How to Classify of Membranes in WWTP Based on Chemical nature?
Membrane technology can treat a wide range of wastes, including sanitary landfill leachate containing both organic and inorganic chemical species, water-soluble oil wastes used in the metal fabricating and manufacturing industries, solvent-water mixtures, and oil-water mixtures generated during metal fabricating facility washing operations.
Membrane processes can be classified into sub-processes based on the material used for the membrane, the nature of the driving force, and the separation mechanism, such as reverse osmosis (RO), electrodialysis (ED) or electrodialysis reversal (EDR), microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF).
Pressure is used to transfer water through the membrane in RO, MF, UF and NF. As water passes across the membrane, MF eliminates particle debris, whereas RO removes numerous solutes. Large particles and bacteria are often rejected by MF membranes, which have the biggest pore size. Because UF membranes have narrower holes than MF membranes, they can reject bacteria and soluble macromolecules like proteins in addition to big particles and germs. RO membranes are virtually non-porous, allowing particles and even numerous low-molar-mass species like salt ions and organics to pass through. NF membranes, also known as loose RO membranes, are a relatively novel kind of membrane.
Rising regulatory pressure to deliver higher quality water, increased demand for water necessitating the use of low quality water resources as a source, and the development and commercialization of membrane processes are the driving reasons behind the usage of membrane technology.
Membrane operation provides the following advantages-
- Separation occurs at room temperature with no phase change.
- There is no product build-up inside the membrane (unlike ion exchange resins, which require replacement/regulations).
- Chemical additives are not required for separations.
Membrane classification: Based on Chemical nature
Organic (polymers) membranes and inorganic membranes composed of metals, ceramics, glasses, and other materials are classed/ based on the chemical composition of the substance utilized for the membrane.
a) Membranes made of polymer (organic)
The usage of cellulose and its derivatives has increased. These hydrophilic polymers are inexpensive and have modest adsorption characteristics. After cellulose diacetate, polyamides (hydrophilic polymers) are the second class of polymer (aromatic polyamides) utilized to make membranes. It outperforms cellulose esters in terms of thermal, chemical, and hydraulic stability. Because the amide group (-CO-NH-) cannot tolerate even a trace of Cl2, they are incompatible with chlorinated water. In UF, but not in RO, polyacrylonitrile (PAN) is employed.
b) Membranes made of inorganic materials
In comparison to polymer materials, these membranes exhibit higher thermal, chemical, and mechanical stability. This membrane has the drawback of being fragile and more costly. Metal oxides, nitrides, and carbides, such as Al, Zr, and Ti, are used to make ceramic membranes.
Membrane techniques for wastewater treatment are becoming more popular across the world as the cost of the procedure decreases and the cost of water rises. Membrane procedures accounts for over 70% of the total installed capacity of desalination across the world, and the percentage is growing (for drinking water).
In Japan, more than 30 MLD of wastewater is used in constructing toilet flushing water. It's used in a lot of industrial wastewater treatment plants to make reusable grade water out of the effluents. Membrane technologies should be adopted worldwide and that is what we are trying to do at Netsol Water Solutions.
How can Netsol Water help?
If you need help designing an efficient membrane technology equipment such as RO, contact Netsol Water. We are the leading manufacturers of the RO plants. We can provide you with design calculations, budgetary expenses, preliminary layouts, and a lifetime cost analysis.