Polymeric membranes include ultrafiltration (UF), nano-filtration (NF), micro-filtration (MF), reverse osmosis (RO), which have many applications in water and wastewater industries. Using these processes because of their advantages such as reduced energy consumption, high efficiency mass transfer and ease of use, are of great importance in various industries such as water and wastewater treatment plants and industrial effluents such as petroleum wastewater treatment. Different types of membrane filters are exist on global market that are producing by different manufacturers with different brands. Today, all around the world membrane fitlers can be found in huge varieties.
What is membrane and its types?
In a general definition, the membrane is defined as the phase at which dissociated components pass through the solution at different speeds. In this process, there is usually no phase change and the products can be merged together. The driving force required in the membrane process can be the difference of concentration, pressure, temperature and electrical potential. The simplest types of membranes are based on particle size differences that are similar to filters, but membranes differ in terms of pore size and size distribution as well as flow. Membrane performance is determined by two parameters, which include membrane discharge and membrane selectivity.
Types of major membrane separation processes include microfiltration, ultrafiltration, nano-filtration, reverse osmosis, electrodialysis, gas separation and evaporative seepage. In recent years, Increased attention to environmental protection, the demand for clean water and high energy efficiency have increased the use of these membrane processes. In the meantime, reverse osmosis, nano-filtration, ultrafiltration are a variety of membrane purification methods that perform separation phase based on pressure difference and are used in water and wastewater treatment processes.
Applications of Membrane Processes in Water and Wastewater Treatment:
- Surface and groundwater disinfection
- Industrial water production from surface water (removal of suspended solids and colloids)
- Production of wastewater effluent from municipal / industrial wastewater treatment plants
- Drinking water treatment to remove suspended solids, viruses, dyes and some excellent materials.
There are different types of membrane filtration methods around the world and today you can find membrane filter diagram all around the world easily.
What is a filter membrane?
Membrane processes have grown late in industrial processes. Microfiltration membranes were commercially produced for use in bacteriology laboratories in the late second decade of the 20th century. It was not possible to use reverse-osmosis and large-scale ultrafiltration until such asymmetric filters were created. Right after World War II, a special group was formed to study German membrane technology, and in 1947 to 1950 successful membrane structures were developed.
In 1957, the result of many research reports led to the decision to use a membrane filter method for drinking water. During the first century of development and development of membrane filters, researchers used membranes for dialysis, osmotic and ultrafiltration studies. Membranes can be segmented from different perspectives. By the nature of the membranes, they can be divided into two parts:
- Natural membranes : There are membranes that exist in nature, like the body cells of living things.
- Synthetic membranes : Which are made in artificial ways.
The second group of mineral membranes (such as zeolite or amorphous silica), which are divided into four major groups:
- Ceramic membranes
- Metal Membranes
- Zeolite membranes
- Glass membranes
An important characteristic of inorganic membranes is the chemical and thermal stability of organic membranes.
ow many types of RO membranes are there?
In recent 30 years, Newest models and varieties of membranes are produced that each of them has different usages in various industries. One of the most important uses of RO membranes is in the oil refineries. There are some membrane filters that are used while refining raw oil. Variety of membrane filters now on the market is too high and there are too many different producers around the world that are producing and exporting various types of membrane filters.
Filters are made of different types of materials and in different ways. Today, membrane separation occurs in the following areas, which are mainly divided into four subgroups due to the size of the membrane cavities. Microfiltration, Ultrafiltration, Nanofiltration, Reverse Osmosis. For having information about all of the membrane filters on the market you can search for it on the internet or talk with some one expert in this field.
Best membrane fitlers for water treatment
As it was said and mentioned above, there are various types of membrane filters on the market and the most consumption of membrane filters is in water treatment systems. Nanofiltration is one of the types of membrane filtration methods capable of removing particles larger than 1 nm (10 angstroms). Nanofiltration is one of the membrane purification methods that eliminates many compounds with high molecular mass and water soluble. Nanofiltration membranes remove the hardness of water except for low molecular mass ions that are beneficial to the human body.
Nano membrane filters are the best filters for water treatment systems. Principle of membrane filtration on each systesm are different.
What is not removed by reverse osmosis?
Reverse osmosis is a method in which water, with increasing pressure, passes through a semiconductor membrane of reverse osmosis and its ions and minerals are removed. Osmosis is a natural process in which water flows without energy. The reverse osmosis membrane is a semipermeable membrane that allows water molecules to pass through, but prevents the passage of substances such as soluble salts, organic matter, bacteria, and so on. For the water to pass through the membrane, there is a need for greater pressure than the osmotic pressure created by the difference in concentration of the solutions on the thicker side of the solution.
What are membrane filters made of?
In today’s global market there are so many different membrane filter producers, they use different methods and raw materials for producing membrane filters and day by day these methods and raw materials are changing. Membrane filtration uses is also increasing day by day.
As mentioned above, filters are divided into three major groups according to their pore size: Micro-filters, Ultra filters and Nano-filters.
Nano-filters are essentially low-pressure filtration, Therefore, the cost of nanofilters and their energy consumption are lower than the other two methods. Nanotechnology means making atoms and molecules to produce new materials, devices and technologies.
Is it safe to drink reverse osmosis water?
In the water treatment by the reverse osmosis method, any chemical materials do not be use, so that it is safe to drink the water that is treated by reverse osmosis filtration systems. In this method an special membrane filtration unit makes to water safe to use and drink.