With the acceleration of the urbanization process, the amount of urban domestic waste is increasing, and there are more and more landfills.
In all countries, municipal solid waste is construction waste, garden waste, etc., and municipal solid waste comes from various types of construction waste generated by residents’ daily waste, municipal engineering, etc., and kitchen waste generated by sanitation operations.
The waste generated in the city will cause much harm if it is not treated.
All kinds of garbage are toxic and pollute the soil, water, and air, and organic waste such as degradable plastic bags is very harmful to soil and water. At the same time, the leakage of waste garbage will have a serious impact on the water environment: it can lead to eutrophication of the water body and destroy the living environment of aquatic organisms; at the same time, it will also pollute the soil, destroy the soil structure and reduce soil fertility.
Plastic waste also contains a large amount of polycyclic aromatic hydrocarbons, which are also common carcinogens.
Thus, we must deal with garbage in our lives, try to cut the impact of garbage on the environment, and form sustainable development.
Over the past few decades, landfills have been a good way to dispose of trash and all types of waste, producing less soil and water pollution than burning waste. The landfill is an important place for waste collection, treatment, and use.
With the gradual maturity of technology, geotechnical materials have been used in the protection system of landfill. There are many geosynthetic materials used in landfills. This article focuses on several used geosynthetic materials, their mechanism of action, and their advantages and disadvantages.
Application of PE geomembrane in landfill
PE geomembrane is a kind of geosynthetic material, which is used in water conservancy, transportation, construction sites, environmental protection, landscaping, and other fields.
PE geomembrane is an excellent building material with good acid and alkali resistance, corrosion resistance, and frost resistance.
The application of PE geomembrane in landfill has the following advantages:
1. PE geomembrane has good anti-seepage performance, preventing water from entering the soil after landfill;
2. The plastic geomembrane has good tensile strength and compressive strength, and can resist various mechanical equipment and external forces in the landfill;
3. The plastic geomembrane has high tensile strength, bending resistance, high shear strength, high tensile strength, and good waterproof and isolation functions.
4. The plastic geomembrane has strong corrosion resistance, which can prevent the chemical components in domestic waste from corroding the plastic film and causing leakage.
5. The plastic geomembrane has good anti-seepage performance and does not produce any repelling effect on rainwater; it is a waterproof material that can prevent rainwater from penetrating into landfills and soils, ensuring long-term stable operation of landfills; at the same time, it can resist various The harm of various chemical substances (acid, alkali, salt, etc.) to the corrosion of plastic soil machine cloth.
6. Plastic geomembrane has good isolation function.
7. The geomembrane has good waterproof performance, which can prevent rainwater from polluting and destroying the landfill and soil; at the same time, it can prevent various chemical substances in the landfill from damaging the tensile strength of the plastic film.
8. The geomembrane has good corrosion resistance and high anti-aging performance; it can still remain stable after long-term use.
Plastic geomembrane long life: its service life is generally about 20 years or longer.
Due to the good properties of geomembrane, aging resistance, cold resistance, and corrosion resistance, it is used in various construction sites and municipal projects.
PE geomembrane is made of plastic composite, with high strength and high toughness, because of the following advantages it can be used in landfills:
(1) Tensile strength: the tensile strength of plastic geomembrane is ≥110 KN/m. Under normal conditions, its tensile strength is 4-5 times greater than that of non-woven geomembranes.
(2) Anti-seepage performance: Through the tensile test of plastic geomembrane, it can be seen that its tensile, flexural, and puncture resistance is better than non-woven geomembrane
(3) Corrosion resistance: Due to the good permeability resistance of plastic geotextiles, their acid, and alkali corrosion resistance is higher than that of ordinary non-woven fabrics. Thus, the infiltration of moisture in the soil of the landfill can be avoided, protecting the environment and protecting the soil.
(4) Drainage: because the landfill is closed. Rainwater cannot seep in, so there is no seepage in the landfill. When it rains, the rainwater enters the landfill through the gutters
(5) Convenient construction: The geomembrane can be laid.
(6) Good engineering quality: the geomembrane has good toughness and tensile strength, and will not crack during use; at the same time, it can resist various harsh conditions: severe cold, scorching heat, drought, flood, etc. can be well adapted;
(7) Cheap and practical: geomembrane can save engineering costs.
Application of Geotextile Fabric in landfill
Geotextiles, also known as non-woven geotextiles, are made of polypropylene, polyester, etc. through a special process.
Geotextiles have good chemical corrosion resistance, anti-ultraviolet radiation and anti-aging properties, excellent durability and water resistance, and have the characteristics of high strength, longevity, economy, and environmental protection.
This product can prevent problems such as leakage, water seepage, soil erosion, and roadbed settlement, and can be used in the construction of roads, railways, airport runways, water conservancy facilities, and other projects.
Applications of geotextiles include preventing soil and groundwater pollution, protecting environmental quality, and preventing the ingress of harmful substances such as polluting soil, water, and groundwater. Geotextiles can protect the subgrade soil from damage and form effective drainage channels on the subgrade.
Geotextiles are generally permeable materials, so it has a filtering function and can release water from pollutants and drain to prevent pollution.
Depending on the nature and amount of contaminants in the soil, geotextiles can provide materials that maximize their filtering capabilities.
When used in road construction, landfill, and other engineering applications, geotextiles have the following functions:
1. When used in landfill, geotextiles can isolate soil and waste to prevent leakage.
2. The barrier function of the geotextile prevents the landfill from leaking.
3. Geotextile is a filter material that keeps water clean as it passes through pipes and connects pipes.
4. Geotextiles are used to prevent pollutants from landfills from leaking into the soil.
5. If the salinity in the soil is too high, the geotextile can play the role of auxiliary filtration and anti-seepage.
6. If the landfill is unstable, the thickness of the geotextile must be increased to exert its filtering function.
7. If the landfill leachate does not contain heavy metals, such as lead and cadmium, and the leachate is neutral or acidic, geotextiles can be added to avoid soil erosion caused by acid corrosion; soil loss; heavy metal pollution, etc.
All in all, when geotextiles are applied to landfills, they can be used as a buffer layer material; to protect the soil; prevent the spread of waste; keep the soil out: keep the landfill clean; prevent foreign pollutants from entering the site. Because of these properties, geotextiles are an essential filter and protection material in landfills.
Application of Geosynthetics Clay Liner in landfill
Geosynthetics Clay Liner is a composite building material whose main components include bentonite and geotextile.
The Geosynthetics Clay Liner has a three-layer structure, and the upper and lower layers are geotextiles, which play the role of protection and reinforcement. The middle part is a sodium-based or calcium-based bentonite granular layer, which is processed from natural clay ore inorganic materials and has high expansibility and high water absorption capacity. Usually, most geosynthetic clay liners use a calcium-based bentonite granular layer, of which the expansibility and water absorption capacity are better.
Geosynthetics Clay Liner has good water permeability, good air permeability and impermeability, and strong damage resistance. Geosynthetics Clay Liner can be used to prevent groundwater from entering the landfill and prevent land subsidence caused by leakage. It is used in landfills.
Usually, 1~2 layers of Geosynthetics Clay Liners are laid on the bottom of the landfill to provide many anti-seepage guarantees.
Application of Other Geosynthetics Products in landfill
Including composite drainage network, geogrid, geocell, etc.
A three-dimensional composite drainage net is a new type of drainage geotechnical material. It is made of high-density polyethylene (HDPE) through a special extrusion molding process and has a special three-layer structure. The ribs in the middle are rigid and arranged to form a drainage channel. The ribs are arranged vertically and crossed to form a support to prevent the geotextile from being embedded in the drainage channel. Even under high loads, it can maintain high drainage performance. The double-sided bonding water-permeable geotextile is used in combination, has the comprehensive performance of “reverse filtration-drainage-breathing-protection”, and is currently the most ideal drainage material. It is used in drainage projects such as railways, highways, tunnels, landfills, solid waste treatment stations, municipal engineering, reservoirs, and slope protection.
The grid is a two-dimensional grid or a three-dimensional grid screen with a certain height made of polypropylene, polyvinyl chloride, fiber, and other polymers through thermoplastic, weaving, or molding. When used as a civil engineer, called geogrid.
The Characteristics of Geogrids in Projects
1. Various dams and embankment reinforcement, slope protection, and cave wall reinforcement. Reinforcement of permanent load-carrying foundations in large airports, parking lots, wharf yards, etc.
2. Increase the bearing capacity of the road (ground) foundation and prolong the service life of the road (ground) foundation.
3. Prevent the road (ground) surface from subsidence or cracks, and keep the ground beautiful and tidy.
4. It can effectively block the transmission of seismic force, and plays an important role in enhancing the seismic stiffness, strength, and stability of embankments
5. The construction is convenient, saves time and effort, shortens the construction period, and reduces maintenance costs.
6. Reduce the thickness of the cushion and save the cost.
7. Support the stable green environment of slope grass planting mats.
Geocell is a three-dimensional mesh cell structure formed by reinforced HDPE sheet material through high-strength welding. Generally, it is made by ultrasonic needle welding. Due to engineering needs, some holes are punched in the diaphragm.
From the appearance of geocells, there are several types of geocells, including smooth geocells, perforated geocells, and textured geocells. The quality standards are divided into national standards and non-standards.
The main purpose of geocell
1. Used to stabilize road and railway subgrades.
2. Used for embankment bearing load and shallow water channel management.
3. A hybrid retaining wall is used to prevent landslides and loads.
When encountering soft ground, the use of geocells can greatly reduce the labor intensity of construction, reduce the thickness of the roadbed, the construction speed is fast, the performance is good, and the project cost is greatly reduced.
Besides the substrate structure laid by geosynthetic products, landfill gas, seepage, etc. need to be treated during the landfill process. When selecting geosynthetic materials, the thickness of the garbage layer and the depth of the landfill should be considered, and the landfill gas should be monitored to prevent it from polluting the atmosphere. Landfill gas includes methane, ethane, etc.; leachate mainly includes sewage and rainwater; oil seepage mainly includes oils, such as engine oil, diesel oil, and solvents; seepage includes oil and water, etc. In recent years, my country’s garbage dumps have adopted special environmental protection measures to deal with harmful substances in the garbage; at the same time, various measures have been adopted to isolate and treat harmful substances, such as anti-seepage technology, barrier technology, and biodegradation technology.
The above is the product explanation of geosynthetic materials and the application selection in a landfill. In actual engineering construction, product selection and the combination can be carried out according to the needs to form a multi-dimensional composite anti-seepage and anti-leakage structure. You can also turn to us for professional advice on issues related to geosynthetic products and landfills. We have more than ten years of experience in the manufacture and application of professional geosynthetics products and can provide one-stop services such as product explanations and engineering guidance. We will be very happy to solve engineering problems for you.