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cation- selective membranes are negatively charged and repel anions, allowing flow
of cations only (Satapathy and Natarajan 2006).
8.3.4 Coagulation/Flocculation
Coagulation is a chemical process in which a chemical (coagulant) is added into
water. These coagulants cling the colloid material in the water, making small masses
of the “flocs.” The suspended matter is caught by flocs and hence removed easily
(Sillanpää et al. 2018).
Flocculation is a slow gentle mixing of the water to aid the flocs to develop and
grow in size as well which settle down easily leaving clear water behind. The basic
mechanism that removes the organic contaminants by coagulation was studied by
Fernandez and coworkers (Fernandez et al. 1997), while Kuo et al. studied the influence of various controllable parameters including initial pH, turbidity, and per ozonation doses as well as flocculation time on the removal of organic material dissolved
in water during alum coagulation. (Kuo and Amy 1988).
8.3.5 Ultrafiltration
The principle behind ultrafiltration is size exclusion; in this process, simple mechanical (pressure) filtration is done using membranes with pore size ranging from 0.1 to
0.001 μm. This process removes colloids, high molecular weight molecules, as well
as organic and inorganic molecules. When pressure is applied, water and low
molecular weighted substances pass through the filter membrane, while colloids
and macro-solutes are retained by the membrane. Factors affecting this efficiency of
filtration include surface chemistry of particles as well as the membrane itself and
their electrical charges (Landaburu-Aguirre et al. 2009).
8.3.6 Membrane Filtration
This method has gained great deal of consideration for water remediation since it is
not only used to remove inorganic effluent and suspended particulates (organic and
inorganic) but also effectively utilized for heavy metal treatment. Various types of
membrane filters are used these days such as ultrafiltration and nanofiltration membranes depending upon the size of particle that can be engaged. These unique specialties of the ultrafiltration enable the passage of low molecular weight solutes
while blocking macromolecules, whose size is larger than membrane pore’s size.
A. Sabir et al.
cation- selective membranes are negatively charged and repel anions, allowing flow
of cations only (Satapathy and Natarajan 2006).
8.3.4 Coagulation/Flocculation
Coagulation is a chemical process in which a chemical (coagulant) is added into
water. These coagulants cling the colloid material in the water, making small masses
of the “flocs.” The suspended matter is caught by flocs and hence removed easily
(Sillanpää et al. 2018).
Flocculation is a slow gentle mixing of the water to aid the flocs to develop and
grow in size as well which settle down easily leaving clear water behind. The basic
mechanism that removes the organic contaminants by coagulation was studied by
Fernandez and coworkers (Fernandez et al. 1997), while Kuo et al. studied the influence of various controllable parameters including initial pH, turbidity, and per ozonation doses as well as flocculation time on the removal of organic material dissolved
in water during alum coagulation. (Kuo and Amy 1988).
8.3.5 Ultrafiltration
The principle behind ultrafiltration is size exclusion; in this process, simple mechanical (pressure) filtration is done using membranes with pore size ranging from 0.1 to
0.001 μm. This process removes colloids, high molecular weight molecules, as well
as organic and inorganic molecules. When pressure is applied, water and low
molecular weighted substances pass through the filter membrane, while colloids
and macro-solutes are retained by the membrane. Factors affecting this efficiency of
filtration include surface chemistry of particles as well as the membrane itself and
their electrical charges (Landaburu-Aguirre et al. 2009).
8.3.6 Membrane Filtration
This method has gained great deal of consideration for water remediation since it is
not only used to remove inorganic effluent and suspended particulates (organic and
inorganic) but also effectively utilized for heavy metal treatment. Various types of
membrane filters are used these days such as ultrafiltration and nanofiltration membranes depending upon the size of particle that can be engaged. These unique specialties of the ultrafiltration enable the passage of low molecular weight solutes
while blocking macromolecules, whose size is larger than membrane pore’s size.
A. Sabir et al.