physicochemical process parameters. These factors give rise to total membrane
resistance (R t ). Further, it can be calculated by using the following relation.
MS e ¼ 1 À
P c
F c
ð1Þ
where MS e represents the membrane separation efficiency (%), P c the permeate
concentration (mg/L), and F c the feed concentration (mg/L).
The membrane separation efficiency lies in between 50 and 90% for various
industrial processes. The total membrane resistance can be calculated by using the
following relation.
R t ¼ R r þ R ir
ð2Þ
where R r represents the reversible membrane resistance and R ir the irreversible
resistance. The reversible and irreversible resistances are also due to the reversible
and irreversible membrane fouling, respectively. The reversible fouling as can be
deciphered from the name is removable by simple hydraulic washings. However,
irreversible fouling, as the name suggests, is difficult to get rid of from the membranes and lastingly adds to the total membrane resistance.
There are two types of flow patterns and filtration arrangements in UF and MF
membranes as shown in Fig. 2 [1]:
Dead-End Filtration In a dead-end filtration system, the feed flow is perpendicular
to the membrane surface. The solute or the rejected particles remain on the membrane, forming a gel or cake layer. This phenomenon enhances the accumulation of
particles on the membrane surface and causes increase in membrane resistance. The
resistance can only be minimized by applying pressure to maintain the flow.
Fig. 2 Schematic representation of flow pattern of membrane separation processes
6
R. Singh et al.
resistance (R t ). Further, it can be calculated by using the following relation.
MS e ¼ 1 À
P c
F c
ð1Þ
where MS e represents the membrane separation efficiency (%), P c the permeate
concentration (mg/L), and F c the feed concentration (mg/L).
The membrane separation efficiency lies in between 50 and 90% for various
industrial processes. The total membrane resistance can be calculated by using the
following relation.
R t ¼ R r þ R ir
ð2Þ
where R r represents the reversible membrane resistance and R ir the irreversible
resistance. The reversible and irreversible resistances are also due to the reversible
and irreversible membrane fouling, respectively. The reversible fouling as can be
deciphered from the name is removable by simple hydraulic washings. However,
irreversible fouling, as the name suggests, is difficult to get rid of from the membranes and lastingly adds to the total membrane resistance.
There are two types of flow patterns and filtration arrangements in UF and MF
membranes as shown in Fig. 2 [1]:
Dead-End Filtration In a dead-end filtration system, the feed flow is perpendicular
to the membrane surface. The solute or the rejected particles remain on the membrane, forming a gel or cake layer. This phenomenon enhances the accumulation of
particles on the membrane surface and causes increase in membrane resistance. The
resistance can only be minimized by applying pressure to maintain the flow.
Fig. 2 Schematic representation of flow pattern of membrane separation processes
6
R. Singh et al.