy, society and environment, and a new "sponge city construction" model has emerged as the times require. "Sponge city construction" gives priority to the use of natural drainage systems, builds ecological drainage facilities, and gives full play to the absorption, infiltration, retention, storage and purification of rainwater by urban green spaces, roads, and water systems, so that the hydrological characteristics of the city after development and construction are close to development. To effectively alleviate urban waterlogging, reduce urban runoff pollution load, protect and improve urban ecological environment. ...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a hierarchical biological filtration retention system to solve the problems of rapid growth of head loss, easy formation of water, loss of microorganisms and nutrients in the medium layer, easy pollution of downstream water bodies, and filtration retention period in existing conventional low-impact development facilities. The technical problems of greatly shortening, rapid decline in biological filtration effect and frequent update of filter material

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