Global water consumption has almost six doubled since 1920. And it is still on the increase as a result of rapid population growth, advanced industrialization, and under the influence of climate changes. But with ceramic membranes, we can purify and recycle our scarce water resources. However, multiple types of ceramic membrane support exist, and it can be difficult to figure out their unique advantages, how they filter, and which membrane supports are most suitable for which water treatment applications. Let us dive into the details of the different ceramic membrane support designs.
Tubular membranes are the most common ceramic membranes. These are designed for the removal of suspended solids, oil droplets, and oil emulsions. Tubular membranes are ideal for produced water in the oil and gas market as well as industrial wastewater treatment. This membrane is designed as a long tube and is coated on the inside of the membrane. Learn more about membrane coating here. There are two types of tubular membranes; a honeycomb structure, which is a ceramic membrane with several parallel flow channels, and a monotube structure, which is a ceramic membrane with one large flow channel. Of all ceramic membranes, the honeycomb membrane with 30 flow channels is the most popular membrane type. Due to the many flow channels of the ceramic membrane, this membrane provides a large membrane surface area of 0.33 m² for liquid filtration, making it capable of filtering a great amount of liquid although solely taking up a small footprint. This ensures an extremely efficient and compact water filtration process. Thereby, a whole membrane housing containing 99 ceramic membranes provides a membrane liquid filtration area of an impressive 32 m².
The tubular membrane is typically used for crossflow configuration, which is the filtration type that is used the most. Still, it may also be used as dead-end filtration. Both of these filtration types are denoted inside-out filtration because the liquid is filtered from the inside of the membrane and permeate flows outside. Read more about the membrane filtration principles here.
Several parallel flow channels run through the membrane in a porous support structure in the honeycomb ceramic membrane. Pressure from one end of the membrane will make the feed stream flow through the membrane, and this will be separated into permeate and concentrate. Learn more about how ceramic membranes work here.
Hybrid Technology Membrane
Hybrid technology membranes are a type of tubular membranes, as described above. They take the same form as a tubular membrane, work the same, and are also frequently utilized for crossflow configuration. Still, the conventional ceramic membrane is made of 100 % SiC, while the HTM combines silicon carbide and zirconia (ZrO2) to obtain the best of both worlds.
By combining these durable materials, it is possible to obtain unique and ground-breaking membrane properties. The HTM has a denser pore size of 60 nanometers (NM), making it an ultrafiltration technology. It can thereby filter industrial liquids and wastewater at extremely fine levels, enabling new separation processes and new filtration applications.
Flat Sheet Membranes
Flat sheet membranes are designed for water applications, such as for groundwater and drinking water. This membrane is designed as a rectangular membrane, which is coated on the outside of the membrane. The flat sheet membranes are designed in racks of modules, which can be customized in different rack sizes and different tower heights. This makes the flat sheet membranes highly flexible and stackable. These membranes are ideal for compressing many ceramic membranes into a small footprint.
The flat sheet membranes are designed for submerged outside-in filtration. This type of filtration is denoted outside-in filtration because the liquid is filtered from the outside of the membrane and permeate flows inside. The permeate is led to a permeate tank through two permeate outlets, which are situated at each end of the flat sheet membrane.
The flat sheet membranes are designed into a submerged vacuum-driven filtration system.
They are generally pressureless and submerged into a feed tank. Aided by the water level in the tank, the permeate is sucked out of the racks.
Aqua Solution® Membranes
Aqua Solution® membranes are a unique, patented LiqTech solution designed for liquids with a reduced number of suspended solids. It is highly applicable for pre-treatment for reverse osmosis (RO), wastewater treatment, swimming pools, and spas. The Aqua Solution® membrane is designed as a large pipe with multiple channels and is coated on the inside of the membrane.
Currently, this solution is heavily adopted in swimming pools and spas for several reasons. Firstly, Aqua solution® membranes are part of a compact system design, which reduces footprint by 65 % compared to the conventional sand filter solution. It is possible to optimize your operation or even avoid a renovation or building extension when investing in a new filtration solution with a small footprint. Secondly, conventional technologies utilize large amounts of chemicals for disinfection. Aqua Solution® membranes heavily reduce the amount of chemicals, which ultimately provides a healthier pool and spa environment. Thirdly, Aqua Solution® membranes offer high efficiency and lowered life cycle costs, enabling you to reduce backwash costs, electricity, chemicals, and maintenance. This thereby brings forth a more cost-efficient filtration process in comparison to other filtration solutions. Aqua Solution® membranes are, therefore, the perfect alternative to sand filters in pool and spa installations.
The Aqua solution® membrane is utilized as a dead-end filtration solution. This type of filtration is denoted inside-out filtration because liquid is filtered from the inside of the membrane and permeate flows outside.
Ceramic Disc Membranes
The disc membranes are designed to remove suspended solids, oil droplets, and process water in wastewater applications. The disc membrane can be utilized for various filtration applications, such as for manure and digester effluent, landfill leachate, galvanic wastewater, water and PEG recovery in the semiconductor industry, oil sludge, and algae concentration. The disc membrane is designed as a circular disc and is coated on the outside of the membrane.
The disc membranes are designed for outside-in filtration. This type of filtration is denoted outside-in filtration because liquid is filtered from the outside of the membrane and permeate flows inside. Through internal permeation flow channels, the permeate is separated.
Through a crossflow effect, rotation of the discs at high velocities enables flow cleaning of the membrane surface. This method delivers energy savings that can exceed 80 % compared to conventional cross flows.
Extreme Durability & Outstanding Lifetime
All LiqTech's ceramic membranes are based on silicon carbide, which is the second hardest material in the world and the hardest human-made material ever made. Learn more about silicon carbide here. This extreme strength provides mechanical, thermal, and chemical strength and durability. The membranes can operate in up to 800 ˚C and are chemical resistant in all pH values from 0-14. This extreme strength provides a long lifetime, making your operation go on and on without any interruptions.
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