Sustainable Approach on the Treatment of Textile Wastewater …
91
2 Membrane Separation Process
Membrane technology is one of the most encouraging methods for purification of
wastewater and it also enhances the production of high grade water quality [17].
Membrane separation process utilizes a membrane which in turn acts as a semipermeable barrier to effect the separation of two or more components. This membrane
hinders the motion of chemical species either in partial or total manner [18].
Membrane technology has been widely utilized to isolate fluid/fluid or fluid/strong
blends because of the adaptability and capacity to eliminate the contaminant from
wastewater to low levels [19]. Separation processes by employing membranes
have shown powerful exhibitions in desalination, recovery and water treatment
applications [20].
Membrane technology allows us to separate very small size particles to the molecular and ionic level. This is in turn similar to the conventional separation systems also
called as dead end filtration, where we employ filtration to separate suspended particles that are typically larger than 10 µm. In this process, the particles are retained by
the filter and they in turn build up with time as a cake layer resulting in the increased
resistance to filtration. The common requirements include frequent cleaning and
replacement of the filters. In this method, gravity is the main force for separation to
take place, and here, the feed flows in a perpendicular direction to the filter medium.
This system remains open to the atmosphere.
Thin membrane filters are generally employed for the purpose of separation
to occur. The liquid is made to flow under pressure and it is forced to flow
along the surface of the membrane. The commonly used membrane technologies
include microfiltration, ultrafiltration, nanofiltration, reverse osmosis. Membranes
possessing antifouling and self-cleaning properties can be a more powerful and an
eco-friendly methodology [21].
The most commonly used membrane system used in food industry includes microfiltration, ultrafiltration, nanofiltration and reverse osmosis. These systems are differentiated based on their membrane pore size. The smallest pore size is for reverse
osmosis ranging from 10
−4 to 10
−3
µm. For nanofiltration membranes, the pore size
varies from 10
−3 to 10
−2 . For ultrafiltration, the pore size varies from 10
−2 to 10
−1 .
The microfiltration has the largest pore size ranging anywhere from 10
−1 to 10
1
µm.
Also, the pressure used in these systems varies, fairly the pressure used in microfiltration is around 1 bar, ultrafiltration requires around 1–12 bars, nanofiltration requires
10–40 bars, and in reverse osmosis, we require very high pressures ranging from 30
to 60 bars (Fig. 1).
3 Microfiltration
Microfiltration is often used to remove bacteria and to separate a larger size molecule.
They are commonly used in skimmed milk to reduce bacteria, whey, brine, and it
91
2 Membrane Separation Process
Membrane technology is one of the most encouraging methods for purification of
wastewater and it also enhances the production of high grade water quality [17].
Membrane separation process utilizes a membrane which in turn acts as a semipermeable barrier to effect the separation of two or more components. This membrane
hinders the motion of chemical species either in partial or total manner [18].
Membrane technology has been widely utilized to isolate fluid/fluid or fluid/strong
blends because of the adaptability and capacity to eliminate the contaminant from
wastewater to low levels [19]. Separation processes by employing membranes
have shown powerful exhibitions in desalination, recovery and water treatment
applications [20].
Membrane technology allows us to separate very small size particles to the molecular and ionic level. This is in turn similar to the conventional separation systems also
called as dead end filtration, where we employ filtration to separate suspended particles that are typically larger than 10 µm. In this process, the particles are retained by
the filter and they in turn build up with time as a cake layer resulting in the increased
resistance to filtration. The common requirements include frequent cleaning and
replacement of the filters. In this method, gravity is the main force for separation to
take place, and here, the feed flows in a perpendicular direction to the filter medium.
This system remains open to the atmosphere.
Thin membrane filters are generally employed for the purpose of separation
to occur. The liquid is made to flow under pressure and it is forced to flow
along the surface of the membrane. The commonly used membrane technologies
include microfiltration, ultrafiltration, nanofiltration, reverse osmosis. Membranes
possessing antifouling and self-cleaning properties can be a more powerful and an
eco-friendly methodology [21].
The most commonly used membrane system used in food industry includes microfiltration, ultrafiltration, nanofiltration and reverse osmosis. These systems are differentiated based on their membrane pore size. The smallest pore size is for reverse
osmosis ranging from 10
−4 to 10
−3
µm. For nanofiltration membranes, the pore size
varies from 10
−3 to 10
−2 . For ultrafiltration, the pore size varies from 10
−2 to 10
−1 .
The microfiltration has the largest pore size ranging anywhere from 10
−1 to 10
1
µm.
Also, the pressure used in these systems varies, fairly the pressure used in microfiltration is around 1 bar, ultrafiltration requires around 1–12 bars, nanofiltration requires
10–40 bars, and in reverse osmosis, we require very high pressures ranging from 30
to 60 bars (Fig. 1).
3 Microfiltration
Microfiltration is often used to remove bacteria and to separate a larger size molecule.
They are commonly used in skimmed milk to reduce bacteria, whey, brine, and it