Contamination of Drinking Water& Their Remedies

PCSIR, Labs Lahore

Objective

Provide an overview of the types of

chemical and microbial contamination of drinking water and their remedies

World Water Resources

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.

Sources of water

Surface Waters 1. Rain Water

2. River Water

3. Lake Water

4. Sea water

Underground Water 1. Spring

2. Well water

World water Resources

Over the last century

Human population has

increased 3 timesGlobal water

withdrawalhas increased 7

times

World water utilization

22%

8%

70%

0

10

20

30

40

50

60

70

80

Agriculture Domestic Industry

Water uses

% o

f to

tal

wat

er u

sed

Sources of drinking water in Pakistan

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)

Uses of water resources in Pakistan

Agriculture 93% Industry 5%Domestic 2%

Human Water Need

A person needs about 1 gallon water for hydration Usage in Pakistan / person/day 6.0 gallon

Water for Life 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.

Health impact scenario

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)

Health impact scenario

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%

WATER QUALITY PARAMETERS

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

Safe drinking water

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

Colour, taste & Odor

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.

Colour/odour

Pure water---colourless Iron salts ---afetr oxidation ---ferric

hydrooxide—red brown colourOff flavour/off ordour -----

decomposition of organic matter by non pathogenic bacteria

Sulphate --- sulphide by the action of reducing bacteria

Wells---proteolytic organisms

Turbidity, pH

Turbidity is caused by suspended matter

High level turbidity shield and protect

bacteria from the action of disinfecting

agents

Desirable pH limit 6.5-8.5

Beyond this limit the water will affect the

mucous membrane and water supply

system

Substances that change pH of water

Acidic Industries

Sugar - 5 –

6

Distillery 3 -

4

Electro-Plating

unit

2.5-4

Pickle 2 -

3

Basic Industries

Paper 8 –

10 Textile 8.5-

11 Fertiliser

6.5- 9 Oil Refineries

6.5-9.5

HARDNESS

Capacity of water for reducing and

destroying the lather of soap

It is total concentration of calcium and

magnesium ions

Temporary hardness – Bicarbonates of

Calcium and Magnesium

Permanent hardness – Sulphates, chlorides

and nitrates of calcium and magnesium

Surface water is softer than ground water

Causes encrustations in water supply

structures

ALKALINITY

Capacity to neutralize acidPresence of carbonates, bi-carbonates

and hydroxide compounds of Ca, Mg, Na and K

Alkalinity = hardness, Ca and Mg saltsAlkalinity > hardness - presence of basic

salts, Na, K along with Ca and Mg Alkalinity < hardness – neutral salts of

Ca & Mg present

IRON

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

Acceptable limit – 0.3 mg / l

CHLORIDE

Dissolution of salt depositDischarge of effluentsIntrusion of sea waterNot harmful to human beingsRegarding irrigation – most

troublesome anionAcceptable limit - 250 mg/l

NITRATE

Increasing level of nitrate is due to

Agricultural fertilizers, manure,animal dung, nitrogenous material ,sewage pollution

(blue baby diseases to infants)

Maximum permissible limit 45 mg / l

FLOURIDE

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

Heavy Metals

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

Toxicity of heavy metals

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

chromium

Pesticides

Insecticides – kill insects Herbicides – kill weeds Fungicides – suppress or kill fungi

Effects CancerBirth defectsBlood disorderNervous disorderGenetic damage

All Microbes Live in an Aqueous Environment

A

Water Systems

Types of water systems that serve asbreeding grounds for potentially pathogenic species:

Surface Water Ground Water Pipes and storage tanks

Bacterial Water Quality in Pakistan

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

pathogens

E.coliSalmonella typhimouriumLegionella neumpphiliPseudomonosShigellaVibrio cholera

WATER BORN VIRAL DISEASES

WATER BORN VIRAL DISEASES

VIRUS DISEASE

HEPATITIS- A VIRAL HEPATITIS

ROTA VIRUSINFANTILE DIARRHEA

POLIO VIRUS POLIO

Water Borne Diseases/Pathogens

Protozoa Entamoeba histolytica - amoebic

dysentery Giardia lamblia - intestinal disease Cryptosporidium - intestinal disease

Purification on Large scale

When sources of water are Rivers,Streams,Lakes etc. then water is Purified by

Storage Sedimentation Filtration (rapid sand & slow sand) Disinfection (chlorination)

Purification on Medium Scale

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 )

Purification on Small Scale(Domestic Methods)

BOILING: for 5-10 minutes kills almost all organisms &

removes temporary Hardness Bleaching Powder: 5% solution is used Dose: 3-6 drops/L

contact time of ½ hour. Chlorine Tablets/Halazone Tablets. one tablet/litre. Iodine Solution: 02 drops of 2% Soln./litre KMnO4: an amount that gives just pink coloration to the

Water. Alum: used for turbid water in a dose of 0.1-0.4 grains/5

litres of Water.

Purification of water in Emergency/EpidemicBoiling: 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.

DISINFECTION OF WATERCHEMICAL 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

Properties of Chlorine

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/Disadvantages

Advantages

Effective and Economical

Stable and does not deteriorate on storage

No impurities such as salts are introduced.

Can be used at high as well as low temp.

Disadvantage

THM(Trihalomethanes) are carcinogenic

Choroamine disinfection reduce THMs production

due to preferential reaction of chlorine with

ammonia

Sr. #

Parameter (A.P.H.A., 2005)

PS:4639-2004(R)

WHO Limits 2008

1 pH at 25oC 6.5 – 8.5 6.5 – 8.5

2 Total Alkalinity as CaCO3 (meq/L) --- ----

3 Carbonates (mg/L)

4 Bicarbonates (mg/L)

5 Total Hardness as CaCO3 (mg/L)

250 500

6 Calcium Hardness as CaCO3

(mg/L)--- ---

7 Magnesium Hardness as CaCO3 (mg/L)

---

8 Total suspended solids (mg/L)

Nil Nil

9 Total dissolved solids (mg/L)

500 1000

10 Calcium as Ca2+ (mg/L) 100 ----

11 Magnesium as Mg2+ (mg/L) 50

Sr. #

Parameter (A.P.H.A., 2005)

PS:4639-2004(R)

WHO Limits 2008

12 Potassium as K+ 10 ----

13 Sodium as Na+ 50 200

14 Chloride as Cl- 250 250

15 Sulphate as SO42- 250 250

16 Conductivity at 25oC (µS/cm)

--- ---

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

21 Iron (mg/L) 0.3 0.3

22 Manganese (mg/L) 0.05 0.1

23 Zinc (mg/L) 3.0 3.0

Typical Water Quality Standards

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

Analytical services at PCSIR

Microbiology

Heavy Metals

Physical Testing

Pesticide residue

SCOPE OF MICROBIOLOGY TESTING LAB. AT LLC

Water/Drinks testing (APHA)

Enumeration of Heterotrophic Plate

CountEnumeration of Total Coliforms

Enumeration of Fecal coliforms

Enumeration of E.coli

Enumeration of Pseudomonas spp.

INSTRUMENTS

Ion Chromatogram

HPLC

ELISA

PCR

Atomic absorption

GC

ICP

Spectrophotometer

Flame photometer

LCMS

Water purification sachet

What Can We Do?

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.

Reducing Water Pollution 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

Key actions for effective management strategies

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.