CN111762898B - Ecological gravel revetment for degrading micro-pollutants in water body and construction method thereof - Google Patents

Abstract

The invention relates to an ecological gravel revetment for degrading micro-pollutants in a water body and a construction method thereof, relates to the field of hydraulic engineering, and solves the problem of river pollution. Ecological gravel revetment includes: gravel structures, biological bags and vegetation boards; the biological bags are arranged on the outer surface of the gravel structure; the vegetation board is arranged on the outer surface of the gravel structure outside the biological bag arrangement area. The technical scheme provided by the invention can maintain the ecological function and self-cleaning capability of the river channel.

Description

Ecological gravel revetment for degrading micro-pollutants in water body and construction method thereof

Technical Field

The invention relates to the field of hydraulic engineering, in particular to an ecological gravel revetment for degrading micro-pollutants in a water body and a construction method thereof.

Background

With the gradual slowing of the urbanization process, the national development transformation and upgrade of the urban river provide new requirements for ecological restoration of the urban river. Therefore, the ecological restoration of the urban rivers in the system is the trend of the urban development.

The river revetment is an important component in a river ecosystem structure and is extremely important for restoring the overall ecological structure and ecological functions of the river.

The existing river channel revetments are mostly from the view angle, and in addition, people often neglect the specific conditions of a water system due to water conservancy requirements, and directly build the revetments by adopting a hardening and straightening mode, so that the natural form of the water system is damaged, the biodiversity of two banks of the river channel is seriously damaged, and the ecological function and the self-cleaning capability are lost. For example, various nutrient-rich substances such as N, P, harmful substances such as heavy metals and organic pollutants such as COD and BOD cannot be effectively degraded, so that the water body is seriously eutrophicated, and the water system pollution is further aggravated.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide an ecological gravel revetment for degrading micro-pollutants in water and a construction method thereof, which can maintain the ecological function and self-cleaning capability of a river.

In a first aspect, an embodiment of the present invention provides an ecological gravel revetment for degrading micro-pollutants in a water body, including: gravel structures, bio-bags and vegetation boards;

the bio-bag is disposed on an outer surface of the gravel structure;

the vegetation board is arranged on the outer surface of the gravel structure outside the biological bag arrangement area; the biological bag comprises a zeolite structure, beneficial microorganisms and nutrients of the beneficial microorganisms, and the beneficial microorganisms and the nutrients of the beneficial microorganisms are adsorbed in the zeolite structure to form a biological film on the surface of the zeolite.

Further, the outer surface of the gravel structure has a concave-convex structure.

Further, the gravel structure comprises a plurality of gravel units, and adjacent gravel units are staggered to form a concave-convex structure on the outer surface of the gravel structure.

Further, the rugged structure is located at a lower portion of the gravel structure.

Further, the vegetation board includes: carrying plate, planting matrix and vegetation;

the vegetation is planted on the planting substrate;

the carrier plate carries the planting substrate.

Further, the vegetation board is hinged to the top surface of the gravel unit.

Further, the vegetation board with the top surface of gravel unit passes through the connector link and articulates, the connector link sets up vegetation board bottom, connect the top surface of gravel unit with the bottom surface of vegetation board.

Further, the top surface of gravel unit is the inclined plane, the vegetation board with the inclined plane butt of gravel unit, the top surface of gravel unit the top surface border with the bottom surface border of vegetation board passes through the connector link is articulated, other limits of the bottom surface of vegetation board are the free state, and when vegetation board immerses in the water, vegetation board floats.

Further, the biological bag is one or more of an aerobic biological bag, a facultative biological bag and an anaerobic biological bag.

In a second aspect, an embodiment of the present invention provides a construction method of an ecological gravel revetment for degrading micro-pollutants in a water body, including the following steps:

(1) leveling the surface of the shoreline to obtain a leveled shoreline base;

(2) laying a plurality of layers of net cages in gradient distribution on the shore line base, wherein one or more layers of net cages at the bottom form a concave-convex structure;

(3) placing gravel in each net cage to form gravel units;

(4) respectively arranging biological bags on the outer surfaces of the gravel units according to the river water level; the biological bag comprises a zeolite structure, beneficial microorganisms and nutrients for the beneficial microorganisms, the beneficial microorganisms and the nutrients for the beneficial microorganisms being adsorbed in the zeolite structure;

(5) and installing a vegetation plate on the outer surface of the gravel unit outside the biological bag arrangement area.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

1. the method is characterized in that microbes and nutrients in the biological bags are utilized to construct dominant floras near the revetment, and the mobility of river water is utilized to diffuse the dominant floras to the whole river, so that the ecological function of the whole river is improved, and the self-cleaning capacity of the whole river is improved.

2. The grass on the vegetation plate is utilized to create a good and relatively stable growing environment for microorganisms in the river and microorganisms in the biological bags, so that the ecological function of the whole river and the self-cleaning capability of the whole river are maintained.

3. The concave-convex structure is constructed on the contact surface of the revetment and the river water so as to increase the turbulence degree of the river water at the contact surface, thus not only increasing the oxygen content of the river water at the contact surface and being beneficial to the growth of microorganisms, but also promoting the material circulation among all layers of the river water, thereby improving the ecological function and the self-purification capacity of the whole river. In addition, the dominant flora near the revetment is also favorable for diffusing to the whole river.

4. The top surface of the gravel unit is designed into an inclined plane, and the vegetation board is hinged to the gravel unit by utilizing the annular connecting buckle, so that the vegetation board can float on the river surface when the water level of the river rises, and the grass vegetation river in the vegetation board is prevented from being submerged.

5. According to different water levels, the aerobic biological bag, the facultative biological bag and the anaerobic biological bag are correspondingly configured, so that the microorganisms in the biological bags are prevented from being reduced in reproduction rate and even killed on a large scale due to environmental discomfort.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic view of a gravel pack according to the present invention;

FIG. 2 is a schematic illustration of a gravel construction provided by the present invention;

FIG. 3 is a schematic view of the relationship between the river water level and the vegetation board provided in the present invention;

FIG. 4 is a schematic diagram of the structure of zeolite provided by the present invention;

fig. 5 is a flow chart of the construction method of the ecological gravel revetment for degrading micro-pollutants in the water body provided by the invention.

Reference numerals are as follows: 1-a gravel unit; 11-a top surface; 12-side; 2-vegetation board; 3-biological bag; 4-connecting buckles; 21-planting matrix; 22-vegetation; 31-aerobic bio-bags; 32-facultative biological bag; 33-anaerobic biological bags; 34-zeolite structure; 35-beneficial microorganisms and nutrients for beneficial microorganisms.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention and not to limit its scope.

The invention discloses an ecological gravel revetment for degrading micro-pollutants in a water body, and as shown in figures 1 and 2, gravel units 1 form a gravel structure, the gravel structure is a revetment main body supporting structure, and a biological bag and a vegetation plate are carried on the gravel structure. The gravel structure comprises two parts, one part is immersed in the river and is an immersed part, the other part is not immersed in the river and is a non-immersed part, wherein the immersed part is the lower part of the gravel structure, the upper part of the gravel structure of the non-immersed part is shown in figure 2, the bottommost two layers of gravel units 1 form the immersed part, and the rest is the non-immersed part. The immersion portion and the non-immersion portion are relative concepts, and the division of the two portions is related to the water level only. Embodiments of the present invention divide the submerged and non-submerged portions by normal water level, without regard to extremes such as water level rises caused by flooding or other irresistibility forces. As shown in fig. 2, the gravel unit at the lower part constructs a plurality of concave-convex structures on the outer surface of the gravel structure, wherein the gravel unit is a convex structure, and the gap between two adjacent convex structures is a concave structure. Illustratively, the gravel units of adjacent bottom parts are arranged in a staggered manner, so that a plurality of concave-convex structures are formed, and the actual shapes and sizes of the structures are related to the adopted gravel. The quantity of concave-convex structure should not be too big or undersize, should keep 10 ~ 30/10 m to guarantee the immersion portion tortuosity of revetment, make the river striking can produce better torrent effect when the immersion portion. Meanwhile, in the concave structure, the included angle between the opposite surfaces of the two gravel units is not less than 120 degrees, and a dead water area is avoided being caused artificially.

In the present embodiment, the vegetation plates 2 may be provided on both the lower portion of the gravel structure, such as aquatic plants, and the upper portion of the gravel structure, such as terrestrial plants. Specifically, as shown in fig. 2, the gravel unit 1 includes a top surface 11 and a side surface 12, and as terrestrial plants, such as vines, the gravel unit 1 may be disposed at the top surface 11 and the side surface 12 of the gravel structure. The aquatic plants may be provided on the top surface 11 and the side surface 12 of the gravel pack 1 which is entirely immersed in the river water, or on the side surface 12 of the gravel pack 1 which is partially immersed in the river water. Through the mode, the greening rate of the revetment can be improved to the greatest extent. The vegetation sheet 2 includes: planting substrate 21, vegetation 22 and a carrier plate. Wherein vegetation 22 is planted on planting substrate 21. The carrier plate carries the planting substrate 21 and is hinged to the top surface 11 of the gravel unit by a connector link. The carrier plate forms the bottom surface of the vegetation plate 2, and shields the planting base 21 and the vegetation 22, and thus cannot be shown in the figure.

The vegetation in the embodiment of the invention selects the shallow root system grass for planting, the length of the root system is between 10 and 25cm, and the roots of the shallow root system grass for planting are used for providing living environment for microorganisms in the biological bags and microorganisms in water.

The planting substrate 21 of the embodiment of the invention is formed by mixing common garden soil, drainage materials, light aggregate, humus soil and the like, and can effectively reduce the pressure borne by the revetment while ensuring the growth demand of vegetation.

The method specifically comprises the following steps: the common garden soil comprises (11-16) of humus soil, 4-8 of lightweight aggregate, 12-18 of vermiculite and 1-2 of lightweight aggregate.

Preferably, the ratio of common garden soil, humus soil, lightweight aggregate and drainage material is 14:5:14: 1.

Wherein, the components of the common garden soil are 0.6 to 1 percent of organic matter, 0.05 to 0.075 percent of nitrogen, 0.0003 to 0.0005 percent of phosphorus, 0.03 to 0.005 percent of potassium, 15 to 17 percent of humus soil, 0.5 to 1.5 percent of nitrogen, 0.2 to 0.5 percent of phosphorus and 0.2 to 0.5 percent of potassium. The lightweight aggregate is mainly made of natural materials such as pumice, scoria and the like. The particle size of the vermiculite is 3-6 mm.

The carrying plate of the embodiment of the invention can be connected with the top surface 11 of the gravel unit 1 through the connecting buckle 4 arranged at the bottom end of the vegetation plate 2. When the top surface 11 is horizontal, the connector links 4 are only used to secure the vegetation board 2 to the gravel unit 1. When the top surface 11 is the inclined plane, the connector 4 is the annular so that the top edge of the top surface 11 of the gravel unit is hinged with the top edge of the bottom surface of the vegetation plate through the connector, and other edges of the bottom surface of the vegetation plate are in free states. Since the planting substrate 21 is made of a material having a low density and the bottom surface of the vegetation plate 2 is hinged to the top surface 11 of the gravel unit 1, when the water level of the river rises, the buoyancy of the river floats the vegetation plate 2 so that the vegetation 22 is not submerged by the river, as shown in fig. 3. The main body of the object carrying plate is of a water permeable structure or made of water permeable materials, so that the seepage of redundant water is facilitated, and the root system of vegetation is prevented from being rotten.

In the embodiment of the present invention, the bio-bag 3 contains a plurality of microbes for purifying water quality, and may be disposed in the immersion portion so as to maintain the microbial diversity of the river. The biological bag 3 comprises: zeolite structure 34, beneficial microorganisms and nutrients 35 for the beneficial microorganisms. As shown in fig. 4, beneficial microorganisms and beneficial microorganism nutrients 35 are adsorbed in the zeolite structure 34, the beneficial microorganism nutrients providing nutrients for the growth of the beneficial microorganisms. For a gravel unit 1 completely immersed in river water, a bio-bag 3 may be provided on both the top surface 11 and the side surface 12 of the gravel unit. The zeolite structure is specifically: the particle is not less than 200 meshes, and the specific surface area is not less than 300m ² The density of the mixture is 1.8 to 2.2g/cm ³ Hydrochloric acid solubility is less than or equal to 0.1 percent, NH ⁴⁺ The exchange capacity is more than or equal to 15mg/100 g. The zeolite is a natural environment mineral material, has the characteristics of high porosity, large specific surface area, ion exchange property, adsorptivity, catalysis property and the like, when the zeolite is contacted with surface water, gaps of the zeolite can be used as propagation carriers of microorganisms, the adsorptivity of the zeolite can adsorb organic pollutants in water to the surface and can be degraded to be harmless by the microorganisms, and meanwhile, the zeolite is harmless to NH ⁴⁺ The adsorption of the method can effectively reduce the ammonia nitrogen content in water and solve the problem of water eutrophication.

In the embodiment of the present invention, as shown in fig. 1, the bio bags may be classified into aerobic bio bags 31, facultative bio bags 32 and anaerobic bio bags 33 according to the kind of flora in the bio bags 3. The oxygen demand of the microorganisms is ranked from large to small as aerobic organisms, facultative organisms and anaerobic organisms. Generally, the closer to the water surface, the higher the oxygen content in the water. However, the water surface is fluctuating and cannot be quantified, so the water level is used to represent the distance from the water surface. The basic water level of the river is taken as the water surface, and the basic water level of the river can be obtained through hydrological data, such as the average water level of the last five years. Thus, the water level corresponding to the pair of aerobic bio-bags 31 is higher than the water level corresponding to the facultative bio-bag 32, and the water level corresponding to the facultative bio-bag 32 is higher than the water level of the anaerobic bio-bag 33. The positions of the aerobic bio-bag 31, the facultative bio-bag 32 and the anaerobic bio-bag 33 on the gravel unit 1 are shown in fig. 1.

It should be noted that fig. 1 shows only one arrangement of aerobic bio-bags 31, facultative bio-bags 32 and anaerobic bio-bags 33. For the lowermost gravel unit 1, its sides 12 will typically be provided with a facultative biological bag 32 and an anaerobic biological bag 33, or even only an anaerobic biological bag 33. For river reach with periodically changing water level, the arrangement mode of the biological bags 3 is not fixed. For example, the location where the anaerobic bio-bag 33 was originally placed may need to be replaced with aerobic bio-bag 31 or facultative bio-bag 32 when precipitation is low, and similarly, the location where the anaerobic bio-bag 33 was originally placed may need to be replaced with aerobic bio-bag 31 or facultative bio-bag 32 when precipitation is high. It can be seen that, in the embodiment of the present invention, the aerobic bio-bag 31, the facultative bio-bag 32 and the anaerobic bio-bag 33 can be flexibly configured, thereby further maintaining the self-cleaning capability of the river.

Therefore, the gravel revetment provided by the invention can maintain and improve the ecological environment of rivers in multiple dimensions.

Firstly, beneficial microorganisms and nutrients in the biological bag 3 are separated out along with water flow, part of the beneficial microorganisms and nutrients enter a river water body, and part of the beneficial microorganisms and nutrients are attached to the surface of the zeolite structure 34, after metabolism and reproduction activities, a biological film is formed on the surface of the zeolite, and then dominant flora is quickly formed on two sides of the river, so that the degradation of pollutants such as organic matters, ammonia nitrogen, total nitrogen and the like in the water body is accelerated, and the dissolved oxygen content of the water body is improved. The formation of the dominant flora firstly separates out microorganisms by the biological bags 3 to construct in a local small range, and then attracts suitable microorganisms in the original river water in the local range, so that the microorganisms proliferate, the dominant flora range is gradually expanded, and the aims of constructing beneficial flora in the river and rapidly degrading pollutants are finally fulfilled.

Secondly, a concave-convex structure is constructed at the lower part of the gravel structure, so that the turbulence degree of the area where the dominant flora is located is increased, the beneficial components and oxygen on the water surface are transmitted to the bottom of the river water, and nutrients and oxygen are provided for animals and plants in the river water. Meanwhile, substances at the bottom of the river water can be transmitted to the water surface, so that nutrients are provided for the growth of the dominant flora, and a benign substance circulation is formed. In addition, the turbulence in the area where the dominant flora is located is increased, so that the diffusion of the dominant flora from two sides of the river channel to the center of the river channel and even to the whole river is accelerated, the benign substance circulation can be generated in the whole river, the ecological function of the whole river is greatly improved, and the self-purification capacity of the whole river is improved.

Finally, the shallow root grass on the vegetation plate 2 provides stable and good living environment for the dominant flora, and the dominant flora can also provide enough nutrients for the shallow root grass, so that the revetment-river ecosystem is finally realized, and continuous power is provided for improving the ecological function of the whole river and improving the self-purification capacity of the whole river.

In order to better illustrate the beneficial effects in the embodiment of the invention, the invention provides a concrete embodiment of the revetment: the total height of the revetment is 1.2m (without vegetation), 40cm below the water surface and 80cm above the water surface. The average number of the concave-convex structures is 12/10 m, and the average angle is 124.7 degrees. The size of the gravel is 25-40 cm. The zeolite has a specification of 220 meshes and a specific surface area of 300m ² G, density of 2.1g/cm ³ Hydrochloric acid solubility 0.1%, NH ⁴⁺ Exchange capacity 17mg/100 g. In a biological bag within 15cm below the water surface, microorganisms mainly comprise photosynthetic bacteria and bacillus subtilis, and play a role in degrading pollutants such as nitrite and hydrogen sulfide and improving dissolved oxygen in water; the biological bags are 15cm above the water surface, and microorganisms mainly comprise yeast and nitrobacteria and play a role in degrading organic matters, nitrates and other pollutants. The vegetation planting comprises the following steps: eclipta alba, canna indica, calla, acorus gramineus and the like. The total length of the revetment is 1.2km, the water surface width is 12m, the depth is about 70cm, and the water quality before and after river water enters the revetment area is as follows:

	COD(mg/L)	Ammonia nitrogen (mg/L)	Total nitrogen (mg/L)	Dissolved oxygen (mg/L)
					Before entering	44	3.1	3.2	2.2
After entering	27	1.9	1.9	4.1
					Rate of improvement	38.6％	38.7％	40.6％	86.4％

Therefore, the revetment provided by the embodiment of the invention can greatly improve the quality of river water.

As shown in fig. 5, a construction method of an ecological gravel revetment for degrading micro-pollutants in a water body comprises the following steps:

step 501, leveling the surface of the shoreline to obtain a leveled shoreline base.

Step 502, laying a plurality of layers of net cages in gradient distribution on a shore line base, wherein one or more layers of net cages at the bottom form a concave-convex structure.

And 503, placing gravel in each net box to form gravel units.

And 504, respectively arranging biological bags on the outer surfaces of the gravel units according to the river water level.

In an embodiment of the invention, the bio-bag comprises a zeolite structure, beneficial microorganisms and nutrients for the beneficial microorganisms, which are adsorbed in the zeolite structure.

And 505, installing a vegetation plate on the outer surface of the gravel unit outside the biological bag arrangement area.

Specifically, the shoreline ground surface is leveled, weeds are cleared, and the foundation is tamped. The net cages are woven by steel wires and fixed on a shoreline base layer by layer, wherein one or more layers of net cages at the bottom form a concave-convex structure. After each layer of net cage is fixed, a layer of gravel and a biological bag are placed in the net cage, wherein the biological bag selects anaerobic type, facultative type and aerobic type according to the position of the water depth. After the net cage is laid, the uppermost layer is connected with the vegetation board. And (3) paving planting soil on the vegetation board, and planting aquatic plants or terrestrial plants according to the water level.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims (7)

1. The utility model provides an ecological gravel revetment of degradation water micro-pollutant which characterized in that includes: net cages, gravel structures, biological bags and vegetation plates;

the biological bags are arranged on the outer surface of the gravel structure;

the vegetation plate is arranged on the outer surface of the gravel structure outside the biological bag arrangement area; the biological bag comprises a zeolite structure, beneficial microorganisms and nutrients of the beneficial microorganisms, and the beneficial microorganisms and the nutrients of the beneficial microorganisms are adsorbed in the zeolite structure to form a biological film on the surface of the zeolite;

the outer surface of the gravel structure is provided with a concave-convex structure, wherein a plurality of layers of net cages distributed in a gradient manner are paved on a flat shoreline base, and one or more layers of net cages at the bottom form the concave-convex structure; after each layer of net cage is fixed, placing a layer of gravel and a biological bag into the net cage;

the gravel structure comprises a plurality of gravel units; placing gravels in the net boxes to form gravel units, wherein adjacent gravel units are arranged in a staggered mode to form a concave-convex structure on the outer surface of the gravel structure, the gravel units are convex structures, a gap between two adjacent convex structures is a concave structure, and the concave-convex structure is positioned at the lower part of the gravel structure; the vegetation board comprises: carrying plate, planting matrix and vegetation;

The vegetation is planted on the planting substrate;

the carrying plate bears the planting substrate;

the vegetation board is hinged with the top surface of the gravel unit.

2. The gravel revetment of claim 1,

in the concave structure, the included angle between the opposite surfaces of the two gravel units is more than or equal to 120 degrees.

3. The gravel revetment according to claim 2,

the vegetation is planted by shallow root system grass, and the length of the root system is 10-25 cm;

the planting substrate is formed by mixing common garden soil, a drainage material, a light aggregate and humus soil;

4. the gravel revetment according to claim 1, wherein the vegetation board is hinged to the top surface of the gravel unit by a connector link, the connector link is disposed at the bottom end of the vegetation board, and connects the top surface of the gravel unit and the bottom surface of the vegetation board.

5. The gravel revetment according to claim 4,

the top surface of gravel unit is the inclined plane, the vegetation board with the inclined plane butt of gravel unit, the top surface of gravel unit the border with the border passes through on the bottom surface of vegetation board the connector link is articulated, other limits of the bottom surface of vegetation board are the free state, and when the vegetation board immerged in the water, the vegetation board floated.

6. The gravel revetment of claim 1, wherein said bio-bag is one or more of an aerobic bio-bag, a facultative bio-bag, and an anaerobic bio-bag.

7. The construction method of the ecological gravel revetment for degrading the micro-pollutants in the water body is characterized by comprising the following steps of:

(1) leveling the surface of the shoreline to obtain a leveled shoreline base;

(2) laying a plurality of layers of net cages in gradient distribution on the shore line base, wherein one or more layers of net cages at the bottom form a concave-convex structure;

(3) placing gravel in each net cage to form gravel units;

(4) respectively arranging biological bags on the outer surfaces of the gravel units according to the river water level; the biological bag comprises a zeolite structure, beneficial microorganisms and nutrients for the beneficial microorganisms, the beneficial microorganisms and the nutrients for the beneficial microorganisms being adsorbed in the zeolite structure;

(5) and installing a vegetation plate on the outer surface of the gravel unit outside the biological bag arrangement area.

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