CN215975174U

CN215975174U - Enhanced denitrification constructed wetland system

Info

Publication number: CN215975174U
Application number: CN202121581438.5U
Authority: CN
Inventors: 成水平; 陈心仪; 吴娟; 余少乐; 孔令为; 钟非
Original assignee: China Construction Eighth Engineering Bureau General Contracting Construction Co ltd; Tongji University
Current assignee: China Construction Eighth Engineering Bureau General Contracting Construction Co ltd; Tongji University
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2022-03-08
Anticipated expiration: 2031-07-13

Abstract

The utility model provides a reinforced denitrification constructed wetland system, which comprises a water inlet pipe, a water distribution area, a primary sedimentation area, a main function area, a water collection area and a water outlet pipe which are sequentially arranged along the water flow direction; perforated walls are adopted outside the primary settling zone and the main functional zone; the end part of the front end part of the main functional area is provided with an aeration pipe, and the aeration pipe is connected with an aeration pump through a flowmeter; specific wetland plants are planted on the upper part of the main functional area. The system provided by the utility model improves the utilization rate of oxygen of the artificial wetland through the combination of the aeration position and the plants, realizes clear nitrification-denitrification partition in the wetland and enhances the removal effect of the wetland on ammonia nitrogen and total nitrogen.

Description

Enhanced denitrification constructed wetland system

Technical Field

The utility model belongs to the technical field of environmental protection water treatment equipment, and particularly relates to an enhanced denitrification constructed wetland system.

Background

Constructed Wetland (CW) is a structure designed and Constructed for water treatment by simulating a natural wetland system, and mainly uses a composite ecosystem consisting of plant-microorganism-matrix to remove pollutants. Compared with the traditional water treatment process, the constructed wetland has the advantages of low investment cost, convenient operation and management, high ecological benefit, good pollutant removal effect, wide application range and the like. Therefore, the artificial wetland is gradually applied to the fields of urban industrial wastewater, domestic sewage, mine acid drainage, agricultural runoff and the like, and obtains good treatment effect.

Nitrogen is an important factor causing water eutrophication and is also one of important indexes for controlling water pollution. The artificial wetland mainly removes nitrogen through the nitrification and denitrification process of microorganisms in the aerobic/anaerobic alternate environment in the system. And the insufficient dissolved oxygen and the unclear nitrification and denitrification subareas in the artificial wetland become main factors for limiting the denitrification effect of the system. In practical engineering application, artificial aeration and oxygenation are considered to be the most effective reoxygenation way. According to the difference of aeration positions, four local aeration strengthening measures are generally adopted, namely water inlet pre-aeration and aeration of front, middle and rear sections of the artificial wetland. When the aeration quantity is the same, the oxygen charging aeration in the system has higher oxygen utilization efficiency compared with the water inlet pre-aeration, and the front-section oxygen charging aeration is more beneficial to the formation of nitrification-denitrification subareas. The plant is an important component in the ecological purification process of the artificial wetland, the oxygen secretion of the plant root is a main reoxygenation way of the artificial wetland, and the oxygen secretion capacity of the root is closely related to the plant type. The artificial wetland is used as a complex ecosystem, and the influence of different measures on each component in the wetland can generate interaction. However, in recent years, research is mostly based on improving the denitrification efficiency of the artificial wetland by singly adjusting the aeration position or selecting plants, and the continuous efficient reoxygenation requirement and efficient and stable denitrification requirement in large-scale economic application of the wetland cannot be met.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects, the utility model provides the enhanced denitrification constructed wetland system, which improves the utilization rate of oxygen by the constructed wetland through the combination of the aeration position and the plants, realizes clear nitrification-denitrification subareas in the wetland and enhances the removal effect of the wetland on ammonia nitrogen and total nitrogen.

The utility model provides the following technical scheme: an enhanced denitrification constructed wetland system comprises a water inlet pipe, a water distribution area, a primary sedimentation area, a main function area, a water collection area and a water outlet pipe which are sequentially arranged along the water flow direction; perforated walls are adopted outside the primary settling zone and the main functional zone; the end part of the front end part of the main functional area is provided with an aeration pipe, and the aeration pipe is connected with an aeration pump through a flowmeter; specific wetland plants are planted on the upper part of the main functional area.

Furthermore, small holes with the aperture of 1cm are uniformly distributed on the perforated wall.

Further, the aeration pipe is arranged in the front quarter section of the inner part of the main functional area and is 10cm away from the bottom of the system.

Further, the pipe diameter of the aeration pipe is DN 20 mm.

Furthermore, aeration holes with the aperture of 1mm are uniformly distributed above the aeration pipe.

Further, the aeration pump performs intermittent aeration on the system, and the aeration is stopped for 1 hour every 2 hours.

Further, the flow meter controls the aeration rate of the aeration pipe to be 0.5L/min during aeration.

Further, the wetland plant type planted on the upper part of the main functional area is Siberian iris.

The utility model has the beneficial effects that:

the utility model achieves the purpose of uniform water distribution in the system by arranging the perforated wall on the premise of not consuming energy and saving cost.

The bottom of the front end part in the artificial wetland is aerated, and compared with other aeration positions, the utility model can improve the utilization rate of the wetland to oxygen under the same aeration rate, reduce the aeration rate and save the cost.

Compared with continuous aeration, the intermittent aeration mode can improve the removal rate of ammonia nitrogen, does not influence the removal of total nitrogen, and saves the aeration cost to a certain extent.

The utility model aerates at the front end, is beneficial to forming a clear nitrification-denitrification subarea in the wetland, is consistent with the main path of removing nitrogen in the wetland, simultaneously generates interaction between the influence of the oxygen secretion capacity of the Siberian iris root system on the removal of the nitrogen and artificial aeration, and improves the treatment capacity of the artificial wetland by combining aeration positions and plants, particularly the removal capacity of ammonia nitrogen and total nitrogen.

Drawings

The utility model will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

FIG. 1 is a front view of an enhanced denitrification constructed wetland system provided by the utility model;

fig. 2 is a top view of the enhanced denitrification constructed wetland system provided by the utility model.

In the figure: 1. a water inlet pipe; 2. a water distribution area; 3. a primary settling zone; 4. a main functional area; 5. a water collection area; 6. a water outlet pipe; 7. wetland plants; 8. perforating the wall; 9. an aeration pump; 10. a flow meter; 11. an aeration pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the enhanced denitrification constructed wetland system provided by the utility model is a horizontal subsurface flow constructed wetland, and the reactor comprises a water inlet pipe 1, a water distribution area 2, a primary settling area 3, a main functional area 4, a water collection area 5 and a water outlet pipe 6 which are sequentially arranged from left to right; perforated walls 8 are adopted outside the primary settling zone 3 and the main functional zone 4; the bottom of the front end part of the main functional area is provided with an aeration pipe 11, and the aeration pipe 11 is connected with an aeration pump 9 through a flowmeter 10; specific wetland plants 7 are planted on the upper part of the main functional area.

Evenly distributed aperture is 1 cm's aperture on the perforation wall 8, aeration pipe 11 set up in 4 inside first quarter section of main functional area and distance system bottom 10cm department, aeration pipe 11's pipe diameter is DN 20mm, and aeration pipe 11 top evenly distributed aperture is 1 mm's aeration hole, and aeration pump 9 carries out intermittent aeration to the system, stops aeration 1 hour per aeration 2 hours, and flowmeter 10 control aeration rate during aeration pipe 9 aeration is 0.5L/min, and the wetland plant type of planting on 4 upper portions of main functional area is Siberian iris.

The working principle is as follows: the simulated sewage is placed in a water distribution barrel, flows into a reactor through a water inlet pipe 1 under the action of a peristaltic pump, flows through a primary sedimentation area 3 through a perforated wall 8 between two areas after passing through a water distribution area 2, flows through a main functional area 4 through the perforated wall after primary sedimentation, is aerated into a system from the bottom of the front end part of the main functional area 4 through an aeration pipe 11 in an intermittent aeration mode by an aeration pump 9, controls the aeration quantity through a flowmeter 10, is subjected to nitrification and denitrification in the area, and then flows into a water collection area 5 and flows out from a water outlet pipe 6.

The COD of the simulated sewage inlet water is 200-300 mg/L, the ammonia nitrogen is 30-40 mg/L, the total nitrogen is 50-60 mg/L, and the total phosphorus is 2.5-3.0 mg/L.

The intermittent aeration mode of the aeration pump is that every 2 hours of aeration is carried out, and the aeration is stopped for 1 hour.

The flow meter controls the aeration rate to be 0.5L/min.

The specific wetland plant 7 planted above the main functional area is Siberian iris.

According to the enhanced denitrification artificial wetland system, the combined measures of bottom aeration of the front end part and planting of Siberian iris have the ammonia nitrogen removal efficiency of 74.9 percent and the total nitrogen removal efficiency of 70.3 percent, and the removal rate of ammonia nitrogen is only 43.0 percent and the removal rate of total nitrogen is 41.8 percent compared with artificial wetland contrast groups which do not aerate and plant canna. Compared with a control group, the enhanced denitrification artificial wetland system has the advantages that the ammonia nitrogen removal rate is improved by 74.2%, the total nitrogen removal rate is improved by 68.2%, and the enhanced denitrification artificial wetland system is a feasible system for improving the ammonia nitrogen and total nitrogen removal effect of the artificial wetland.

While the utility model has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the utility model. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the utility model not be limited to the particular embodiments disclosed, but that the utility model will include all embodiments falling within the scope of the appended claims.

Claims

1. An enhanced denitrification constructed wetland system is characterized by comprising a water inlet pipe (1), a water distribution area (2), a primary sedimentation area (3), a main functional area (4), a water collection area (5) and a water outlet pipe (6) which are sequentially arranged along the water flow direction; perforated walls (8) are adopted outside the primary settling zone (3) and the main functional zone (4); an aerator pipe (11) is arranged at the end part of the front end part of the main functional area (4), and the aerator pipe (11) is connected with an aerator pump (9) through a flowmeter (10); specific wetland plants are planted on the upper part of the main functional area.

2. The enhanced denitrification constructed wetland system according to claim 1, wherein the perforated wall (8) is uniformly distributed with small holes with the diameter of 1 cm.

3. The enhanced denitrification constructed wetland system according to claim 1, wherein the aeration pipe (11) is arranged in the front quarter of the inside of the main functional zone (4) and is 10cm away from the bottom of the system.

4. The enhanced denitrification constructed wetland system according to claim 1, wherein the pipe diameter of the aeration pipe (11) is DN 20 mm.

5. The enhanced denitrification constructed wetland system according to claim 1, wherein aeration holes with the diameter of 1mm are uniformly distributed above the aeration pipe (11).

6. The enhanced denitrification constructed wetland system according to claim 1, wherein the aeration pump (9) performs intermittent aeration on the system, and stops aeration for 1 hour every 2 hours.

7. The enhanced denitrification constructed wetland system according to claim 1, wherein the flow meter (10) controls the aeration rate of the aeration pipe (11) to be 0.5L/min.

8. The enhanced denitrification artificial wetland system according to claim 1, wherein the wetland plant type planted above the main functional zone (4) is Siberian iris.