CN103669282A - Method for disposing river or lake bottom mud on site - Google Patents

Abstract

The invention relates to an ecological engineering technology for in-situ treatment of river (lake) bottom mud and construction of ecological revetment. It is an ecological bag filled with river (lake) sediment and granular components in urban areas, used to build ecological dikes on the banks of cement hardened rivers and lakes, and filled with sediment and other components between the ecological bag and the original shore zone. Mixture, and then plant high-purifying plants such as shrubs and sedges to build an in-situ sediment treatment system. The invention realizes in-situ treatment of river and lake bottom mud polluted by cities, reduces transportation costs, reduces environmental impact, and realizes ecologically harmless treatment and recycling of bottom mud by using a constructed bottom mud matrix, plant and microbial composite system. The formed near-natural plant ecological zone can intercept and absorb non-point source pollutants brought into rivers (lakes) by surface runoff and reduce pollution levels.

Description

A method for in-situ treatment of river and lake sediment

 

technical field

The invention belongs to the technical field of environmental protection, and in particular relates to a method for treating river and lake bottom mud on site.

Background technique

With the rapid development of the economy and the continuous expansion of the city scale, the pollution of rivers and lakes is becoming more and more serious. Due to farmland reclamation and vegetation destruction in the watershed, soil erosion has intensified. In order to maintain the clear water landscape, the city builds dams and other facilities, which accelerates the accumulation of sediment in rivers and lakes, and affects ecological security issues such as urban water storage and flood control. Therefore, the disposal of sediments with a large amount of pollutants accumulated in rivers and lakes in urban areas has become an urgent problem for the current government and society. A large amount of organic debris, toxic and refractory substances, heavy metals, etc. are deposited in the bottom mud of rivers and lakes, resulting in aggravated bottom mud pollution. When the point source pollution and non-point source pollution are relatively large, the sediment can enrich these pollutants; and when the point source pollution and non-point source pollution are controlled, the pollutants deposited in the bottom mud can be physically and chemically Under the action of organic matter and organisms, complex changes occur in the sediment, and then pollutants are released into the water body, posing a threat or even damage to the aquatic ecosystem, and thus threatening human health.

For the treatment of polluted river and lake sediments, centralized treatment after dredging is mostly used at present. The pollutants on the surface of lake sediments are excavated by hydraulic or mechanical methods, and then transported to reduce the release of sediment pollutants. Although dredging can effectively solve the pollution situation of rivers, since the dredged sediment still needs to be followed up, excavating corresponding waste pits for landfill, transportation and excavation costs also increase the cost of sediment dredging; and A large number of pollutants contained in the sediment will also enter the soil to cause secondary pollution and form new environmental problems. There are also many descriptions of river and lake sediment treatment methods in existing patents, such as a method of using modified zeolite to control the release of phosphorus from sediment in situ (CN103408209A), an integrated test device for river and lake dredging and sludge dehydration and drying And method (CN103408207A), multi-stage water quality ecological purification system suitable for shallow and narrow mixed water channels (CN103351084A), treatment system and treatment process for removing polluted sediment from rivers in central urban areas (CN103334469A), contaminated sediment treatment device (CN203307188U) However, most of them are limited to changing the physical and chemical properties of the sediment through physical and chemical methods, ignoring the combined effect of biology and ecology, and all need to be treated in different places, which invisibly increases the cost of transportation.

With the rapid development of my country's economy, the continuous expansion of the city scale, the increasing water pollution of rivers and lakes, the treatment of polluted sediment has also become a hot issue, how to deal with the sediment at low cost, harmless and resourceful will be The focus of government and society's attention.

Invention content

The present invention aims at the above deficiencies in the bottom mud dredging post-treatment technology, and according to the particularity of river and lake ecosystems, proposes a method for treating river and lake bottom mud in situ.

The technical scheme adopted in the present invention:

The river (lake) sediment is dredged and transported to the bank of the river and lake, and mixed evenly with the coarse and fine material components in a certain proportion to form a mixed matrix of sediment, and the mixed matrix of sediment is filled to a corrosion-resistant, permanent non-degradable, and In the ecological bag with good water permeability, the ecological bag is piled up at a distance of 1-2 meters from the bank of the river (lake), and anchored by anchor piles to form an ecological embankment. The ecological embankment is about 50-80cm above the water surface. Fill the bottom mud mixed matrix between the embankment and the original river (lake) bank, and plant plants on the bottom mud mixed matrix that can efficiently remove pollutants and have the function of beautifying the environment. The plants can be shrub plants and herbaceous plants. Realize the interception of non-point source pollution carried by surface runoff in the opposite shore zone, and the removal of pollutants in sediment and water bodies. At the same time, it has multiple functions such as landscaping and ecological revetment, and realizes the goal of low-cost, harmless and resource-based treatment of sediment .

Bottom mud and coarse and fine material components make up the bottom mud mixed matrix by weight ratio:

Coarse material component 20%-40%

Fine material composition 20%-40%

Sediment Components 40%

The sum of each component is 100%;

The coarse material component is one or more of steel slag, volcanic slag, furnace ash and gravel, which can be mixed in any proportion;

The fine material component is one or more of perlite, zeolite, vermiculite and volcanic ash, which can be mixed in any proportion;

The diameter of the fine material component is less than 5 mm, and the diameter of the coarse material component is greater than 10 mm;

The plants that can efficiently remove pollutants and have the function of beautifying the environment planted on the mixed substrate can be shrub willow and sedge, and the planting density of both is: 1 shrub willow/m ² and 5 sedge/m ² ,

Compared with the prior art, the present invention has the following advantages:

1. The present invention realizes low-cost and harmless treatment of urban river and lake sediment after dredging, reduces transportation costs, and reduces impact on other environments. Through the in-situ treatment system constructed by using the sediment and other components, the growing plants and microorganisms can improve the physical and chemical properties of the sediment, and through the synergistic effect of physics, chemistry and biology, it can reduce and remove the sediment in the sediment. Pollutants, to a certain extent, to achieve the restoration of the structural components of the sediment, to achieve the goal of harmlessness;

2. The in-situ treatment system built for river and lake sediments not only repairs the sediment, but also improves the river water quality to a certain extent, and at the same time has a certain degree of interception effect on the runoff pollution flowing into rivers and lakes;

3. The near-natural revetment on-site treatment system constructed by using river and lake bottom mud can also realize functions such as ecological revetment, urban leisure and entertainment area landscape beautification, etc. At the same time, it has a good environmental publicity and education function, which helps to improve residents' environmental protection awareness and environmental protection. Knowledge.

Description of drawings

The accompanying drawing is a schematic diagram of an in-situ treatment method for river and lake sediment

In the figure: 1. Ecological embankment, 2. Plants, 3. Sediment mixed matrix, 4. Anchorage piles.

Detailed ways

Example 1:

In an artificial lake with a water depth of 1m, take the mixed substrate of sediment and put it into an ecological bag, and pile up the ecological bag at a distance of 2 meters from the lake shore to form an ecological embankment. The embankment surface is 50cm above the water surface and anchored. The bottom mud mixed matrix is uniformly mixed with bottom mud, coarse material component slag, and fine material component vermiculite at a weight ratio of 40%: 40%: 20%, and then the bottom mud mixed matrix is filled in the original lakeshore and ecological embankment Between, and then plant 1 shrub willow and 5 carex per square meter.

Example 2:

On the river bank with a water body depth of 2 m, the bottom mud is uniformly mixed with the coarse material components slag and gravel, and the fine component perlite at a weight ratio of 40%:20%:40% to form a bottom mud mixed matrix, and the bottom mud is mixed The matrix is put into the ecological bag, and the ecological bag is piled up 1 meter away from the river bank to form an ecological embankment, which is anchored, and the embankment surface is 60cm above the water surface. Then fill the bottom mud mixed matrix between the original river bank and the ecological embankment, and then plant 1 shrub willow and 5 carex per square meter.

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Example 3:

On a river bank with a water depth of 3 m, the bottom mud, coarse material components, steel slag and gravel, and fine material components, perlite and volcanic ash, were uniformly mixed at a weight ratio of 40%:30%:30% to form a bottom mud mixed matrix. The bottom mud mixed matrix is put into an ecological bag, and the ecological bag is piled up 1.5 meters away from the river bank to form an ecological embankment, which is anchored, and the embankment surface is 70cm above the water surface. Then fill the bottom mud mixed matrix between the original river bank and the ecological embankment, and then plant 1 shrub willow and 5 carex per square meter.

Example 4:

On the shore of the lake with a water depth of 3m, the bottom mud, the coarse component slag and volcanic cinder, and the fine component zeolite are uniformly mixed at a ratio of 40%:25%:35% to form a bottom mud mixed matrix, and the bottom mud mixed matrix is loaded into the Ecological bags, stacking ecological bags 1 meter away from the lake shore to form an ecological embankment, and anchored, the embankment surface is 80cm above the water surface. Then fill the bottom mud mixed matrix between the original lake bank and the ecological embankment, and then plant 1 shrub willow and 5 sedges per square meter.

Claims (2)

1. A method for treating bottom mud of rivers and lakes on the spot is characterized in that river or lake bottom mud is dredged and transported to the bank of river or lake, and is uniformly mixed with thick and fine material components in a certain weight ratio to form bottom mud mixed matrix, Fill the bottom mud mixed matrix into a corrosion-resistant, permanently non-degradable, and good water-permeable ecological bag, stack the ecological bag at a distance of 1-2 meters from the river or lake bank, and use anchor piles to anchor it to form an ecological embankment. The surface of the ecological embankment is about 50-80cm above the water surface. Fill the sediment mixed substrate between the ecological embankment and the original river or lake shore, and plant plants on the sediment mixed substrate that can efficiently remove pollutants and have the function of beautifying the environment. The plants are shrubs. bushes and herbaceous plants, Bottom mud and coarse and fine material components make up the bottom mud mixed matrix by weight ratio: Coarse material component 20%-40% Fine material composition 20%-40% Sediment component 40% The sum of each component is 100%; The coarse material component is one or more of steel slag, volcanic slag, furnace ash and gravel, mixed in any weight ratio; The fine material components are one or more of perlite, zeolite, vermiculite and volcanic ash, which can be mixed in any weight ratio; The diameter of the fine material component is less than 5 mm, and the diameter of the coarse material component is greater than 10 mm. 2. The method for treating the bottom mud of a kind of river and lake according to claim 1 is characterized in that said shrub plants and herbaceous plants are shrub willow and sedge, and the planting density of the two is: 1 shrub willow /m ² , 5 Carex/m ² .

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