Reverse osmosis (RO) is a powe...
Reverse osmosis (RO) is a powerful water purification method that relies on a semi-permeable membrane to separate water molecules from other particles. Various types of RO membranes are used, each designed to offer specific benefits for different applications. The two most common membranes used in RO systems are cellulose acetate (CA) and thin-film composite (TFC).
TFC membranes are highly efficient and superior in performance, making them the most widely used type of RO membranes. These membranes comprise a thin, dense polyamide layer on a porous support, which effectively rejects salts and impurities. Although CA membranes offer better resistance to chlorine, TFC membranes are preferred for their higher rejection rates of dissolved solids.
Understanding the differences between RO membrane types is crucial for selecting the right system for your needs. While each type has its advantages, knowing which one fits your water quality requirements can make all the difference in achieving optimal purification results.
Reverse osmosis (RO) is a widely used water purification technology that removes contaminants from water by applying pressure to a solution and forcing water molecules through a semi-permeable membrane.
Reverse osmosis works by forcing water through a semi-permeable membrane using pressure. The membrane allows water molecules to pass through but blocks larger molecules like salts and impurities.
This process starts with pre-treated feed water that goes through multiple stages to remove suspended particles. The applied pressure must be higher than the osmotic pressure to allow desalinated water to pass through the RO membrane. The clean water collected on the other side is called the permeate, and the concentrated impurities left behind are called the concentrate.
RO systems consist of several critical components that work together to purify water. Pre-treatment systems remove particulates and chlorine. This protects the membrane from fouling and damage. High-pressure pumps apply the necessary pressure required to push water through the membrane. The RO membrane, often spiral-wound, is the core component where separation occurs.
Additionally, systems have post-treatment units to polish the permeate, ensuring it meets quality standards. Concentrate valves control the wastage of concentrated impurities. Lastly, storage tanks keep the purified water ready for use.
Choosing the correct RO membrane is essential for effective water treatment. Different membranes are designed for varying types of feed water, contaminants, and desired water quality.
For residential systems, membranes are rated based on their daily production capacity, such as 25, 50, or 100 gallons per day. Industrial applications may require membranes that handle higher volumes and more complex contaminants. Besides capacity, the chemical resistance and lifespan of the membrane are crucial factors to consider.
Using the right membrane ensures efficient operation, high-quality permeate, and minimal maintenance issues. Membrane technology has advanced to offer better performance and longevity, aiding RO systems to meet diverse water purification needs efficiently.
PP filter (also known as melt-blown filter) is a non-toxic and odorless polypropylene as raw material, through heating and melting, spinning, traction, acceptance and forming made of tubular filter. The pp filter element has a deep filter structure of uniform pore size, is thin outside and dense inside, and has excellent characteristics of high filtration efficiency and acid and alkali resistance. It can effectively remove impurities such as suspended matter, particles, and rust in the liquid.
Function: (generally only used for coarse filtration with low requirements to remove sediment, rust, and other large particulate matter in water);
Features:
(1) The diameter of the filter element is dense and uniform, and the filtration efficiency is high. Because the particles will bridge in the filter hole, the particles smaller than the hole can also be blocked, and the filtration efficiency is more than 98%.
(2) Its own cleanliness is high, no pollution to water quality.
(3) It is resistant to acid, alkali and other chemical reagents and organic solvents corrosion.
(4) Its strength is large, when the filter inlet and outlet pressure difference is 0.4mpa, the filter element is not deformed. Can be lined with polyvinyl support (or stainless steel skeleton) when the pressure is high
(5) It is cheap, mostly used for the first level of filtration, one-time use.
Granular activated carbon (abbreviated UDF) is made from coconut shell and fruit shell as raw materials through a series of production processes. It is black in appearance, granular, and has the advantages of developed void, good adsorption performance, economics, and durability.
Function: decolorization and filtration, high adsorption rate, good strength, easy regeneration, durability and so on. It can effectively remove odors and different colors in water, drug residues, heavy metals, and various other odors. Can effectively help people get rid of carcinogens. Make the water clear, soft taste, taste sweet.
Life of granular activated carbon: generally 8-12 months. It depends on the local water quality and water consumption.
Compressed activated carbon (abbreviated CTO) is made from powdered raw activated carbon and binder through kneading, extrusion molding, carbonization, activation and other processes.
Function: Deep-level absorption of different colors, odors, residual chlorine, halogenated hydrocarbons, and organic substances harmful to the human body can effectively improve the taste of the effluent. The long-life compressed activated carbon rod and the mesh fabric structure with high contaminant capacity make the filter element have dual-function filtration performance.
Life of compressed activated carbon: generally 8-12 months. It depends on the local water quality and water consumption.
Precision of compressed activated carbon: 5 microns -30 microns
The main material of ultrafiltration membrane (abbreviated UF) is PAN (polyacrylonitrile).
Features:
(1) Has excellent chemical stability, acid resistance, alkali resistance and hydrolysis resistance, can be widely used in various fields;
(2) The membrane filament has good strength and flexibility;
(3) After hydrophilic modification, the water production is large and has a strong anti-pollution;
(4) The membrane filament formula material is less, the process is easy to control, and there will be no phenomenon of PVC raw material formula material, which will lead to the odor problem of the film itself.
Functions: There are about 6 billion 0.01 micron micropores on the wall of each meter-long ultrafiltration membrane, whose pore size only allows water molecules, beneficial minerals and trace elements in water to pass through, and the volume of the smallest bacteria is above 0.02 micron, so bacteria and colloids, rust, suspended matter, sediment, macromolecular organic matter and so on, which are much larger than bacteria, can be intercepted by the ultrafiltration membrane. Thus the purification process is achieved.
The life of ultrafiltration membrane: small, generally 1-2 years, pipe ultrafiltration, and large generally 3-5 years, according to the local water quality and water consumption.
Ultrafiltration membrane accuracy: 0.001 micron -0.01 micron
Reverse osmosis membrane (abbreviated RO membrane) The general flow of water is from low concentration to high concentration; once the water is pressurized, it will flow from high concentration to low concentration, which is the reverse osmosis principle. Because the pore size of the RO membrane is five-millionths of the hair (0.0001 microns), generally can not be seen by the naked eye; bacteria, and viruses are 5000 times of it, therefore, only water molecules and some of the mineral ions beneficial to the human body can pass, the wastewater pipe discharges other impurities and heavy metals
Function: RO membrane can effectively remove calcium, magnesium, bacteria, organic matter, inorganic matter, metal ions and radioactive substances from water
The life of RO film: generally 2-3 years. Depends on local water quality and water consumption
RO film accuracy: 0.0001 microns (0.1 nm)
Reverse osmosis (RO) membranes are widely used due to their efficiency in purifying water and their role in numerous industries. This section concentrates on how RO systems are applied, especially in drinking water purification.
Reverse osmosis is critical for producing clean drinking water. It is highly effective in removing impurities like salts, bacteria, and viruses. This makes RO systems essential in areas with water contamination issues.
RO filters are commonly used in both household water filtration systems and large municipal water treatment plants. By forcing water through a semipermeable membrane, harmful contaminants are blocked, ensuring safe and clean drinking water.
Advantages:
Challenges:
Waste Water: For every gallon of purified water, several gallons of waste water can be produced.