SYSTEM AND METHOD FOR RESTORING WATER ENVIRONMENT BY A CONSTRUCTED WETLAND

Abstract

The disclosure relates to the field of water environment treatment, and more particularly to a system and a method for restoring a water environment by a constructed wetland. The system for restoring the water environment by the constructed wetland includes: (1) a water distribution pipe for inputting a water body to be treated into the constructed wetland; (2) a magnetization reactor arranged around the water distribution pipe and used for applying a magnetic field perpendicular to the water flow direction to the water body flowing through the water distribution pipe in order to make the water body entering the constructed wetland through the water distribution pipe become magnetized water after magnetization treatment; (3) the constructed wetland; (4) a magnetization reactor arranged in the vertical direction of the constructed wetland and used for applying a magnetic field to the constructed wetland in the vertical direction; and (5) a water outlet pipe used for discharging the water body treated by the constructed wetland. The water body to be treated passes through the water distribution pipe, is treated by the magnetization reactor arranged around the water distribution pipe and then enters the constructed wetland. Meanwhile, the magnetization reactor arranged in the vertical direction of the constructed wetland is used for intermittently magnetizing the constructed wetland, so that the technical problems of high blocking possibility during operation and difficult rapid restoration of the constructed wetland can be effectively solved.

Claims

1. A system for restoring a water environment by a constructed wetland, comprising: a water distribution pipe for inputting a water body to be treated into the constructed wetland; a magnetization reactor arranged around the water distribution pipe and used for applying a magnetic field perpendicular to the water flow direction to the water body flowing through the water distribution pipe in order to make the water body entering the constructed wetland through the water distribution pipe become magnetized water after magnetization treatment; a magnetization reactor arranged in the vertical direction of the constructed wetland and used for applying a magnetic field to the constructed wetland in the vertical direction; and a water outlet pipe used for discharging the water body treated by the constructed wetland.

2. The system according to claim 1, wherein the upper and bottom portions of the constructed wetland are filled with a filler with a diameter of 15-50 mm, and plants are planted in the upper portion, and the middle portion is filled with a mixture of a filler with a diameter of 5-15 mm and iron filings, with the ratio of the iron filings to the filler being 1:3-1:8.

3. The system according to claim 2, wherein the plants planted in the upper portion of the constructed wetland are emergent plants, which can be selected from one or more of Typha angustifolia, Nelumbo nucifera, bowl lotus, Phragmites australis, Typha orientalis Presl, Zizania latifolia, Arundo donax, Phyllostachys heteroclada, Schoenoplectus tabernaemontani, Acorus calamus, Cortaderia selloana, Sparganium stoloniferum, etc.

4. A method for restoring a water environment by a constructed wetland, comprising: inputting, using a water distribution pipe, a water body to be treated into the constructed wetland; applying, using a magnetization reactor arranged around the water distribution pipe, a magnetic field perpendicular to the water flow direction to the water body flowing through the water distribution pipe to make the water body enter the constructed wetland through the water distribution pipe become magnetized water after magnetization treatment; applying, using a magnetization reactor arranged in the vertical direction of the constructed wetland, a magnetic field to the constructed wetland in the vertical direction; and discharging, using a water outlet pipe, the water body treated by the constructed wetland, wherein the water body to be treated passes through the water distribution pipe, is treated by the magnetization reactor arranged around the water distribution pipe, wherein the water body to be treated passes through the water distribution pipe and then enters the constructed wetland; and magnetizing the constructed wetland by the magnetization reactor arranged in the vertical direction of the constructed wetland.

5. The method according to claim 4, wherein the intensity of the magnetic field for magnetizing the water body in the water distribution pipe is 50 mT-1500 mT, and the magnetization time is 1 min-120 min.

6. The method according to claim 5, wherein the intensity of the magnetic field for magnetizing the water body in the water distribution pipe is 100 mT-250 mT, and the water flow speed is 0.2 m/min-10 m/min.

7. The method according to claim 4, wherein the intensity of the magnetic field for intermittently magnetizing the constructed wetland is 30 mT-800 mT, the time for single magnetization is 5 min-300 min, and the interval time is 3 h-240 h.

8. The method according to claim 7, wherein the intensity of the magnetic field for intermittently magnetizing the constructed wetland is 50 mT-100 mT, the time for single magnetization is 30 min-45 min, and the interval time is 24 h-72 h.

9. The method according to claim 4, wherein the water body to be treated is a water body with water quality of class II-V.

10. The system according to claim 1, wherein the system is placed in the water environment treatment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 is a schematic diagram of a structure of the system for restoring a water environment by a constructed wetland according to the disclosure.

[0038] In the FIGURE: 1: a magnetization reactor (for magnetizing the water body in a water distribution pipe), 2: a magnetization reactor (for magnetizing a constructed wetland), 3: the water distribution pipe, 4: a water outlet pipe, and 5: the constructed wetland.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The preferred implementation modes of the disclosure will be further described in detail hereafter with reference to embodiments. It should be understood that the following embodiments are given for illustrative purposes only and are not intended to limit the scope of the disclosure. Those skilled in the art can make various modifications and substitutions to the disclosure, without departing from the tenets and spirit of the disclosure.

[0040] The experimental methods used in the following embodiments are conventional methods, unless otherwise specified.

[0041] The materials, reagents, etc. used in the following embodiments are commercially available, unless otherwise specified.

Embodiment 1

[0042] In the laboratory, the constructed wetland constructed by the method of the disclosure may be simulated, and the constructed wetland models numbered A, B, C, D, E and F may be selected. Each of the constructed wetlands had a covering area of 3200 cm.sup.2, and the reactor may be 80 cm long, 40 cm wide and 40 cm high. The left and right sides of the reactor may be respectively provided with a water distribution pipe and a water outlet pipe both with a diameter of 100 mm, the water flow speed may be 0.5 m/min, and the time for passing through the water distribution pipe may be 5 min. The reactors A, D, and F may be respectively electromagnetic magnetization reactors with a magnetic field intensity of 100 mT arranged around the water distribution pipes, and an electromagnetic magnetization reactor with a magnetic field intensity of 50 mT may be arranged in the vertical direction of the water flow in the constructed wetland model; the reactor B may be an electromagnetic magnetization reactor with a magnetic field strength of 100 mT arranged around the water distribution pipe; the reactor C may be an electromagnetic magnetization reactor with a magnetic field strength of 50 mT arranged in the vertical direction of water flow in the constructed wetland model; the reactor E may be an electromagnetic magnetization reactor with a magnetic field strength of 100 mT arranged around the water distribution pipe, and an electromagnetic magnetization reactor with a magnetic field strength of 30 mT may be arranged in the vertical direction of the water flow in the constructed wetland model.

[0043] In the constructed wetland reactor, the 1/3 sections of the upper and bottom portions may be filled with detritus with a diameter of 30 mm; the middle portion may be filled with a mixture of coarse sand and iron filings with a diameter of 25 mm, with the ratio of the iron filings to the coarse sand being 1:5. Typha angustifolia and Schoenoplectus tabernaemontani may be planted in the upper portion of the reactor of the constructed wetland at the planting ratio of 1:1. The water body entering the water distribution pipe may be controlled to have a COD concentration of 80 mg/L, a TN concentration of 10 mg/L and an ammonia nitrogen concentration of 10 mg/L.

[0044] When water flowed into reactors A and E, the magnetization reactor may be turned on until the inflow of water may be completed, wherein the intermittent magnetization period may be 24 h, the magnetization time may be 30 min, and the magnetization may be continuously operated for 6 months. When water flowed into reactor B, the magnetization reactor may be turned on until the inflow of water may be completed, intermittent magnetization may be not performed, and the magnetization may be continuously operated for 6 months. No magnetization may be conducted when water flowed into reactor C, and when the inflow of water may be completed, intermittent magnetization may be conducted, wherein the intermittent magnetization period may be 24 h, the magnetization time may be 30 min, and the magnetization may be continuously operated for 6 months. When water flowed into reactor D, the magnetization reactor may be turned on until the inflow of water may be completed, wherein the intermittent magnetization period may be 72 h, the magnetization time may be 30 min, and the magnetization may be continuously operated for 6 months. When water flowed into the reactor F, the magnetization reactor may be turned on until the inflow of water may be completed, wherein the magnetization of the constructed wetland may be conducted for 6 months. It is to be noted that the constructed wetland using reactor A operated at a good state, without blockage in 6 months, with smooth drainage and good removal efficiency; the constructed wetlands using reactors B and F may be slightly blocked at 4 months, and seriously blocked at 6 months, with poor removal efficiency; the constructed wetlands using reactors C, D and E operated at a general state, and may be slightly blocked at 6 months, with a relatively good removal efficiency.

TABLE-US-00001 TABLE 1 Time A B C D E F Magnetization reactor for Turn Turn on Not Turn Turn on Turn on the inlet water on turn on on Intensity of the magnetic 100 100 0 100 100 100 field of the inlet water Intermittent magnetization Turn Not turn on Turn Turn Turn on Continuous by the reactor on on on magnetization Magnetization intensity of 50 0 50 50 30 50 the reactor (mT) Magnetization action time 30 0 30 30 30 6 months of the reactor/min Magnetization cycle of 24 0 24 72 24 6 months the reactor/h % COD removal rate at 2 94.7 52.3 78.6 85.3 86.7 53.4 months % TN removal rate at 2 97.3 55.9 73.4 88.5 89.4 55.7 months % ammonia nitrogen 96.5 53.5 76.9 86.4 85.1 52.7 removal rate at 2 months % COD removal rate at 4 95.6 49.6 77.5 86.3 85.4 54.0 months % TN removal rate at 4 96.9 50.7 76.3 83.9 85.5 54.7 months % ammonia nitrogen 97.3 52.4 74.1 84.7 84.8 51.4 removal rate at 4 months % COD removal rate at 6 95.2 45.3 75.7 82.5 83.2 50.2 months % TN removal rate at 6 98.2 44.5 72.4 85.6 84.1 50.8 months % ammonia nitrogen 95.6 48.5 71.7 83.2 85.0 49.7 removal rate at 6 months Initial permeability 0.1 0.1 0.1 0.1 0.1 0.1 coefficient of the filler (m/s) Permeability coefficient 0.07 0.001 0.01 0.03 0.02 0.001 of the filler at 4 months (m/s) Permeability coefficient 0.06 0.0006 0.005 0.008 0.009 0.0007 of the filler at 6 months (m/s)

Embodiment 2

[0045] In a certain city, experimental constructed wetlands A, B, C, D, E, and F may be constructed by the method of the disclosure. Each of the constructed wetlands had a covering area of 64 m.sup.2, and may be 8 m long, 8 m wide and 3 m high. The left and right sides of the constructed wetland may be respectively provided with a water distribution pipe and a water outlet pipe both with a diameter of 500 mm, the water flow speed may be 2.5 m/min, and the time for passing through the water distribution pipe may be 20 min. The experimental constructed wetlands A, D and F may be respectively provided with electromagnetic magnetization reactors with a magnetic field intensity of 250 mT arranged around the water distribution pipes, and an electromagnetic magnetization reactor with a magnetic field intensity of 100 mT may be arranged in the vertical direction of the water flow in the constructed wetland model; the experimental constructed wetland B may be provided with an electromagnetic magnetization reactor with a magnetic field strength of 250 mT arranged around the water distribution pipe; the experimental constructed wetland C may be provided with an electromagnetic magnetization reactor with a magnetic field strength of 100 mT arranged in the vertical direction of water flow; the experimental constructed wetland E may be provided with an electromagnetic magnetization reactor with a magnetic field strength of 250 mT arranged around the water distribution pipe, and an electromagnetic magnetization reactor with a magnetic field strength of 50 mT may be arranged in the vertical direction of the water flow.

[0046] In the constructed wetland, the 1/3 sections of the upper and bottom portions may be respectively filled with gravel with a diameter of 50 mm; the middle portion may be filled with a mixture of zeolite and iron filings with a diameter of 30 mm, with the ratio of the iron filings to the zeolite being 1:4. Acorus calamus and Phragmites australis may be planted in the upper portion of the constructed wetland at the planting ratio of 1:2. The water body entering the water distribution pipe may be controlled to have a COD concentration of 200 mg/L, a TN concentration of 30 mg/L, and an ammonia nitrogen concentration of 40 mg/L.

[0047] When water flowed into reactors A and E, the magnetization reactors may be may be turned on until the inflow of water may be completed, wherein the intermittent magnetization period may be 72 h, the magnetization time may be 45 min, and the magnetization may be continuously operated for 1 year. When water flowed into the reactor B, the magnetization reactor may be turned on until the inflow of water may be completed, intermittent magnetization may be not performed, and the magnetization may be continuously operated for 1 year. No magnetization may be conducted when water flowed into reactor C, and when the inflow of water may be completed, intermittent magnetization may be conducted, wherein the intermittent magnetization period may be 72 h, the magnetization time may be 45 min, and the magnetization may be continuously operated for 1 year. When water flowed into reactor D, the magnetization reactor may be turned on until the inflow of water may be completed, wherein the intermittent magnetization period may be 144 h, the magnetization time may be 45 min, and the magnetization may be continuously operated for 1 year. When water flowed into the reactor F, the magnetization reactor may be turned on until the inflow of water may be completed, wherein the magnetization of the constructed wetland may be conducted for 1 year. It could be seen that the constructed wetland using the reactor A operated at a good state, without blockage in 1 year, with smooth drainage and good removal efficiency; the constructed wetlands using reactors B and F may be slightly blocked at 5 months, and seriously blocked at 1 year, with poor removal efficiency; the constructed wetlands using reactors C, D and E operated at a general state, and may be slightly blocked at 1 year, with a relatively good removal efficiency.

TABLE-US-00002 TABLE 2 Time A B C D E F Magnetization reactor for Turn Turn on Not Turn Turn on Turn on the inlet water on turn on on Intensity of the magnetic 250 250 0 250 250 100 field of the inlet water Intermittent magnetization Turn Not Turn Turn Turn on Continuous by the reactor on turn on on on magnetization Magnetization intensity of 100 0 100 100 50 100 the reactor (mT) Magnetization action time 45 0 45 45 45 1 year of the reactor/min Magnetization cycle of 72 0 72 144 72 1 year the reactor/h % COD removal rate at 4 88.6 32.3 70.3 77.9 80.4 30.5 months % TN removal rate at 4 89.0 39.5 71.6 78.4 79.4 31.7 months % ammonia nitrogen 92.6 37.6 72.2 76.1 75.1 33.4 removal rate at 4 months % COD removal rate at 8 89.3 30.7 70.7 75.4 78.7 30.1 months % TN removal rate at 8 88.2 36.5 70.4 73.9 79.8 29.7 months % ammonia nitrogen 88.8 38.2 70.1 74.7 76.3 30.6 removal rate at 8 months % COD removal rate at 86.4 30.5 69.2 74.4 79.4 27.8 12 months % TN removal rate at 12 87.7 34.1 69.9 72.0 77.6 28.8 months % ammonia nitrogen 87.8 30.0 70.1 71.9 74.3 27.5 removal rate at 12 months Initial permeability 0.1 0.1 0.1 0.1 0.1 0.1 coefficient of the filler (m/s) Permeability coefficient 0.05 0.0009 0.02 0.03 0.03 0.0008 of the filler at 5 months (m/s) Permeability coefficient 0.04 0.0001 0.001 0.004 0.005 0.0001 of the filler at 12 months (m/s)

[0048] Although the disclosure has been described in detail with general description and specific embodiments hereinabove, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the disclosure. Therefore, all such modifications or improvements made without departing from the spirit of the disclosure are within the claimed scope of the disclosure.