unicellular parasites which causes severe diarrhea and systemic illness in person with
acquired immunodeficiency syndrome (AIDS) [21]. Helicobacter pylori are intestinal bacteria which have been classified as carcinogenic pathogen by WHO [22]. The
microorganism, namely, Legionella, grows in piped water distribution systems,
whereas guinea worm (Dracunculus medinensis) occurs in many water sources
[23]. The water contaminants are not easily detected through naked eye, odor, and
taste. The microorganisms which are present in water may be beneficial or harmful to
human health [1]. Sometimes the very tiny level of microorganisms (Escherichia
coli, Giardia, Cryptosporidium) is more dangerous [24–26]. All peoples are not
equally affected from the contaminated water; it may depend on the individual health
conditions. People with weak immune system particularly infants, young children,
pregnant women, old age people and immune suppressive therapy patients, AIDS
patients, cancer patients, and organ transplant patients are more vulnerable to the
waterborne pathogens [27].
In general, the bacteria are consisting of cell membrane, cell wall and cytoplasm.
Gram-positive and gram-negative bacteria are the two major types which presents in
the contaminated water. The gram-positive bacteria have one cytoplasmic membrane
with a multilayer of peptidoglycan polymer and a thicker cell wall (20–80 nm),
whereas gram-negative bacteria wall is composed of two cell membranes, an outer
membrane, and a plasma membrane with a thin layer of peptidoglycan with a
thickness of 7–8 nm. The bacterial cells range from about 1–10 μm in length and
0.2–1 μm in width, while the viruses are 100 times smaller than bacteria at
0.004–0.1 μm in size. The protozoan cysts are approximately 2–50 μm in diameter
[1]. The microorganisms present in the drinking water can be removed or destroyed
by various water purification techniques.
3 Water Purification Techniques
There are many well-established techniques available to purify the water, namely,
chlorination, membrane distillation, ultraviolet light, ozonation, electrodialysis, ion
exchange, etc. [28]. The chlorination process is inexpensive, is easy to handle,
destroys the bacteria, and gives long-term protection. The main disadvantage of
using chlorine for water treatment is that it easily reacts with organic matters like iron
and manganese, even at low concentration which leads to form carcinogenic
by-products [29]. The chlorination process destroys the bacteria only at higher
level concentration of chlorine which may lead to unpleasant odor and taste of
water. The distillation process is one of the most effective methods to purify the
contaminated water. The distillation process involves no chemicals but is expensive
and has longer process, and mainly the storage of distilled water affects its quality.
Ultraviolet light disinfection unit is not used separately; it may be used with
mechanical filters, activated carbon filters, reverse osmosis, and water softeners. In
ozonation process, ozone is unstable, and it also provides more powerful disinfectant
than chlorine. The water treatment process includes sedimentation, precipitation,
Biopolymer-Based Nanofibrous Membrane for Water Purification Treatment
229
acquired immunodeficiency syndrome (AIDS) [21]. Helicobacter pylori are intestinal bacteria which have been classified as carcinogenic pathogen by WHO [22]. The
microorganism, namely, Legionella, grows in piped water distribution systems,
whereas guinea worm (Dracunculus medinensis) occurs in many water sources
[23]. The water contaminants are not easily detected through naked eye, odor, and
taste. The microorganisms which are present in water may be beneficial or harmful to
human health [1]. Sometimes the very tiny level of microorganisms (Escherichia
coli, Giardia, Cryptosporidium) is more dangerous [24–26]. All peoples are not
equally affected from the contaminated water; it may depend on the individual health
conditions. People with weak immune system particularly infants, young children,
pregnant women, old age people and immune suppressive therapy patients, AIDS
patients, cancer patients, and organ transplant patients are more vulnerable to the
waterborne pathogens [27].
In general, the bacteria are consisting of cell membrane, cell wall and cytoplasm.
Gram-positive and gram-negative bacteria are the two major types which presents in
the contaminated water. The gram-positive bacteria have one cytoplasmic membrane
with a multilayer of peptidoglycan polymer and a thicker cell wall (20–80 nm),
whereas gram-negative bacteria wall is composed of two cell membranes, an outer
membrane, and a plasma membrane with a thin layer of peptidoglycan with a
thickness of 7–8 nm. The bacterial cells range from about 1–10 μm in length and
0.2–1 μm in width, while the viruses are 100 times smaller than bacteria at
0.004–0.1 μm in size. The protozoan cysts are approximately 2–50 μm in diameter
[1]. The microorganisms present in the drinking water can be removed or destroyed
by various water purification techniques.
3 Water Purification Techniques
There are many well-established techniques available to purify the water, namely,
chlorination, membrane distillation, ultraviolet light, ozonation, electrodialysis, ion
exchange, etc. [28]. The chlorination process is inexpensive, is easy to handle,
destroys the bacteria, and gives long-term protection. The main disadvantage of
using chlorine for water treatment is that it easily reacts with organic matters like iron
and manganese, even at low concentration which leads to form carcinogenic
by-products [29]. The chlorination process destroys the bacteria only at higher
level concentration of chlorine which may lead to unpleasant odor and taste of
water. The distillation process is one of the most effective methods to purify the
contaminated water. The distillation process involves no chemicals but is expensive
and has longer process, and mainly the storage of distilled water affects its quality.
Ultraviolet light disinfection unit is not used separately; it may be used with
mechanical filters, activated carbon filters, reverse osmosis, and water softeners. In
ozonation process, ozone is unstable, and it also provides more powerful disinfectant
than chlorine. The water treatment process includes sedimentation, precipitation,
Biopolymer-Based Nanofibrous Membrane for Water Purification Treatment
229