PCSIR, Labs Lahore
Provide an overview of the types of
chemical and microbial contamination of
drinking water and their remedies
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Over two thirds of the earth's surface is
covered with water
97.2% of which is contained in the five
oceans.
only less than 2.7% of global water is
freshwater.
Only less than 0.7% is available for
human use.
Surface Waters
1. Rain Water
2. River Water
3. Lake Water
4. Sea water
Underground Water
1. Spring
2. Well water
Over the last century
Human population has
increased 3 times
Global water withdrawal
has increased 7 times
% of total water used
80
70
70%
60
50
40
30
22%
20
8%
10
0
Agriculture
Domestic
Water uses
Industry
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Glacieres--- hamalayan Mountains
(Chenab,Indus, Jehlum)
Drinking water to Urban areas (Tehsil &
District managemnt bodies—WASA & PHED)
Ruler areas ---river, canal, sub soil,pond,
rainwater)
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Agriculture 93%
Industry 5%
Domestic 2%
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A person needs about 1 gallon
water for hydration
Usage in Pakistan / person/day
6.0 gallon
Over 1.1 billion people lack access to safe water
supply, while 2.6 billion people lack adequate
sanitation.
 Water associated to infectious disease claim upto
3.2 million lives each year, approx. 6% all deaths
globally.
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 Rs. 14 billion is spent on
the water borne disease
(world Bank)
 33 % death are due to typhoid, cholera, Diarrhea,
dysentery, and hepatitis (UNICEF)
 Pakistan rank 2nd among 31 countries in annual
diarrhea episode o f children (WHO)
 80% of all illness in
developing countries
is caused by water
related diseases.
 90% of wastewater in
developing countries
is discharged directly
into rivers and streams
without treatment.
 Poor health status of
Pakistan----infant
mortality rate 12.6%
Physical.
 Suspended solid (SS), color, taste, smell,
temp.
Chemical.
 Dissolved substances, alkalinity, hardness,
fluoride, heavy metal, organic compound,
nutrient (nitrogen & phosphorus), pH,
biochemical oxygen demand (BOD), chemical
oxygen demand (COD).
Biology.
 Bacteria, virus, protozoa, helminthes
There is no pure water in nature, as it can contain up to 90
possible unacceptable contaminants
 Free from pathogenic organisms
 Clear
 Not saline
 Free from offensive taste or smell
 Free from compounds that may have adverse effect on
human health
 Free from chemicals that cause corrosion of water supply
systems
Color may be due to the Presence of organic matter,
metals (iron, manganese) or highly colored industrial
waste
 Desirable that drinking water be colorless
 Taste & odor are mainly due to organic substances,
,Biological activity, industrial pollution
 Taste buds in the oral cavity specially detect inorganic
compounds of metals like magnesium, calcium, sodium,
copper, iron and zinc
 Water should be free from objectionable taste and odour.
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Pure water---colourless
Iron salts ---afetr oxidation ---ferric
hydrooxide—red brown colour
Off flavour/off ordour -----decomposition of
organic matter by non pathogenic bacteria
Sulphate --- sulphide by the action of
reducing bacteria
Wells---proteolytic organisms
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Turbidity is caused by suspended matter
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High level turbidity shield and protect bacteria from the
action of disinfecting agents
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Desirable pH limit 6.5-8.5
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Beyond this limit the water will affect the mucous
membrane and water supply system
Acidic Industries
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Sugar -
5–6
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Distillery
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Electro-Plating unit
3- 4
2.5-4
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Pickle
2- 3
Basic Industries
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Paper
8 – 10
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Textile
8.5-11
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Fertiliser 6.5- 9
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Oil Refineries
6.5-9.5
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Capacity of water for reducing and destroying the lather
of soap
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It is total concentration of calcium and magnesium ions
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Temporary hardness – Bicarbonates of Calcium and
Magnesium
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Permanent hardness – Sulphates, chlorides and nitrates of
calcium and magnesium
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Surface water is softer than ground water
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Causes encrustations in water supply structures
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Capacity to neutralize acid
Presence of carbonates, bi-carbonates and
hydroxide compounds of Ca, Mg, Na and K
Alkalinity = hardness, Ca and Mg salts
Alkalinity > hardness - presence of basic salts, Na,
K along with Ca and Mg
Alkalinity < hardness – neutral salts of Ca & Mg
present
 One of the earth’s most plentiful resource
 High iron causes brown or yellow staining of
laundry, household fixtures
 Metallic taste, offensive odour, poor tasting
coffee
 Cause iron bacteria
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Acceptable limit – 0.3 mg / l
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Dissolution of salt deposit
Discharge of effluents
Intrusion of sea water
Not harmful to human beings
Regarding irrigation – most troublesome
anion
 Acceptable limit - 250 mg/l
Increasing level of nitrate is due to
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Agricultural fertilizers, manure,animal dung,
nitrogenous material ,sewage pollution
(blue baby diseases to infants)
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Maximum permissible limit 45 mg / l
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 Occurs naturally
 Long term consumption above permissible level
can cause –
dental flurosis (molting of teeth)
Skeletal flurosis
Acceptable limit – 1 mg / l
 Remedy –
1) Deflouridation
2) Mixing Fluride free wate
3) Intake of vitamin C,D,
calcium,antioxidants
 Non degradable and are toxic to human health
 Common heavy metals are Lead, Mercury,
cadmium, arsenic
 Produced by industrial activities and are slowly
deposited in surrounding water and soil
 Transported by food, water ,air, absorption,
adsorption on materials
Heavy Metals
Health effects
Cadmium
Lung, liver ,kidney damage
Lead
Lung, liver ,kidney damage
Arsenic
Lung, liver ,kidney damage
Mercury (inorganic)
Lung, liver ,kidney damage
Zinc
Skin irritation
Copper
liver ,kidney damage
 Insecticides – kill insects
 Herbicides – kill weeds
 Fungicides – suppress or kill fungi
Effects
 Cancer
 Birth defects
 Blood disorder
 Nervous disorder
 Genetic damage
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A
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Types of water systems that serve as
breeding grounds for potentially
pathogenic species:
Surface Water
Ground Water
Pipes and storage tanks
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Waterborne pathogens are present in large
numbers
Largely due to problems with inadequately
maintained pipes, low pressure, poor hygiene
standards and intermittent delivery, even
municipal well water is unsafe
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E.coli
Salmonella typhimourium
Legionella neumpphili
Pseudomonos
Shigella
Vibrio cholera
WATER BORN VIRAL
DISEASES
VIRUS
HEPATITIS- A
ROTA VIRUS
POLIO VIRUS
DISEASE
VIRAL HEPATITIS
INFANTILE DIARRHEA
POLIO
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Protozoa
 Entamoeba histolytica - amoebic dysentery
 Giardia lamblia - intestinal disease
 Cryptosporidium - intestinal disease
When sources of water are
Rivers,Streams,Lakes etc. then water is
Purified by
 Storage
 Sedimentation
 Filtration (rapid sand & slow sand)
 Disinfection (chlorination)
When sources of water are wells,Springs,Tanks
etc.Then water is purified by the addition of
 Bleaching powder/Chlorinated Lime as it is
Cheep
Easy to use
Reliable and safe
 Water filters( R.O, UV )
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BOILING: for 5-10 minutes kills almost all organisms &
removes temporary Hardness
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Bleaching Powder: 5% solution is used Dose: 3-6 drops/L
contact time of ½ hour.
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Chlorine Tablets/Halazone Tablets. one tablet/litre.
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Iodine Solution: 02 drops of 2% Soln./litre
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KMnO4: an amount that gives just pink coloration to the
Water.
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Alum: used for turbid water in a dose of 0.1-0.4 grains/5
litres of Water.
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Boiling: for 5-10 minutes.
High Test Hypo chlorite: used in granular
form Dose: 01gm./10 litres of water.
Liquid Bleach/5% Sodium Hypo chlorite
solution: Dose: 14 ml./1000 litres of water.
Bleaching Powder: used in a dose of
2.3gm./1000 litres of water.
CHEMICAL METHODS / GERMICIDES
 CHLORINE: is used for purification of water on large scale
 KMnO4: used for disinfection of water in wells especially
during epidemics
 CuSO4/CaCl2: used for the removal of algae
 Lime: used for muddy water
 Ozonization & U.V. irradiation: both methods are used for
disinfection of water in swimming pools
 Silver: sand coated with silver used in slow sand filters
instead of plain sand
 Charcoal: used as adsorbent to remove color,odor & taste
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Killing of pathogenic bacteria by inhibiting their protein
synthesis.
Oxidizes Iron, Manganese & Hydrogen Sulphide.
Destroys taste & odor producing constituents.
It controls algae growth.
It helps in coagulation and suspension of the organic
matter.
Efficiency of chlorine increases, when it combines with
Ammonia
It decreases, when it combines with Sulphides, Ferrous
salts & inert matter in suspension form
Advantages
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Effective and Economical
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Stable and does not deteriorate on storage
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No impurities such as salts are introduced.
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Can be used at high as well as low temp.
Disadvantage
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THM(Trihalomethanes) are carcinogenic
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Choroamine disinfection reduce THMs production due to
preferential reaction of chlorine with ammonia
Sr.
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Parameter (A.P.H.A., 2005) PS:46392004(R)
1
pH at 25oC
2
Total Alkalinity as CaCO3
(meq/L)
3
Carbonates (mg/L)
4
Bicarbonates (mg/L)
5
WHO Limits
2008
6.5 – 8.5
6.5 – 8.5
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Total Hardness as CaCO3
(mg/L)
250
500
6
Calcium Hardness as CaCO3
(mg/L)
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7
Magnesium Hardness as CaCO3
(mg/L)
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8
Total suspended solids (mg/L)
Nil
Nil
9
Total dissolved solids (mg/L)
500
1000
10
Calcium as Ca2+ (mg/L)
100
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11
Magnesium as Mg2+ (mg/L)
50
Sr.
#
Parameter (A.P.H.A.,
2005)
PS:46392004(R)
WHO Limits
2008
12
Potassium as K+
10
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13
Sodium as Na+
50
200
14
Chloride as Cl-
250
250
15
Sulphate as SO42-
250
250
16
Conductivity at 25oC
(µS/cm)
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17
Nitrate as NO3- (mg/L)
10.0
50
18
Nitrite NO2- (mg/L)
1.0
0.5
19
Fluoride F- (mg/L)
0.7
1.5
20
Arsenic (µg/L)
10.0
10.0
 Drinking Water
 No coliforms contamination acceptable
 Recreational water
 200 fecal coliforms /100 ml
 Fish and wildlife habitat
 5000 fecal coliforms/100 ml
 Shellfish
 14 fecal coliforms/100 ml
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Microbiology
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Heavy Metals
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Physical Testing
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Pesticide residue
Water/Drinks testing (APHA)
Enumeration
of Heterotrophic Plate
Count
Enumeration of Total Coliforms
Enumeration
of Fecal coliforms
Enumeration
of E.coli
Enumeration
of Pseudomonas
spp.
 Ion Chromatogram
 HPLC
 ELISA
 PCR
 Atomic absorption
 GC
 ICP
 Spectrophotometer
 Flame photometer
 LCMS
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Fertilize your garden and yard plants with manure
or compost instead of commercial inorganic
fertilizer.
Minimize your use of pesticides.
Never apply fertilizer or pesticides near a body of
water.
Grow or buy organic foods.
Compost your food wastes.
Do not use water fresheners in toilets.
Do not flush unwanted medicines down the toilet.
Do not pour pesticides, paints, solvents, oil,
antifreeze, or other products containing harmful
chemicals down the drain or onto the ground.
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Prevent groundwater contamination
Greatly reduce nonpoint runoff
Reuse treated wastewater for irrigation
Find substitutes for toxic pollutants
Work with nature to treat sewage
Practice four R's of resource use (refuse, reduce,
recycle, reuse)
Reduce resource waste
Reduce air pollution
Reduce poverty
Reduce birth rates
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Establishment ground water regulatory
framework.
Proper disposal& sanitary inspection of waste
water
Mapping of ground water quality
Monitoring of water quality at District level
Up gradation of analytical labs.& equipments
Strengthening of R&D institutions to develop
appropriate water purification techniques.