Awareness of the effects of human development activities on the environment is fostering a wider movement associated with making sustainable decisions for our future.
Geomembranes: an overview
Geomembranes are impermeable liners or barriers made from flexible synthetic sheets used in conjunction with other geosynthetics or any geotechnical material – such as rocks or earth – to control fluid or gas migration in human-made projects, structures, or systems.
Simply put, a geomembrane liner is a geosynthetic hydraulic barrier, used whenever there is a loss of material that must be stopped or prevented, be it clean water, hazardous materials or any other substance that should not escape from its designated space. That said, geomembranes are extremely useful to prevent a hazard from occurring.
Geomembranes are becoming increasingly popular nowadays, even though they actually have been around for more than 50 years. As environmental concerns grow and become more important, these lining systems provide a practical solution for waste containment, especially considering the need for water quality improvement resources all across the globe. However, despite its extensive use, not many people know what geomembranes really have to offer.
Key Applications for Geomembranes
Due to their optimal resistance to humidity and waste settlement, geomembranes have dozens of varied and fascinating applications, including:
- Solid and liquid waste containment
- Landfill caps/closures
- Waterproof protection beneath asphalt in roads and highways
- Tunnel liners
- Waterproof facing for dams
- Coal ash containment
- Aquaculture, raising fish
- Transportation of liquids in trucks
Even though geomembranes are being used in environmental, hydraulic, transportation and gas applications as well as in the waste industry (and new uses are being discovered all the time!), the market is mainly driven by the increased demand of them in the water management and mining industry.
Types of Geomembrane Materials
As with any versatile product, geomembranes could be made from a comprehensive range of lining materials, each with its own set of unique characteristics and mechanisms.
Therefore, before choosing, it is recommended to look at the overall application of each one, do a little research about its properties, the liner life expectancy, and other important factors. The selection of the correct material is vital to the performance of the geomembrane system.
That said, the market is currently divided between HDPE (High Density Polyethylene), LLPDE (Low Linear Density Polyethylene), PP (Polypropylene) & PVC, among others.
- HDLPE and LLPDE membranes are currently the most widely proposed geomembranes for containment of hazardous and wastes managment related applications and capping in landfills and mining operations, as they offer superior strength, outstanding elongation, and are resistant to a wide range of chemicals and puncture. hdpe geomembranes are generally available and economically superior thanks to its relatively straightforward manufacturing process, which has kept prices low compared to other types of geomembranes.
- PVC is a highly flexible thermoplastic geomembrane made from a mixture of vinyl compounds, plasticizers, and stabilizers. PVC geomembranes have been proven especially effective in dealing with containment of hazardous and wastes to preserve potable water sources.
- PP (Polypropilene) geomembranes, on the other hand, could be more expensive to install than other liners but are easier to install and repair after aging. PP geomembranes are extremally durable products, especially designed to be left expose. They also have superior UV and Ozone resistance, as well as good chemical resistance. Popular applications include (but are not limited to) stormwater management systems, landfills, and coal ash ponds.
Geomembranes are available in a variety of structures and compositions, and their size is fully adjustable, which means they can be factory fabricated into small or large panels. If bigger geomembranes are needed, they can be easily welded in the field by using specific materials, or even thermally or chemically fused for strength and durability by a certified technician.
There are many important factors when it comes to the installation of a geomembrane lining system. It is a complex process that is generally performed by certified engineers and technicians. To ensure the proper installation of any geomembrane lining system some key factors are required, including site preparation, specialized welding technics, quality assurance and control, leak detection, standards, recommendations, and regulations.
Thanks to technological advancements, geomembranes are nowadays manufactured from exceptionally durable materials, often with an expected lifetime of hundreds of years. This high service life potential makes geomembranes a powerful tool to promote environmental protection and sustainability.
Sustainable solutions are the key to a better future. It is extremely important to use the environment and its resources rationally and wisely in order to maintain the quality of life on our planet.