Packaged Drinking water

1. Department of food technology ; IUST Awantipora

2. OUTLINE
Packaged drinking water – definition
Types
Manufacturing process
Quality evaluation
 Raw and processed water
 Methods of water treatment.

3. INTRODUCTION :
Water is very essential for mankind. Water available from untreated sources like bore
wells, rivers etc. is not safe for drinking. Thus it is necessary to purify water for drinking
purposes. Safe potable water is not available everywhere. Water is contaminated with
impurities which cause diseases if consumed. Due to this water is processed and
bottled for the use of mankind. Packaged drinking water means water from any potable
water source including public drinking water supply systems which is subjected to
different treatments to meet the various standards and packed.
In India, access to safe drinking water is very difficult to mainly due to over-population
and scarcity of clean water resources. This has resulted in high growth in demand for
packaged drinking water. Though the rural population still does not use packaged water
but as the literacy rate grows and awareness of safe drinking water increases, this
industry will experience a huge boom. Today packaged drinking water is used in offices,
restaurants, railway stations, airport, bus stands, hospitals etc. Though a large number
of units have been established for the production of packaged drinking water but, due
to the ever growing need, there is still a huge gap between the demand and supply of
packaged drinking water

4. Packaged Drinking
Packaged drinking water means water derived from surface water or
underground water or sea water which may be subjected to specified
treatments, namely, decantation, filtration, combination of filtrations,
aeration, filtration with membrane filter, depth filter, cartridge filter,
activated carbon filtration, demineralization, re-mineralization, reverse
osmosis and packed after disinfecting the water to a level that shall not
lead to any harmful contamination in the drinking water by means of
chemical agents or physical methods to reduce the number of
microorganisms to a level beyond scientifically accepted level for food
safety or its suitability: Provided that sea water, before being subjected
to the above treatments, shall be subjected to desalination and related
processes. It shall be filled in sealed containers of various
compositions, forms and capacities that is suitable for direct
consumption without further treatment. In case de-mineralization is
a part of the treatment process, the ingredients used shall be of
food-grade quality and conform to the requirements set by
Food Safety and Standards Authority of India and rules framed
there under.

5. Types
The FDA classifies packaged bottled
water according to its origin. The three
major types of bottled water are :
• Natural Mineral water
• Spring water
• Purified water
• The International Bottled Water
Association considers four
additional categories of bottled
waters (IBWA, 2000): Artisan water,
sparkling water , well water ,
drinking water.

6. • MINERAL WATER :
Bottled water containing not less than 250
parts per million total dissolved solids may be
labeled as mineral water. Mineral water is
distinguished from other types of bottled
water by its constant level and relative
proportions of mineral and trace elements at
the point of emergence from the source. No
minerals can be added to this product.
Mineral water does indeed have some health
benefits , since it provides minerals your body
can’t create on its own. It can also help aid in
digestion, and many people even like the
taste of it over tap water, though that’s down
to personal preference. One of the main
downsides to mineral water is cost, especially
when compared to tap water. Many of the
minerals from this type of water can also be
obtained from a healthy, varied diet.

7. • PURIFIED WATER: Water
that has been produced by
distillation, deionization, reverse
osmosis or other suitable processes
can be labeled as purified bottled
water. Other suitable product
names for bottled water treated by
one of the above processes may
include Distilled water or de-
mineralized water and is one where
the water has been subjected to a
treatment that removes all its
minerals and salt by the process of
reverse osmosis and distillation. It
is an absolutely pure form of water
but it is not typically recommended
for drinking. It can cause mineral
deficiencies because it is devoid of
all salts and most of the natural
minerals in the water are gone as a
result of this process. Drinking this
water may cause rapid sodium,
potassium, chloride, and
magnesium loss.

8. • SPRING WATER: Bottled water derived from an underground formation from which
water flows naturally to the surface of the earth. Spring water must be collected
only at the spring or through a borehole tapping the underground formation finding
the spring.
• DRINKING WATER : r is water that is sold for human consumption in
sanitary containers and contains no added sweeteners or chemical
additives (other than flavours, extracts or essences). It must be calorie-
free and sugar-free. Flavours, extracts or essences may be added to
drinking water comprising less than one-percent-by-weight of the final
product or the product will be considered a soft drink. Drinking water may
be sodium-free or contain very low amounts of sodium.
• WELL WATER: Bottled water from a hole bored, drilled or otherwise constructed
in the ground, which taps the water of an aquifer.

9. • ARTESIAN WELL WATER :
underground layer of rock or
sand) in which Bottled water from
a well that taps a confined aquifer
(water-bearing the water level
stands at some height above the
top of the aquifer. Another name
for bottled water. Accordingly,
drinking water a is water that is sold
for human consumption in sanitary
containers and contains no added
sweeteners or chemical additives (other
than flavors, extracts or essences). It
must be calorie-free and sugar-free.
Flavors, extracts or essences may be
added to drinking water, but they must
comprise less than one-percent weight of
the final product or the product will be
considered a soft drink.
Artesian Aquifer: Cross-section showing an
aquifer tapped by artesian wells. Pressure
within the aquifer forces water up the
wells. The well on the right side of the
diagram is a flowing artesian well that
yields water without pumping. The artesian
well on the left has a water level that is
higher than the top of the aquifer; however,
it is not a flowing artesian well

10. • SPARKLING WATER:
Sparkling water, also known as
seltzer, soda, or tonic water, is
infused with carbon dioxide to
create tons of bubbles and fizziness
at least as much carbonation as the
water contained when it came
from its natural spring. That being
said, any minerals originally
present in the water are often
removed during processing.
Sparkling water is often used as a
healthy substitute for sugary sodas
and other beverages, because it is
lower in calories and sugar, and can
be naturally flavored with healthier
sweeteners and fruit flavoring.
Sparkling water is also often used
in cocktails and other drinks to
create a fizzy sensation on your
tongue.

11. Manufacturing process
RAW MATERIALS :
• Water: Raw water is generally pumped out from the ground.
Municipal water supply may also be used as a source of raw water.
• Chemicals: These are used in the treatment of water. Soluble salts
precipitate over the membranes of Reverse Osmosis (RI)) system and
render them non-functional. Thus antiscalents are used to keep the
membranes from fouling. Ozone gas is used for disinfection.
• Preform- It is a small plastic test tube which expands into a bottle
when hot air is blown Into it. The quality of the bottle depends upon
the quality of the preform. These bottles are for one time use i.e. they
are not refilled. Bottles are generally made in capacities of 1 litrej 1.5
litre and 2 litre.

12. • Cap- Caps are used for sealing the bottles after water is filled into them.
These are reusable 20 litre plastic containers. They are washed and
refilled. The average life of a jar is 40 rounds i.e. they are refilled and used
40 times and then discarded for recycling.
• Jar seal- Similar to the cap of a bottle, it is used to seal the 20 litre
containers. Once the seal is broken, it cannot be used again on a jar. Thus,
every time a jar is refilled a new seal is fitted on it.
• Labels- These are of two types. The bottle labels are thin and circular
which are slid onto the bottle from the top. The jar labels are stickers
which are put somewhere on the body of the jar.
• Miscellaneous: Cartons are brown paperboard containers in which water
bottles are packed (usually 12 bottles) for transportation. Laser ink is fed
into the laser printer which is used for printing batch number on the
neck/bottom of the bottle. After the cartons are filled with bottles, they
are packed and sealed with cellotape.

13. MACHINERY :
Three different machines are involved in the process:
• Preform Blowing Machine:
The preform in passed through a heated chamber which makes it soft. This soft preform is then
picked and put into the blowing chamber where hot air is blown into it and gives it the shape of a
bottle.
• Water purification system:
This includes the sand and carbon filter and the R.O. system. Raw water is processed and finished
water is stored in the stainless steel tank. For every 5000 litres of water produced by the R.O.
system, 3500 litres of waste water is generated. This waste water is recharged back into the ground
via soak pit. The R.O. system can be purchased from various sources.
• Automatic Filling Machine:
This machine comprises of four different sections- suction pump, filling unit, cap feeder and the
conveyor belt. Empty bottles from the blowing machine are fed into a suction pump which pulls
these bottles and pushes them into the filling unit. These empty bottles are washed and filled. The
automatic cap feeder unit feed caps to the filling machine which are then tightened to seal the
bottles. These sealed bottles are queued on the conveyor belt where labels are put and batch
number is printed.

14. Three different
processes are
carried out
simultaneously
within a plant.
Pre-form
Heating
chamber
Hot air blowing
MANUFACTURING PROCESS :
1.The pre-form is passed into a heating chamber to soften it. Hot air is then blown into it
to expand it into a 1 litre bottle

15. Transported
Packing
Visual examination
Filling
Finished water storage
Ozonization
Reverse osmosis
High pressure pump
Sand & Carbon filter
Raw water feed pump dosing system
Raw water storage tank
Raw water

16. 2.Raw water is collected in the storage tanks. The water is then fed into the
dosing system where anti-scalant is used for softening of water. From the
dosing system, water goes into the sand and carbon filter where
impurities are removed from the water. Carbon filter removes the organic
impurities. Water then goes into the reverse osmosis (R.O.) system which
removes 90-95% of dissolved solids. The finished water is collected into a
stainless steel storage tank. The tank is provided with a manhole for
cleaning purposes. This tank is used for ozonation. Ozone gas is passed for
disinfection. Water from this tank is used in filling machines to fill the
bottles. Empty bottles are fed from one end of the machine. The
automatic filling machine washes the empty bottles, fills them with water
and seals them with the cap. These bottles are then examined against light
to check any defect/leakage. Labels are attached to the bottles as they
pass on the conveyor belt. As the bottles move on the conveyor belt, a
laser printer prints the batch number on every bottle. The conveyor belt
passes through a heated chamber which causes the thin plastic label to
shrink and stick to the bottle. Once the bottle reaches the end of the belt,
it is picked up and packed in cartons. The cartons are then taped and are
ready to be sold.

17. Empty jar Washing Filling
Visual
examinat
ion
Seal Transported
3.A separate jar filling section
deals with the 20 litre jars.
Finished water from the stainless
steel tank is used here. The empty
jars are washed from the inside
and outside. They are filled with
water and the examined for any
leakage. A seal is put on the
mouth of the jar and the jar is
ready for transport.

18. Pre-form Few pre-forms become defective when hot air is not blown properly
Pre-form Blowing machine Pre-form expands into bottle like this

19. Automatic Filling Machine Washing of bottles Filling & Capping
Filled bottles on ConveyorBelt Bottle Labels Workers attaching labels
Caps Bottle stuck in the machine Leaked/Defective Bottles

20. Heat Chamber to shrink label
Batch Number on bottle neck
Laser Printer
Assembling raw cartons with tapes Bottles being packed Final Stock
Empty jars Jar Filling Sealed jars ready
for transport

21. Quality Evaluation :
Safe Water/
Wholesome
Water
Chemically safe
Aesthetically acceptable
Radioactive elements
absent
Organic
Substances absent
Free from bacteria

22. Parameters of water analysis

23. Physical and Chemical Analysis of Water :
Constituents responsible for rendering water unfit for use includes clay, silt, humus, and
color (aesthetically not acceptable and palatability decreases); pH (health-related problems);
hardness (affect mucous membrane), TDS, Ca, Mg, and SO4 (gastrointestinal irritation);
fluoride (dental and skeletal fluorosis); nitrate, Ca, Mg, and Cl (methemoglobinemia and
encrustation in water supply).
Procedure: The physical measurement of water includes pH, specific gravity,
specific conductance, acidity, alkalinity, hardness of water, nitrogen in water, total
solids, and turbidity of water.
(a) pH: The pH is measured accurately using digital pH meter. The pH of pure
water is between 4 and 9.

24. (b) Specific gravity: Specific gravity bottle is used for the
determination.
1. Firstly, the bottle is filled up to the rim in a way so that when cap
is placed excess fluid is removed. This does not allow air bubble
entrapment. Note the weight.
2. Repeat the step with water to be tested and record the weight
again. Apply the formula :
Specific gravity of water from unknown source = weight of sample /
(weight of standard )×( specific gravity of water)
The specific gravity may increase in case of contaminated water due
to high ionic content

25. c) Specific conductance:
The specific conductance is measured accurately using digital
conductivity meter. The conductance may increase in case of
contaminated water due to high ionic content.
(d) Acidity:
It is measured titrimetrically using 0.1 N NaOH solution as titrant
and phenolphthalein as indicator. Briefly, take 10 ml of sample water
in conical flask. Add phenolphthalein and perform titration until pink
color persists. Calculate the amount of NaOH used and compare it
with standard water.

26. (e) Alkalinity: It is measured in the same way as acidity except 0.1 N HCl is used as titrant
and methyl red/methyl orange as indicator.
Procedure :
1. Select the titrant.
2. Select the normality.
3. Adjust the speed of the drops from the burette.
4. Select the titrate and choose a definite volume of the water sample.
5. Select the indicator, phenolphthalein, to get a pink color.
6. Stop titration when the solution becomes colorless, and calculate phenolphthalein
alkalinity (PA) as CaCO3 (mg/L) using the equation . Let A be the volume of titrant (mL)
used in the titration (V1).
7. Add methyl orange to the same flask and continue titration till the color changes from
yellow to orange. The total volume of titrant corresponds to total alkalinity (TA) as
CaCO3 (mg/L). Let B be the total volume of titrant (mL) consumed with both the
indicators (V2)
8. Volume of HCl corresponding to phenolphthalein end point (A) = ..................mL.
Normality of acid = ..................N. Volume of the water sample = ..................mL.
Normality of water corresponding to phenolphthalein end point = ..................ppm.
Volume of HCl corresponding to methyl orange end point (B) = ..................mL.
Normality of acid =..................N. Volume of the water sample =..................mL.
Normality of water corresponding to methyl orange end point =..................ppm
Results: Alkalinity is due to............ =..............ppm

27. (f) Hardness of water
1. Select the titrant.
2. Adjust the speed of the drops from the burette.
3. Adjust the molarity of titrant.
4. Select a definite volume of water sample.
5. Choose the indicator and start the titration.
6. When color changes from wine red to blue, click the “stop” button
and note the volume of EDTA used.
7. Then calculate the hardness of water sample in ppm using the
equation as follows
Total hardness as CaCO3 (ppm)
= Volume of EDTA × .01 × molarity of EDTA × 10*6
/Volume of the sample
Volume of EDTA used = ..................mL.
Molarity of EDTA = ..................M.
Volume of the water sample = ..................mL.
Therefore the total hardness of the sample is =.................ppm.
Result: Total hardness of the water sample ¼ ..................pp

28. (g) Total dissolved solids: It is the portion of solids which pass through the 2.0 μm pore
size filter or smaller. The determination involves two basic methods: Evaporation at
180 ± 2 °C, at this temperature all the mechanically occluded water is lost.
Conductivity determination using digital conductivity meter.
(h) Turbidity of water Turbidity in water is caused by suspended matter such as clay,
silt, finely divided organic and inorganic matter, soluble colored organic compounds,
plankton, and other microscopic organisms. Turbidity is an expression of the optical
property that causes light to be scattered and absorbed. Turbidity measurement by
nephelometer is written in terms of nephelometric turbidity units (NTU). Formazin
polymer is used as the reference turbidity standard suspension.
Principle: Nephelometric method of turbidity measurement is based on a comparison
of the intensity of light scattered by the sample under defined conditions with the
intensity of light scattered by a standard reference suspension under the same
conditions. The higher the intensity of scattered light, the higher the turbidity
Precautions: (a) Meter is designed to prohibit stray light reaching to detector. (b) Short
warm period is necessary to make the instrument free from significant drift. (c) Clear
colorless glass tube is used for sample

29. (i) Determination of chemical oxygen demand (COD) of water sample
1. Select the water sample.
2. To reflux the contents in the RB flask, click the “switch on mantle” button.
3. Click “start titration” to titrate the contents.
4. Select the normality of ferrous ammonium sulfate (FAS).
5. Start titration and note the volume of titrant consumed when color changes from
bluish green to wine red. (Let the volume of titrant be V2 mL.) 6. Repeat the same with
the blank (let the volume of the titrant be V1 mL).
7. COD calculated using the equation
Volume of FAS used = (V1–V2) = ..................mL.
Normality of FAS ..................N.
Volume of the water sample = ..................mL.
Therefore COD of the water sample =..............ppm.
Result: COD of water sample ¼ ....................ppm.
Precautions: 1. Always wear lab coat and gloves in the lab. 2. Clean all the apparatus
with chromic acid and distilled water and ensure that all the glasswares are free from
water droplets while performing the experiment.

30. Bacteriological Analysis of Water :
Determination of the type of bacteria in water is more important than detecting its
number. The three main contaminants mostly contributed by intestinal discharge are
E. coli, Streptococcus faecalis, and Clostridium spp. E. coli being excreted in largest
amount (200–400 billion per day) is of prime concern. The closely related forms are
called as “coliforms.” The main method used for determination is called as “multiple
tube fermentation test.” Coliforms are aerobic or facultative anaerobic, gram-negative,
rod-shaped, non-endospore-forming bacteria. It can ferment lactose in medium to
produce acid and gas just in 24 h at 37 °C. The test is performed in three stages in
sequence: presumptive, confirmed, and completed

31. Bacteriological analysis of water is performed to check the number of bacteria the water is
contaminated with or simply it is a basic test for knowing about the water quality. The complete analysis
consists of series of test to identify the bacteria. It mainly consists of three test presumptive test,
confirmed test and completed test. So, the basic objective of this test is identification of various bacteria
present in a water sample.
REQUIREMENTS
Apparatus: Durham tubes containing lactose broth triple strength with Bromo thymol blue-3 no’s
Durham tubes containing lactose broth regular strength with Bromo thymol blue-6 no’s
Collection bottles with sterile water
Sterile pipette – 10 ml and 1 ml
PROCEDURE:
Presumptive test
Take 50 ml of the water sample and shake it well. Then transfer 10 ml of this sample to each of the
triple strength lactose tubes. After mixing well, transfer 1 ml of this sample to regular strength lactose
tube. Then place it in incubator at 37 C for 24 hours.
Confirmed test
Examine the tubes from presumptive test for acid/gas production. If no gas is produced then it is
negative presumptive test. If any gas/acid is produced compare it with MPN (most probable
number).Tubes showing more than 10% gas is taken for completed test. Take one loopful of this positive
presumptive test sample and streak it on EMB plate. Then incubate this at 37°C for 24 hrs. For better
result, the positive presumptive ones can be collected and one ml of each can be inoculated to Brilliant
Green lactose bile Broth (BGLB) tube, after incubating at 45°C for 24 hrs; then the tubes containing both
gas and turbidity were to be considered positive for faecal coilforms.

32. Completed test :
This test is for confirmation of
coliform bacteria. The plates are
observed for well formed coliform
colonies, by seeing any colonies of
blue black with metallic green sheen
on the plates. Then these colonies
are inoculated in NA slant and
lactose fermentation tube and
incubated at 37°C. Then the colonies
from lactose broth are checked for
gas production and colonies from
NA slant is taken for gram staining.
CONCLUSION
These three steps give a complete
detail about the number of different
bacteria present in water sample
• Recommended who standard limits for
Drinking Water

33. It is water that is taken directly from its source without
treatment. It contains one or more of the following significant
contaminants in the form of dissolved ions, particles and
living organisms:
Humic acid and other complex acids resulting from plant
decay
Minerals, which make water hard
Particles of clay and silt
Microorganisms such as bacteria, viruses, protozoa and their
cysts
Dissolved air molecules, especially oxygen
Salt, which makes water brackish
Industrial or municipal waste
Raw water is purified for a variety of purposes, meeting the
requirements of medical/pharmacological, and
chemical/industrial applications.
Purification methods include:
Physical processes like filtration, sedimentation and
distillation
Biological processes like slow sand filters or biologically active
carbon.
Chemical processes like flocculation and chlorination
Electromagnetic radiation such as ultraviolet light.
For steam generation, suspended solids are
eliminated by settling or filtration. Scale-forming
hardness is reduced by chemical treatment to make
insoluble precipitates that are removable by filtration,
or soluble compounds that do not form scale.
Complete purification is obtained by de-mineralizing
treatments or evaporation.
Industrial raw water purification is employed to
optimize most water-based industrial processes like
heating/cooling/processing, and cleaning/rinsing. The
ultimate goal is to reduce operating costs and risks.
Improper water treatment can cause serious damage to
the process and the final results. Surfaces of pipes and
vessels can be affected by corrosion and steam boilers
can scale or corrode.
Raw water :

34. It is the name given for water which is not considered drinkable (not
drinking water) and is basically used in relation to industrial plants,
industrial processes and production facilities. Process water was
originally subjected to a substantial water treatment, like for instance;
multimedia filters, softeners, reverse osmosis, etc. Process Water in the
industrial water treatment process. Most probably each and every
product being manufactured uses industrial water treatment during
some if not all stages of the production procedure. Industrial water
treatment main purpose is to facilitate the manufacturing process,
reduce cost and help support production for certain products of which
water is an essential element in its composition; i.e: beverages
processing, detergents, paper, chemical processing, etc. The use of
process water can be in many forms such as; Â fabrication, dilution,
sanitation or incorporation of process water into a product. It should
typically have conductivity 0.1 to 50 Microsiemens per Centimeter
µS/cm, with almost zero hardness to prevent scaling. Carbon dioxide
(CO2) and Oxides (Oxygen) cause corrosion. Water requirements
Process water

35. METHODS OF WATER TREATMENT
Water treatment means the cleansing of water through various phases to be
available for end-use by the people. The treated water is then used for various
purposes like irrigation, industrial water supply, drinking, river flow maintenance,
or any other such uses. The treatment of water removes harmful contaminants
and compounds or the concentration of these is reduced for public use. This
treatment is mandatory to promote human health and its uses for drinking and
irrigation.
The water contaminated with feces of humans and animals pose a great threat to
the public because of the presence of microbial elements in them that cause
various diseases. Feces are the main source of viruses, pathogenic bacteria,
protozoa, and helminthes. The destruction or removal of such substances from
the water is essential for it to be used by humans. Reactive chemical agents like
suspended solids are used in the process of purification of water. These agents
help in removing bacteria, viruses, algae, fungi, iron, and manganese.
Water is naturally a pure substance containing hydrogen and oxygen. However,
the distribution and supply of water come in contact with various organic
minerals, man made pollutants, and chemicals. This makes water unfavorable for
drinking purposes as it contains deadly viruses, bacteria, and other dangerous
agents.

36. 1. Screening
Screens are used to protect treatment plant units to help in the efficiency of operations.
Screens remove large floating or suspended solids in the process of inflow. Materials
like leaves, paper, twigs, and other debris are removed so as to avoid equipment or
plant damage. There are two types of screens.
Coarse screens: These are large and heavy screens used to minimize large materials like
fish and logs from entering the water treatment plant. They help in the proper
functioning of the mechanical equipment.
Fine screens: These are used to avoid blockage in the pipes at the treatment plant.
Solids that are caught in the pipes are removed by jet water and are taken for disposal.
2. Aeration
Aeration takes place after the screening process. Water becomes aerated after it has
been exposed in order to take in oxygen from the air. Harmful soluble gases like CO2,
hydrogen sulfide are expelled by aeration.

37. 3.Chemical Addition :
Chemical addition is the process in which a chemical is added that reacts along
with the natural alkalinity to form an insoluble precipitate. The chemicals help
make the suspended particles floating in the water clump together to form a
gelatinous particle called a floc, which is usually larger and heavier than a single
particulate. There is a variety of different chemicals that can be used in this
process. These chemicals are called coagulants. Probably the most popular
chemical used is aluminum sulfate or alum. A few other coagulants are ferrous
sulfate, sodium aluminate, ferric chloride, and manufactured chemicals, which are
compounds called polymers. The polymers are classified as cationic polymers,
anionic polymers, and nonionic polymers. No matter which coagulant or
combination of coagulants are used, they must be mixed extremely well with the
water to form a heavier floc.
4.Coagulation and Flocculation:
Coagulation and flocculation is where chemicals with a positive charge are added
to the water. These chemicals neutralize the negative charge of dirt and other
dissolved particles in the water. Particles bind with these chemicals, forming floc,
similar to the process in the chemical addition step. The treatment unit where
coagulation and flocculation are performed is called the “flocculator.”

38. 5.Sedimentation and Clarification :
After the flocculation process is complete, the water will then head over to the center
of the clarifier or sedimentation basin for sedimentation and clarification. The water
will make its way from the center of the clarifier to the saw tooth weir at the
perimeter of the unit. The large floc of particles are allowed to settle out to the
bottom of the clarifier. A rake is continuously traveling across the bottom of the
clarifier to scrape the floc to the middle of the unit. To pull the settled sludge out of
the clarifier and send it into a sedimentation or disposal pond, pumps are used. With
this process, the majority of suspended material can be removed prior to clarification.
This avoids overloading the filters and allowing more water to be filtered before the
filters are required to be backwashed.
6. Filtration
During the filtration process, clarified water enters the filters from above then is
collected in a drain system at the bottom of the filter unit. Filters are made up
different materials or media, such as sand or gravel. Granular activated carbon is
becoming the media of choice in many conventional plants because it provides
mechanical filtration of particulate matter and it removes organic compounds which
are often associated with taste and odor problems.

39. 7. Disinfection
After the filtration process, the water is clear and as clean as it can get but
there may still be bacteria and viruses present. To destroy the viruses and
bacteria, the disinfection process begins. In the United States, chlorination is
commonly used for disinfection. Chlorine gas, chlorine dioxide, and
hypochlorite are just a few of the different forms that chlorine comes in.
Chlorine is added to the water in an amount that will ensure all microorganisms
are destroyed. Chlorine levels are continuously and very carefully monitored by
the water plants because enough chlorine must be added to ensure the water is
disinfected but also to avoid excess that can cause taste and odor problems
when delivered to the customer
8.Oxidation
Inorganic contaminants like iron, manganese are removed by the process of
chemical oxidation and it further aids in the removal of coagulated particles to
destroy odor-causing and taste compounds. It is often used before coagulation,
adsorption, and sedimentation for efficient removal of particulates, inorganics,
taste, or odor. Oxidants are injected in the form of liquid or gas.

40. 9.Adsorption
The adsorption process removes both organic and inorganic contaminants from
water. Adsorption forms on the surface by the accumulation of a solid called
adsorbents. They include stationary media like metal oxide, ion exchange, and
activated carbon. Flocculation forms floc that can adsorb both inorganic and
organic carbon like arsenic. Activated carbon helps in removing hundreds of
organic contaminants.
10. Fluoridation
Fluoridation is used mainly in communities as it treats water supplies to bring a
balance in the concentrated free fluoride ions. This is done till an optimal level is
reached which helps avoid dental cavities.

41. •References:
•https://www.indiawaterportal.org/articles/indian-standard-drinking-water-bis-specifications-
10500-1991
•https://pureaqua.com/bottled-water-treatment-water-treatment-for-bottling/
•https://geology.com/articles/bottled-water.shtml
•https://www.eskawater.com/natural-spring-mineral-and-purified-water-all-the-differences-
eska-blog/
•https://www.corrosionpedia.com/definition/959/raw-
water#:~:text=Raw%20water%20is%20natural%20water,water%2C%20but%20carries%20more
%20risk
•https://www.copperh2o.com/blogs/blog/the-raw-water-movement
•http://www.bqua.com/what-is-process-water-definition/
•https://fluidhandlingpro.com/water-processing/
•https://sciencing.com/about-5449212-salmon-fish-farming.html
•https://www.commercialfiltrationsupply.com/education/filtration-process-in-
municipal-water-treatment-plants.html
•https://testbook.com/learn/environmental-engineering-water-treatment/
•https://www.slideshare.net/indiawaterportal/indian-standard-for-drinking-water-
as-per-bis-specifications-is-10500-2012-a-presentation-by-arghyam-23rd-feb
•Springer protocol haanbook Basic Techniques in Biochemistry, Microbiology and
Molecular Biology Principles and Technique