Enhanced denitriding and dephosphorizing bioretention pond applied to construction of sponge city

Abstract

The invention relates to an enhanced denitriding and dephosphorizing bioretention pond applied to construction of a sponge city. The enhanced denitriding and dephosphorizing bioretention pond is characterized in that existing low-lying plots in a city are utilized to construct the bioretention pond; overland runoffs generated nearby are gathered in the bioretention pond for accumulating and are subjected to purification treatment by pipelines, artificial water catchment channels or natural terrains; treated rainwater is used for recycled water of urban afforestation or supplemented groundwater or is directly discharged to a near water area; the bioretention pond comprises three parts: a prepositive primary settling area, a filtering area and a purified water reaction area, wherein the three parts are sequentially communicated. The enhanced denitriding and dephosphorizing bioretention pond has the advantages that multiple technologies of seepage, retention, storage, purification, use and discharge are integrated; the key point is that an enhancing effect is realized in a water purifying function, and the quality of effluent is stable; the whole project is simple in structure, convenient to construct and low in construction cost.

Description

technical field [0001] The invention is an enhanced denitrification and phosphorus removal biological retention pond applied to the construction of sponge cities, which can be directly applied to the construction of sponge cities or urban non-point source pollution control projects. It belongs to the field of environmental protection sewage treatment. Background technique [0002] With the rapid development of urbanization in our country, the pressure of urban drainage is increasing day by day. The hardening of urban land has led to a significant increase in urban surface runoff, accelerated water collection, and shortened flood peak generation time, especially during heavy rain or heavy rain. Active areas cause waterlogging. In addition to causing waterlogging disasters, urban rainwater also produces non-point source pollution by scouring sediments on the urban surface and leaching pollutants in the atmosphere. Judging from the previous research results of urban non-poin...

AI Technical Summary

Problems solved by technology

Bioretention tanks can effectively remove a variety of pollutants in stormwater runoff, but the removal effects of N and P vary greatly, especially NO 3 - - The removal rate of N is low, and some retention ponds even have NO 3 - Due to the ammoniation and nitrification in the rain interval, the NO 3 - Accumulates in the soil of the bioretention pond and is released after rainfall, thus causing NO 3 - The removal rate is low

The published invention patent (CN204803077U) proposes to increase the position of the water outlet, create a flooded area, and create an anaerobic denitrification environment, but this method causes the medium in the flooded area to lose its role in water regulation and storage, and has a negative effect on NO3 - The removal effect is not satisfactory

The published invention patent (CN 106006966A) proposes to add high C / N organic matter to the filler layer on the upper layer of the facility, and use wood chips to strengthen the growth of aerobic microorganisms, so that the upper layer facilities will be anaerobic and aerobic during the water inflow period and the dry period. Alternately occurring states allow denitrification to occur in the upper filler layer, but this method is not suitable for urban sponge city construction, ignoring the characteristics of a large number of suspended impurities in urban runoff rainwater, and alternate aerobic anaerobic Oxygen environment should not be controlled, NO 3 - -N removal rate does not necessarily increase

As far as the current situation is concerned, there are still certain limitations in the actual application of existing bioretention ponds in the construction of sponge cities, especially in terms of water purification.

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