Subsurface flow constructed wetland system of secondary effluent from sewage treatment plant and application thereof

Abstract

The invention discloses a subsurface flow constructed wetland system of secondary effluent from a sewage treatment plant and an application thereof, and the subsurface flow constructed wetland system comprises a subsurface flow constructed wetland device, water passing tracery walls are respectively arranged on the water inlet side and the outer outlet side of the subsurface flow constructed wetland device, the water passing tracery walls are provided with water seepage holes, a wetland matrix and wetland plants are arranged between the water passing tracery walls on the two sides, and a bottom artificial aeration device is arranged at the bottom part of the subsurface flow constructed wetland device; a pre-aeration device is arranged outside the water passing tracery wall on the water inlet side, and a water collection device is arranged outside the water passing tracery wall on the water outlet side; and a high-level water tank is arranged on the water inlet side, the horizontal position of the high-level water tank is higher than the pre-aeration device and the subsurface flow constructed wetland device, and the high-level water tank is communicated with the pre-aeration device through a water inlet pipe. The subsurface flow constructed wetland system has the advantages of simple structure, low energy consumption, low cost, high nitrogen and phosphorus removal efficiency, small occupied area, convenient operation management, convenient sampling and the like. The subsurface flow constructed wetland system is particularly applicable to treatment of the secondary effluent of the urban sewage treatment plants and applicable to the treatment of other micro-polluted water.

Description

technical field [0001] The invention relates to a water treatment technology, in particular to an underflow artificial wetland system for secondary outlet water of a sewage treatment plant and its application. Background technique [0002] Although the secondary treatment of urban sewage treatment plants has reduced various pollutants in the sewage to a large extent, the relative concentration of N, P and other pollutants in the effluent is still high, and the C / N is low. When these pollutants enter the receiving water body along with the effluent from the sewage plant, it is easy to cause eutrophication of the receiving water body. [0003] In the prior art, the advanced treatment processes of urban sewage treatment plants mainly include membrane bioreactor (MBR) process, biological aerated filter (BAF) process and CASS process, etc., which are backward in process, large in infrastructure investment, and difficult to operate. High cost, unsatisfactory water quality after t...

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Problems solved by technology

[0002] Although the secondary treatment of urban sewage treatment plants has reduced various pollutants in the sewage to a large extent, the relative concentration of N, P and other pollutants in the effluent is still high, and the C / N is low

When these pollutants enter the receiving water body along with the effluent from the sewage plant, it is easy to cause eutrophication of the receiving water body

[0003] In the prior art, the advanced treatment processes of urban sewage treatment plants mainly include membrane bioreactor (MBR) process, biological aerated filter (BAF) process and CASS process, etc., which are backward in process, large in infrastructure investment, and difficult to operate. Disadvantages such as high cost and unsatisfactory water quality after treatment

Membrane bioreactor (MBR) process, the system requires a lot of oxygen, high energy consumption, the accumulation of refractory biodegradable substances is likely to cause microbial poisoning and membrane pollution, and the price of membrane modules is currently relatively expensive; biological aerated filter (BAF ) process, the system startup speed is slow, the biofilm is likely to fall off during the backwashing process, and the operation management is more complicated; the CASS process, although the process is simple, but the efficiency of biological nitrogen and phosphorus removal is difficult to improve, and the control method is relatively simple

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