CN104787891A - An algae bloom ecological control system based on micro-terrain transformation, an ecological method for controlling algae bloom and its application - Google Patents

Abstract

The invention discloses an algae bloom ecological control system based on micro-terrain transformation, an ecological method and application for controlling algae bloom, and belongs to the technical field of ecological engineering. The algae bloom ecological control system based on micro-terrain transformation of the present invention integrates terrain transformation technology, wetland bank slope protection technology, wetland vegetation planting technology and hydrological communication technology. The ecological control system and ecological method of the present invention can not only effectively suppress the occurrence of algae blooms, but also collect a large number of harmful algae produced after the algae "bloom", and can also intercept the spread of harmful algae to the near shore, eliminating the impact on the water quality of near shore water bodies, Adverse effects on air environment and landscape on the island.

Description

An algae bloom ecological control system based on micro-terrain transformation, an ecological method for controlling algae bloom and its application

technical field

The invention belongs to the technical field of ecological engineering, and relates to an algae bloom ecological control system based on micro-topography transformation, an ecological method and application for controlling algae bloom.

Background technique

In the past 10 years, eutrophication and algae blooms have occurred frequently in wetland water. As the "kidney of the earth", the eutrophication of wetland water, the reduction of biodiversity and the vulnerability of biological chains have always been hot and difficult issues in the field of wetland science. With the development of human society and economy and the improvement of living standards, people's domestic water, industrial and agricultural water use have increased sharply, the eutrophication of wetland water has become increasingly serious, and algae blooms have occurred frequently, such as the Taihu Lake cyanobacteria bloom in 2007 and Chaohu Lake in 2010. Blue-green algae blooms have brought negative impacts on local production and life, seriously interfering with regional water safety. Although various measures are taken to control wetland water eutrophication and slow down the frequency of algae blooms, whether it is source control (such as non-point source pollution control and sediment dredging, etc.) to reduce nutrient load, or adopt various algae removal measures (such as Artificial salvage and algicide injection, etc.) failed to achieve the expected results or were only effective in the short term, and some of them exacerbated the collapse of the fragile wetland ecosystem due to improper physical or chemical methods.

At present, the technical methods for the prevention and control of lake water blooms at home and abroad can be roughly attributed to physical methods, biological methods and chemical methods. Physical methods are costly and uneconomical, and cannot fundamentally eliminate the stimulating effect of nutrients on algae. For example, aeration and oxygenation equipment requires large power and high cost, and is more effective for closed water bodies. Delamination and mixing are only effective in water bodies whose depth is more than twice the water depth in the photic zone; in the case of water shortages, it is not advisable to scour with a large amount of water; algae harvesting equipment is greatly affected by power, range of activities and efficiency. The chemical method is to control the reproduction of algae in water by screening or synthesizing chemical agents, and put one or several synthetic safe chemical products in a safe and reliable dose, so that the purpose of killing algae can be quickly achieved, and can In a certain period of time, it can inhibit the growth of algae. However, chemical methods are likely to cause drug residues, which can also produce secondary pollution and damage the water environment while improving the water environment. Biological methods mainly control algal blooms from an ecological point of view through nutrient competition and grazing relationships among organisms. The biological method emphasizes the management of the entire ecosystem and the control of algae from the nutritional link. At present, microbial control, algae-eating organisms, and aquatic plant suppression are mainly used. The advantage of the biological method is that it is simple. However, the current biological and ecological methods are difficult to effectively inhibit the occurrence of algae blooms.

Contents of the invention

According to the needs and deficiencies of the above fields, the present invention provides an algae bloom ecological control system based on micro-terrain modification, an ecological method and application for controlling algae bloom. The algae bloom ecological control system and ecological method of the present invention can not only effectively suppress the occurrence of algae blooms, but also collect a large amount of harmful algae produced after the algae "bloom", and can also intercept the spread of harmful algae to the near shore, eliminating damage to the near shore. Adverse effects on water quality, island air environment and landscape.

Technical scheme of the present invention is as follows:

An algae bloom ecological control system based on micro-terrain transformation, characterized in that the control system integrates terrain transformation technology, wetland shoreline slope protection technology, wetland vegetation planting technology and hydrological communication technology.

The hydrological communication technology mainly includes four methods: expanding and excavating small water surfaces, communicating small water surfaces, local deep excavation, and regional stagnant water; it aims to adjust the shape, scale, and spatial layout of water bodies, stabilize the water area, and optimize the wetland restoration area. The pattern of water resource allocation re-establishes good horizontal and vertical connections between water bodies.

The terrain transformation mainly includes: constructing shoal wetlands, regularizing small water surfaces, and creating habitat islands; aiming at reducing steep or high landforms, leveling local terrain to meet the needs of birds, creating habitat islands, and regularizing the shape of small water surfaces , improve and create the living environment of wetland vegetation and water birds, and increase the heterogeneity and stability of wetland habitats.

The wetland vegetation planting technology mainly includes: restoring small-scale water surface vegetation, restoring large-scale water surface vegetation, restoring normal water level outcropping vegetation, restoring vegetation below normal water level, restoring waterfront vegetation, restoring isolation zone vegetation, and restoring slope consolidation and coastal areas. Vegetation: It aims to build an optimized wetland vegetation community structure by planting suitable wetland plants, moderately regulate the succession direction of wetland plant communities, create an environment suitable for wetland animals to live, and restore the degraded wetland biological chain.

The wetland bank slope protection technology mainly includes: wooden pile slope protection, block stone slope protection, ecological bag slope protection and ecological concrete brick slope protection; it aims to plant aquatic plants with a relatively developed root system on the side of the water by configuring natural fixing materials to fix the soil and strengthen the bank. It has the ability to resist water impact and subsidence to ensure the stability of the bank and the rapid recovery of vegetation; the wooden piles include some living wooden piles; the natural fixing materials are natural stones, wooden piles, and ecological bricks.

Application of the above-mentioned algae bloom ecological control system.

An ecological method for controlling algae blooms is characterized in that the method integrates terrain modification technology, wetland bank slope protection technology, wetland vegetation planting technology and hydrological communication technology.

The method first uses an excavator to dig out and accumulate the bottom mud of the river body to form multiple cofferdams, and then plant different aquatic plants in different cofferdams; extending from the junction of the cofferdam bank and the water body to the water body for 5-15m Emergent plants are planted when the water depth is 0-30cm; submerged plants are planted from the boundary of the emergent plant area to the middle of the water body where the water depth does not exceed 2m; hygrophytes or wet-loving plants are planted on the cofferdam.

The invention utilizes the action of water flow to collect a large amount of harmful algae produced after the algae "bloom", and conducts harmless treatment through artificial measures; Adverse effects on air environment and landscape.

Water system transformation (hydrological connectivity technology): Hydrological connectivity technology is mainly used in degraded wetlands where hydrological conditions have been destroyed. Hydrological communication technology is to adjust the shape, scale and spatial layout of water bodies through engineering measures, stabilize the water area, optimize the distribution pattern of water resources in the wetland restoration area, and re-establish good horizontal and vertical connections between water bodies (that is, to make each interconnected water bodies), improve the ecological environment of the wetland, ensure the normal input and output of nutrients in the wetland ecosystem, and regulate the water conditions of the wetland biome. Hydrological communication technology mainly includes four methods: expanding and excavating small water surface, communicating small water surface, local deep excavation and regional stagnant water.

Expanding and excavating small water surface technology: By excavating the shore with too small water surface, the infiltration area of the water surface is expanded and the flooded area is increased.

Communication small water surface technology: By connecting adjacent too small water surfaces, a stepped series bubble system is constructed to enhance natural infiltration between water bodies, establish horizontal hydrological communication, and increase water stability.

Local deep excavation technology: through local deep excavation in shallow water areas, the vertical hydrological connection with the aquifer layer will be enhanced, and the local water volume of the wetland will be increased.

Regional stagnant water technology: build small stagnant water and water retention facilities in the downstream area of the region to control water loss and increase the stability of regional water body area and water volume.

Terrain transformation technology: Terrain transformation technology is mainly used to transform the topography of degraded wetlands and create a suitable environment for the survival of wetland organisms. Through engineering measures, reduce the landform that is too steep or too high, level the local terrain (suitable for birds, etc.), create habitat islands, and regularize the shape of small water surfaces, so as to improve and create the living environment of wetland vegetation and water birds, and increase the diversity of wetland habitats. quality and stability. Terrain transformation mainly includes: building shoal wetlands, regularizing small water surfaces and creating habitat islands.

Shoal wetland construction technology: Local land leveling is carried out on the open area near the undulating water surface, and the overly high terrain is leveled to create an open environment suitable for the growth of wetland vegetation and the habitat of water birds.

Small water surface regularization technology: By regularizing the shape of small water surfaces, the stability of wetlands is increased.

Habitat island construction technology: According to the habitat requirements of different types of waterfowl, an island suitable for waterfowl habitat is built on the open water at a certain distance from the shore.

Substrate construction technology: This technology provides an excellent habitat for wetland plants and biological chain restoration, that is, the constructed substrate can promote the growth and reproduction of organisms, and mainly involves the restoration of degraded wetlands with poor soil or lack of loamy soil. Backfill loamy soil in nutrient-poor areas through engineering measures, enhance the ability of wetland substrates to store water and nutrients, improve the transfer of nutrients in wetland ecosystems, provide breeding grounds for soil organisms, and provide good nutritional conditions for vegetation. Animals such as birds provide habitat. Substrate construction techniques mainly include: layered backfilling loamy soil, planting pit backfilling loamy soil and planting groove backfilling loamy soil.

Layered backfill technology: In the open area with poor soil, layered backfill the soil that meets the growth requirements of wetland vegetation to restore the wetland matrix.

Planting pit backfill technology: within the restoration area, planting pits of different specifications are excavated and backfilled with loam.

Planting tank backfilling technology: In the coastal zone with poor soil, excavate planting tanks and backfill with loam.

Wetland vegetation planting technology: mainly the optimal allocation of wetland plants and its application to degraded wetlands with low vegetation coverage or no vegetation coverage. By planting suitable wetland plants, construct an optimized wetland vegetation community structure, moderately regulate the succession direction of wetland plant communities, create an environment suitable for the survival of wetland animals, and restore the degraded wetland biological chain. Wetland vegetation planting techniques mainly include: restoration of small-scale water surface vegetation, restoration of large-scale water surface vegetation, restoration of vegetation on the open beach at normal water level, restoration of vegetation below normal water level, restoration of vegetation in the waterfront zone, restoration of vegetation in the isolation zone, and restoration of vegetation in the slope consolidation zone.

Small water surface vegetation restoration technology: mainly natural restoration.

Large-scale water surface vegetation restoration technology: mainly spread the propagules of submerged and floating plants in an appropriate amount, such as foxtail algae, squid, and water lily.

Vegetation restoration technology on open beach at constant water level: mainly plant seedlings of low hygrophytes.

Vegetation restoration technology below normal water level: mainly plant seedlings or propagules of tall emergent plants.

Waterfront vegetation restoration technology: mainly plant propagules or seedlings of wet shrubs.

Vegetation restoration technology in the isolation zone: mainly plant tall trees and shrubs.

Slope consolidation and shore zone vegetation restoration technology: mainly planting shrubs with well-developed root systems.

Wetland bank slope protection technology: mainly used in areas that are vulnerable to water impact and subsidence. By configuring natural stones, wooden piles (some living wooden piles), ecological bricks and other natural fixing materials, aquatic plants with developed root systems that can fix the soil are planted on the water side to enhance the shore zone's ability to resist water impact and subsidence, and ensure the stability of the slope bank and rapid recovery of vegetation. Coastal slope protection technologies mainly include: pile slope protection, block stone slope protection, ecological bag slope protection and ecological concrete brick slope protection.

Wood pile slope protection technology: wood pile slope protection uses willow piles to drive into steeper slopes vertically and vertically to the horizontal plane. Part of the piles can survive to form hedges and enhance the effect of slope protection. The slope is covered with shallow soil, and planted perennial herbs and small shrubs with well-developed root systems.

Block stone slope protection technology: block stone slope protection technology is mainly to pave the lower layer of the slope that needs to be stabilized near the water's edge with gravel, and lay two circles and two layers of 30-50cm block stones on it, and use the gravity of the block stone to lay Loam soil is fixed to prevent water impact and erosion, the slope is covered with shallow soil, and slope protection plants mainly planted with Amorpha fragrans, seabuckthorn and willow willow are planted to fix the slope.

Ecological bag slope protection technology: mainly used in coastal areas that are easily eroded by water flow. Ecological bags filled with filled substrates are stacked in layers according to the direction of the bank slope. The ecological bags are connected with the ecological bags by locks, and the ecological bags can be filled Sand, loam and other substrates, and cross-shaped openings of different specifications can be cut on the ecological bag, and wetland plant seeds or wetland plant larvae can be spread.

Ecological concrete brick slope protection technology: mainly used in coastal areas that are easily eroded by water waves and easily collapsed. Ecological bricks are used to stack and use their gravity to fix the shore zone to prevent further erosion of water flow. Wetland plants with well-developed roots can also be planted , to create a wetland habitat and increase the wetland landscape effect.

Beneficial effects of the algae bloom ecological control system based on micro-topography modification of the present invention:

The present invention can use the action of water flow to collect a large amount of harmful algae produced after the algae "bloom", and carry out harmless treatment through artificial measures; the project can also intercept harmful algae from spreading to the shore, eliminating the impact on the water quality of near-shore water bodies and the air on the island. Adverse impacts on the environment and landscape.

Description of drawings

Fig. 1 is the schematic diagram of slope protection of single row of wooden piles;

Fig. 2 is a schematic diagram of slope protection with double rows of wooden piles;

Fig. 3 is the schematic diagram of vegetation slope protection;

Fig. 4 is a schematic diagram of gravel block slope protection;

Fig. 5 is the ecological zone slope protection schematic diagram;

Fig. 6 is the schematic diagram of ecological concrete slope protection;

Fig. 7 is engineering layout drawing of the present invention;

Fig. 8 is the SD change trend figure of the water body after the treatment of embodiment 1;

Fig. 9 is the pH variation trend figure of the water body after the treatment of Example 1;

Fig. 10 is the TN change trend figure of the water body after the treatment of embodiment 1;

Fig. 11 is the TP variation trend figure of the water body after the treatment of embodiment 1;

Fig. 12 is the change trend figure of CODMn of the water body after the treatment of embodiment 1;

Fig. 13 is the Chla variation trend figure of the water body after the treatment of embodiment 1;

Fig. 14 is a graph showing the changes in the amount of algae eliminated during cyanobacteria outbreaks in the water body treated in Example 1 in 2013.

detailed description

The following examples are provided in order to further understand the present invention better, are not limited to the best implementation mode, and do not limit the content and protection scope of the present invention, anyone under the inspiration of the present invention or use the present invention Any product identical or similar to the present invention obtained by combining features of other prior art falls within the protection scope of the present invention.

Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. The materials used in the present invention, unless otherwise specified, are commercially obtained, or prepared by conventional experimental methods; the test methods used in the examples, unless otherwise specified, are conventional experimental methods well known to those skilled in the art.

Example 1.

(1) Treat eutrophic water bodies

On November 20, 2009, the algae bloom ecological control system based on micro-topography modification of the present invention was used to treat the eutrophic Taihu Lake water body.

Control engineering design basically includes: algae "algae bloom" comprehensive control system integrates and applies various technologies such as terrain transformation, wetland ecological revetment, wetland plant optimization configuration, biological chain restoration, and hydraulic connectivity. The specific projects include waterfront design, water system transformation, Animal and plant restoration, etc. The project is divided into six processing units, which use the movement of water to collect a large number of harmful algae produced after the "algae bloom" and carry out harmless treatment through artificial measures; the project can also intercept the spread of harmful algae to the shore of Sanshan Island, eliminating the harmful Adverse effects on the water quality of nearshore water bodies, the air environment on the island and the landscape.

In Example 1, the bottom mud of Taihu Lake was excavated and accumulated by an excavator to form multiple cofferdams, and then different aquatic plants were planted in different cofferdams. Among them, the main plant communities in areas ① and ② (Figure 7) in the project area are emergent plants such as artificially planted reeds and wild rice plants, which extend from the junction of the bank zone of the cofferdam and the water body to a distance of 5-15m in the water body. The water depth here is about 0-30cm. This area can purify the pollutants brought by the rainwater runoff on the shore, and at the same time, it can play a role in beautifying the environment. Areas ③ and ④ (Figure 7) start from the boundary of the emergent plant area to the place where the water depth does not exceed 2m in the middle of the water body. At the same time, it plays the role of enriching algae in the surrounding water body. Plant hygroscopic or wet-loving plants on the cofferdam. Areas ⑤ and ⑥ (Fig. 7) are located outside the cofferdam, far away from the lake shore, and are undisturbed waters of Taihu Lake, in which submerged plants are rare, and there are a small amount of floating leaf plants such as waterweed near the cofferdam. It can also purify the pollutants in the water body, and at the same time, it can enrich the algae in the peripheral water body to ⑤ and ⑥. ⑧The area is the periphery of the project area and belongs to the project control area.

(2) Effect verification

From January 2010 to December 2013, a total of 21 sampling points were set up in 6 treatment units and control areas. At the same time, the water quality was tracked and monitored on a monthly basis. Surface water samples were collected at each station (depth less than 0.5m ), the specific data are as follows:

Transparency (SD) change law:

It can be seen from Figure 8 that from January 2010 to December 2013, with the change of seasons, the water transparency (SD) of unit 1 varied from 0.57 to 1.24 cm, but the overall transparency showed an upward trend. From January 2012 to December 2013, the transparency of the water body during June to October was significantly higher than that in other months; Unit 2 and the control also had the same law, but the change law of Unit 3 was not obvious, and the water transparency in each month was basically the same. The comparative analysis shows that since January 2010, the water transparency of unit 1 is significantly higher than that of other units and the control area (p<0.01).

pH time change rule:

Figure 9 shows that the pH value of unit 1 varies between 6.90 and 8.10, and increases with time. The pH of each unit from April to October in 2012 was significantly higher than that in other months. The pH of unit 1 was significantly different from other units (p<0.01), but the difference between unit 2, unit 3 and the control was not significant (p>0.05). Monitoring shows that although the water temperature changes with the seasons, when the blooms and algae are well controlled in the enclosure, the productivity of the ecosystem dominated by submerged plants is higher, and the amount of carbon dioxide fixed in the water body increases accordingly, resulting in a decrease in the pH of the water body. Relatively higher outside the enclosure.

Variation rules of nutrient elements:

Figures 10 and 11 show that before the ecological restoration, the concentration of TN in the water body inside and outside the enclosure belongs to the standard limit value of Class V surface water quality; L decreased to 0.55mg/L, and the total nitrogen content in the control area did not change much from 0.78mg/L to 1.62mg/L. Since January 2009, the inside of the enclosure was significantly lower than that outside the enclosure (p<0.01); until December 2013, the total nitrogen concentration in unit 1 water decreased by 68.0% compared with that outside the enclosure. During the establishment of submerged plants, the total phosphorus concentration in the water body in the project area also showed a downward trend. The total phosphorus concentrations of the water inside the enclosure and the water outside the enclosure were 0.06 and 0.05mg/L at the initial stage, both of which were in the Class II surface water quality standard. Comparative analysis showed that the total phosphorus concentration in the enclosure was significantly lower than that outside the enclosure from January to September 2013 (p<0.01). As of December 2013, the total phosphorus concentration outside the enclosure was 0.04mg/L, and the total phosphorus concentration inside the enclosure was 0.02mg/L, a decrease of 50.0%.

COD change law:

Figure 12 shows that at the initial stage of the mesosome establishment, the concentrations of CODMn in the water inside and outside the mesosome were 12.6 and 12.7 mg/L, respectively, which were at the same level. From March to September 2013, the CODMn content in the enclosure was significantly lower than that in the control area (p<0.01), especially in unit 1, through the self-purification of large cladocera and submerged plants in the water body. lower than the control area. By December 2013, the content of COD _Mn in the water outside the enclosure had no difference from the initial stage (p>0.05), which was 4.8mg/L, while the COD _Mn content in the water inside the enclosure dropped to 4.4mg/L. A year-on-year decrease of 70.9%.

Chla Variation and Algae Treatment:

Figure 13 shows that there is still a peak in the Chla content of unit 1 in 2009 and 2010 from June to September every year, but the change after 2011 is not obvious. The Chla content of Unit 1, Unit 2, Unit 3 and the control area was significantly different (p<0.01), and the Chla content of Unit 2, Unit 3 and the control area was also significantly different (p<0.01).

Figure 14 shows that 0.2-0.3t of algae weight (wet weight) can be processed per day from April to June; about 1 ton of algae weight (wet weight) can be processed per day from July to September; about 0.5t of algae can be processed per day in October Weight (wet weight), the increase in processing capacity from July to September fully shows that the occurrence of algae blooms is serious in this month.

Preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without any creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited number of experiments on the basis of the prior art shall be within the scope of protection defined in the claims of the present invention. within.

Claims (8)

1. based on an algal bloom Ecological Control system for micro-slope reconstruction, it is characterized in that, described control system integration have employed topography reform technology, wetland bank band bulkhead tech, muskeg planting technology and hydrology UNICOM technology.

2. algal bloom Ecological Control system according to claim 1, is characterized in that, described hydrology UNICOM technology mainly comprises: dig small face, link up small face, local is deep-cut and region backwater four kinds of methods; Be intended to adjust water shape, scale, space layout, stablize water surface area, optimize water resource assignment general layout in wetland recovery region, re-established horizontal connection good between water body and vertical linkage.

3. algal bloom Ecological Control system according to claim 2, it is characterized in that, described topography reform mainly comprises: construction shoal wetland, regular small-size water surface and construction habitat island; Be intended to cut the steep or too high landforms of low mistake, smooth local landform with the needs of applicable birds, the shape of building habitat island, regular small-size water surface, improve and build the living environment of muskeg and aquatic bird, increase heterogeneity and the stability in wetland habitat.

4. algal bloom Ecological Control system according to claim 3, it is characterized in that, described muskeg planting technology mainly comprises: recover small-size water surface vegetation, recover large-scale water surface vegetation, recover ordinary water level exposure beach vegetation, recover below ordinary water level vegetation, recover waterfront band vegetation, recover isolation strip vegetation and recover Gu Po and bank zone vegetation; Being intended to by planting suitable wetland plant, building the muskeg structure of community optimized, appropriateness regulation and control Wetland Communities succession direction, builds the environment of suitable wetland animal survival, repairs the wetland ecotourism chain of degenerating.

5. algal bloom Ecological Control system according to claim 4, is characterized in that, described wetland bank band bulkhead tech mainly comprises: timber bank protection, pitched work, ecology bag bank protection and ecological concrete brick bank protection; Being intended to by configuring the natural immobilization material side plantation root system that borders on the river more flourishing in the waterplant of set soil, strengthening bank band anti-current-rush and resist collapse ability, ensure the fast quick-recovery of the firm and vegetation of sloping bank; Described timber comprises part timber alive; Described natural immobilization material is blocks of natural stone, timber, ecological brick.

6. the arbitrary described algal bloom Ecological Control systematic difference of claim 1-5.

7. control an ecological method for algal bloom, it is characterized in that, described method integration have employed topography reform technology, wetland bank band bulkhead tech, muskeg planting technology and hydrology UNICOM technology.

8. method according to claim 7, is characterized in that, first described method utilizes excavator the bed mud of river body to be dug out accumulation and form multiple cofferdam, then in different cofferdam, plants different waterplant; Extend to 5-15m distance in water body from cofferdam bank band and water body junction, the depth of water plants emergent when 0 ~ 30cm; To the place kind planting submerged plant of the not super 2m of the middle depth of water of water body from border, emergent district; Cofferdam is planted humidogene or moisture loving plant.