A bioretention tank filter layer filler and processing method

Abstract

The invention discloses a bioretention pond filter layer filler and a processing method. The bioretention pond filter layer filler is prepared from the following raw materials in percentages by weight: 1-2% of a natural organic matter, 45-60% of continuously graded coarse sand, 10-25% of continuously graded medium sand and 25-35% of continuously graded fine sand. By adopting the continuously graded sand, the bioretention pond filter layer filler is more stable than an existing proportion structure layer, the component of original soil is omitted under the premise of ensuring plant growth, and the problem of blockage caused by soil hardening in the operating process of the bioretention pond is solved. Meanwhile, the invention further discloses a factory processing method with the mixture ratio. The raw materials conveyed from a wharf are dried until the moisture content is 1-3% and then stirred evenly, and the initial permeability coefficient also meets the technical requirements. The used raw materials with the ratios are continuously graded, so that the sieving process is omitted, complete drying is not needed in factory production, the procedure is simplified and the cost is reduced.

Description

technical field [0001] The invention relates to the field of sponge city construction, in particular to a filter layer filler of a bioretention pond using localized materials and a processing method thereof. Background technique [0002] The existing bioretention pond technology is mainly a new technology of stormwater management for the continuous development of urbanization, the rapid growth of impervious areas, the pollution of rainwater runoff and the frequent occurrence of urban waterlogging. It is also a new technology for the construction of sponge cities. a key technology. [0003] Commonly used bioretention tank structures such as figure 1 As shown, from top to bottom are retention layer, filter layer, transition layer, water retention layer and drainage layer. The stagnation layer is the regulation and storage volume reserved by the system, which can relieve the flood peak; the filter layer is to remove the pollutants in the rainwater runoff through physical, che...

AI Technical Summary

Problems solved by technology

[0007] In order to ensure the growth of plants, the mixing ratio of the filter layer of the existing bioretention tank is mixed with a certain proportion (10-15%) of the original soil, the proportion is relatively large, but the initial permeability coefficient of the filler reaches 800-1000mm / h, which exceeds the design requirements ;The soil in Kunshan area is sticky soil, the permeability coefficient is small, and the soil will compact after a period of operation, and the permeability coefficient will drop below 100mm / h. The fluctuation range is large, and the hydrological and water quality effects in the later period are poor.

[0008] In the factory production process of the existing bioretention tank filter layer mixing ratio, the raw materials need to be screened, the original soil should be crushed, dried and mixed, which increases the difficulty and cost of production

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