CN100434373C - A kind of lakeside structural wetland - Google Patents

Abstract

The invention belongs to the technical field of resource environment engineering. The structural wetland in the lakeside zone is composed of the wetland system and its supporting aqueducts and distribution pools. Although the construction and operation costs of structured wetlands are higher, they have higher treatment efficiency and smaller land requirements than natural wetlands; in developing countries with a large number of people and little land and facing huge pressure on sewage discharge, especially economic development The extremely rapid delta area of our country has very broad application prospects.

Description

A kind of lakeside structural wetland

1. Technical field

The invention belongs to the technical field of resources and environment engineering, and relates to a type of wetland construction using local materials.

2. Background technology

Constructed wetlands or treatment wetland systems are man-made, controllable and engineered wetland systems designed and built to improve the physical, chemical and The optimal combination of biological action for wastewater treatment. Although the construction and operation costs of structured wetlands are higher, they have higher treatment efficiency and smaller land requirements than natural wetlands; in developing countries with a large number of people and little land and facing huge pressure on sewage discharge, especially economic development The extremely rapid delta area of our country has very broad application prospects.

The use of structured wetlands to treat sewage can be traced back to 1903. The structured wetlands built in Yorkshire, England, are considered to be the world's first constructed wetlands for sewage treatment. In 1953, the German Max Planck Institute discovered that reeds could remove a large amount of organic and inorganic substances in sewage, and then developed the Max-Planck treatment system. In 1977, Kickuth proposed the "Root-zone Theory", which used the horizontal subsurface flow wetland planted with reeds to degrade organic matter, nitrify and denitrify to remove nitrogen, and precipitate to remove phosphorus, laying the theoretical foundation for structural wetland wastewater treatment. Subsequently, the research on structural wetlands went deep into various components such as substrates, plants, and microorganisms. At the same time, the cross-integration of various disciplines also provided new technologies and ideas for the research of constructed wetlands.

Due to the influence of reclamation from lakes in my country, the lakeside belt with great pollution-cleaning capacity has been completely lost. It is urgent to rebuild and restore its wetland system, or to construct structural wetlands with more outstanding pollution-cleaning capacity.

3. Contents of the invention

The purpose of the present invention is:

Make full use of local resources, invent a lakeside structural wetland treatment system, and improve the pollution removal and control capabilities of the lakeside zone. The structural wetland is composed of the main body of the structural wetland and its supporting aqueducts, distribution channels and distribution pools. The sewage enters the first-level distribution channel through the aqueduct and the distribution tank respectively. The sewage from the distribution channel first enters the structural wetland for treatment, and then falls from the structural wetland to the secondary distribution channel, so that the treated sewage has a short-term gas explosion process; It can degrade SS, COD, TN and TP in sewage.

Technical scheme of the present invention is:

The main vertical section of the structural wetland is trapezoidal: the height on the left is 50 cm, and the height on the right is 20 cm; Thickness 5 cm; cinder layer: particle size 2-3 cm, left thickness 20 cm, right thickness 5 cm; permeable cloth layer: thickness <1 cm; ecological soil layer: mixed by river sand and farmland soil at a ratio of 2:1, Thickness: 10 cm; Vegetation layer: It is composed of bermudagrass and tall fescue in a ratio of 1:1, dotted with a small amount of iris and other flower plants, see attached drawing 1. The base of the structured wetland is a gravel layer with varying thickness, and the size and thickness of the gravel are determined by the terrain conditions.

As supporting facilities for constructing wetlands, it also includes necessary aqueducts, distribution pools and distribution channels, see Figure 2.

Aqueduct: a first-class aqueduct with a bottom width of 50 cm; one side of the canal is next to the embankment of the lake, and only some cleaning work is done; the other side is built with stones with a diameter of 10-20 cm as a retaining dam. The section of the stone dam is trapezoidal: 80 cm high, 20 cm long at the top, and 180 cm long at the bottom. The bottom of the canal is a 20 cm gravel layer with a diameter of 10-20 cm. Lay permeable cloth on the slope and top of the dam, and lay 10 cm of ecological soil, the ecological soil is composed of sand: soil=2:1. Bermudagrass and tall fescue plants are planted on the ecological soil surface to form a vegetation layer. See attached picture 3. Secondary aqueduct with a width of 50 cm, see attached drawing 2. The base of the canal is a 10 cm gravel layer. One side of the canal is a structural wetland, and the other side is a stone dam. The height of the stone dam is 30 cm, and it is made of stones with a diameter of 10-20 cm. The section of the dam is trapezoidal: the upper side is 20 cm long and the bottom side is 60 cm long. Lay permeable cloth on the slope and top of the dam, and lay 10 cm of ecological soil, and plant bermudagrass and tall fescue plants on the surface of the ecological soil to form a vegetation layer, see Figure 4.

Distribution pool: located between the aqueduct and the distribution canal, a cylindrical body with a bottom side length of 50 cm, see attached drawing 2. The height of the connection with the first-level aqueduct is 30 cm, the height of the connection with the second-level aqueduct is 40 cm, the height of the connection with the aqueduct is 50 cm, and the height of the remaining side is 80 cm. It is made of cement board with a thickness of 5 cm. The outside of the 80 cm side is built with stones to form a trapezoidal slope; the slope is trapezoidal, with an upper side of 20 cm and a lower side of 180 cm. Lay permeable cloth on the top and slope of the trapezoid, and lay 10 cm of ecological soil, and plant bermudagrass and tall fescue plants on the surface of the ecological soil to form a vegetation layer. The outer measurement of the other three sides is built with stones to form a slope, and its section is an isosceles triangle, which plays a role in fixing the cement board, see attached drawing 5.

Distribution channel: a first-class distribution channel with a bottom width of 50 cm, see Attachment 2. On one side of the canal is the embankment of Taihu Lake. On the other side, the stone dam is 40 cm high. The section of the dam is trapezoidal: the upper side is 20 cm long and the bottom side is 50 cm long. Its outside is a structural wetland. The bottom of the canal is 20 centimeters of gravel, and the diameter of the gravel is 10-20 centimeters, see accompanying drawing 6. Secondary distribution channel, width 30 cm, see attached drawing 2. One side of the canal is the edge of the structural wetland, with a height of 20 cm; the other side is a 15 cm permeable dam built with stones. The section of the dam is trapezoidal. cm, see Figure 6.

Effect of the present invention is:

Make the treated sewage have a short-term gas explosion process. The sewage from the secondary distribution channel freely enters the reed wetland in the lakeside belt, flows on the surface of the reed wetland, and undergoes further degradation. After the wetland treatment, the removal rates of SS, COD, TN and TP in the sewage are 75%-95%, 25%-55%, 25-45% and 25%-50%, respectively.

4. Description of drawings

Fig. 1 Design drawing of lakeside structural wetland reconstruction project. ① First-level distribution channel, ② Second-level distribution channel, ③ Gypsum layer, ④ Cinder layer, ⑤ Pervious cloth, ⑥ Ecological soil layer, ⑦ Vegetation layer; measurement unit: cm.

二级导水渠，

构造湿地，测量单位：厘米。Figure 2 Plane distribution design drawing of aqueduct, distribution tank and distribution channel. ①.First-level distribution channel, ②Secondary distribution channel; ⑧Fairway, ⑨First-level aqueduct, ⑩Distribution pool

secondary aqueduct,

Constructed wetlands, measurement unit: cm.

防波堤，

砾石层，

砾石坝；测量单位：厘米。Figure 3 Design drawing of the vertical section of the first-level aqueduct. ⑤ permeable cloth, ⑥ ecological soil layer ⑦ vegetation layer, ⑨ primary aqueduct,

breakwater,

gravel layer,

Gravel dam; unit of measurement: cm.

二级导水渠，

构造湿地，

砾石层，测量单位：厘米。Figure 4 Design drawing of the vertical section of the secondary aqueduct. ⑤ permeable cloth; ⑥ ecological soil layer, ⑦ vegetation layer on the canal bank,

secondary aqueduct,

constructed wetlands,

Gravel layer, measured in centimeters.

二级导水渠；

砾石坝，水泥挡板，测量单位：厘米。Figure 5 is the vertical section design drawing of the water distribution tank. ① first-level distribution channel, 10 distribution pools, ⑤ water-permeable cloth, 6 ecological soil layers, ⑦ vegetation layer, ⑨ first-level aqueduct,

secondary aqueduct;

gravel dam, Cement baffle, measurement unit: cm.

构造湿地，

防波堤，

砾石层，砾石坝，

芦苇湿地功能区；测量单位：厘米。Fig. 6 Vertical section design drawing of primary and secondary distribution channels. ① First-level distribution channel, ② Second-level distribution channel, ③ Gypsum layer, ④ Cinder layer, ⑤ Pervious cloth, ⑥ Ecological soil layer, ⑦ Structural wetland vegetation layer, ⑦ Canal bank vegetation layer,

constructed wetlands,

breakwater,

gravel layer, gravel dam,

Functional area of reed wetland; measurement unit: cm.

Description of drawings

二级导水渠，

构造湿地，

防波堤，

砾石层，

砾石坝，

水泥挡板，芦苇湿地功能区。The unified numbers are: ① first-level distribution channel, ② second-level distribution channel, ③ gypsum layer, ④ cinder layer, ⑤ permeable cloth, ⑥ ecological soil layer, ⑦ vegetation layer; ⑧ waterway, ⑨ first-level aqueduct, ⑩ distribution pool,

secondary aqueduct,

constructed wetlands,

breakwater,

gravel layer,

gravel dam,

cement baffle, Reed wetland functional area.

5. Specific implementation

This method is carried out in the lakeshore zone in the west of Taihu Lake, with an area of 2500m ² . Its implementation works as follows:

The first step is to inspect the site, determine the plan, and carry out engineering design according to the site conditions; implement the seedlings and construction materials of ecological tool species, and organize engineering and technical personnel in place.

The second step is to focus on infrastructure projects. The terrain in the construction area is uneven, and a large amount of garbage has been scattered and accumulated; the site needs to be cleaned up before the project is implemented; the first and second aqueducts, distribution pools, first and second distribution canals, and structural wetlands will be built.

The third step is to focus on biological restoration engineering. In primary and secondary aqueducts, distribution tanks, secondary aqueducts, constructed wetlands, sowing or transplanting required plants.

The fourth step is on-site operation and effect monitoring.

Finally, because plants have a certain mortality rate and are impacted by lake water waves, after the completion of the project, proper management and maintenance of plant tool species must be carried out; large rocks must also be used in places where structural wetlands have suffered greater impacts. Protect.

Claims (2)

1. A structural wetland in the lakeside zone, characterized in that the constructed wetland is composed of a structural wetland main body and its supporting aqueduct, a water distribution tank and a water distribution channel, and sewage enters the structural wetland through the aqueduct, a water distribution tank and a primary distribution channel The main body is treated, and then dropped from the structural wetland to the secondary distribution channel for aeration; the vertical section of the structural wetland main body is trapezoidal, divided into 5 layers, from the lower layer to the upper layer: waste gypsum layer, cinder layer, permeable cloth layer, Ecological soil layer and vegetation layer; waste gypsum layer: particle size 2-3 cm, left thickness 20 cm, right thickness 5 cm; cinder layer: particle size 2-3 cm, left thickness 20 cm, right thickness 5 cm; permeable cloth Layer: thickness < 1 cm; ecological soil layer: composed of river sand and farmland soil at a ratio of 2:1, thickness 10 cm; vegetation layer: composed of bermudagrass and tall fescue at a ratio of 1:1; aqueducts and distribution channels and the distribution pool are composed of gravel layer, permeable cloth layer, ecological soil and vegetation layer; the thickness of the gravel layer of the aqueduct and the primary distribution channel is 20 cm, and the diameter of the gravel is 10-20 cm. The 5 cm gravel layer of the secondary distribution channel consists of a diameter of Small boulders < 5 cm. 2. The application of the structured wetland in the lakeside zone according to claim 1, characterized in that it can treat sewage from rivers entering the lake and water bodies of the lake.

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