1. IMPURITIES IN WATER GUIDED BY PROF. A.M.MALEK PROF.J.P.MODI
PRESENTED BY:-
NAME EN. NO.
DODIYA KOMAL V
LASHKARI KAJAL A
LIMBANI BHOOMI N
SHAH PARITA V
SOLANKI SHIVANGINI

2. SOURCES OF IMPURITIES IN WATER
SR.NO.
SOURCE
EFFECT 1
Sea water
Salts 2
Precipitation
Glasses particulates, salt nuclei, radioactive fall out 3
Surface runoff
Particulates, organic matter, nitrates, phosphates, biocides 4
Ground water
Carbonates, chlorides and sulphates of calcium and manganese; SO2; H2S 5
Lake water
Algae, odour and taste 6
Swamp water
Colour, odour and taste 7
River water
Particulates, organic matter, waste water

3. HYDROLOGICAL CYCLE

4. CLASSIFICATION OF IMPURITIES OF WATER

5. IMPURITIES ARE GROUP UNDER:
PHYSICAL IMPURITIES
CHEMICAL IMPURITIES
BIOLOGICAL IMPURITIES

6. POTABLE WATER
The water fit for drinking purpose or which is not harmful to human health is called POTABLE WATER or WHOLESOME WATER.
PROPERTIES:
Colourless
Odourless
Good taste
Free from harmful M.O.

7. Why We Do Water Quality Testing?
4/28/2017
Why We Do Water Quality Testing?
Ensure safe drinking water
Identify problems
Adopt precautionary measures
Raise awareness
Determine the effectiveness of water treatment technologies
Select an appropriate water source
Influence policies to supply safe water

8. ANALYSIS OF WATER:
There are three parameters of analysing the water quality parameter...
Physical quality parameter
Chemical quality parameter
Biological quality parameter(microscopical characteristics)

9. PHYSICAL QUALITY PARAMETER
TEMPERATURE
COLOUR
TASTE & ODOUR
TURBIDITY
CONDUCTIVITY

10. TEMPERATURE
For drinking purpose temp around 10˚c are highly desirable while temperature above 25˚c are considered objectionable.

11. COLOUR: Disadvantage Pure water –colourless
Following are the source which contribute colour to the water:
Algae metabolism
End product of degraded organic matter
Discharge of partially treated waste water from various industries like food,textile,paper production etc.
Divalent species containing iron and Mg
Disadvantage
Exert toxicity to aquatic life
Coloured water is unsuitable for indurstries
Restrict photosynthetic reaction(reoxygenation decreases)
increase the quantity of chlorine for disinfection of water.

12. TEST
Tintometer
It is measured by comparing water by standard solution of platinum cobalt and standard colour of glass disc.
For drinking purpose colour number of cobalt <20

13. TASTE AND ODOUR Pure water : odourless & good taste
Taste & odour due to:
presence of dissolved gases like H2S, CH4, CO2, O2 etc.
Dissolved organic matter like algae
Mineral salts like NaCl , iron compounds, chemicals, industrial waste
Odour is measured by in terms of threshold number.
The minimum odour that can be detected is called threshold odour number (TON)
TON=vol. of sample in ml + vol. of distilled water
vol. of sample in ml
For public water supplies TON should be grater than 3.
An instrument use for odour test is called osmoscope.

14. WHAT IS TURBIDITY? A measure of water clarity
The murkier the water, the higher the turbidity.
Turbidity reduces the transmission of light into water.
Turbidity increases as a result of suspended solids in the water.

15. TURBIDITY IN THE LAB AND FIELD
Turbidimeter
optical device that measures scattering of light (most accurate)
Measure in NTU (nephelometric turbidity units) or JTU (Jackson turbidity units)

16. CONDUCTIVITY
Conductivity is the measure of water’s ability to conduct an electric current.
Estimates amount of total dissolved minerals (ions).

17. HOW DO WE MEASURE CONDUCTIVITY?
Test with a Conductivity meter
Measured in Siemens or mhos/cm

18. CHEMICAL CHARACTERISTICS
Chemical quality parameters includes:
Total solids
Chlorides
Hardness pH
Alkalinity
Acidity
Nitrogen and its components
Metals and other chemical substances
Dissolved gases

19. TOTAL SOLIDS Total solids =suspended solids + dissolved solids.
Permissible amount of solids in water=500ppm to 1000ppm.
To determine the suspended solids –filtration process with fine filter paper
To determine dissolved solids the filtered sample of water is evaporated and the left is weighted.

20. CHLORIDES In form of CaCl , MgCl , NaCl
Source :marine sedimentation , sea water pollution , industrial and domestic waste
chlorides < 250 mg/l
Determine by:titration
Solution: standard silver nitrate sol
Indicator: potassium chromate

21. HARDNESS Hardness prevents the formation of sufficient foam.
Caused by: Bicarbonate, carbonate, sulphate, chlorides and nitrates of Ca and Mg.
Hardness: 1. Permanent and 2. Temporary
Determination of P.H= Titration (Sol: EDTA Indicator: Chrome Black T
Permissible limit: 75 to 115 ppm

22. pH
pH is value of water indicates the logarithm of reciprocal of hydrogen ion concentration present in water.
Acidic water= 0 to 7
Alkaline water= 7 to 14
Pure water= 7
Portable water= 6.5 to 7.5
It is important in biological treatment.

23. ALKANITITY
The capacity of water accept H+ is called alkalinity
Caused by: Carbonate, bicarbonate and hydroxide of sodium, calcium and magnesium.
Expressed in terms of mg/l of calcium carbonate.
Determine by: Titration
Solution: Sulphuric Acid
Indicator: Methyl Orange
It cause bitter taste and incrustation in pipes.

24. ACIDITY The capacity of water to accept OH- is called acidity.
Caused by: carbon dioxide, sulphate of iron and aluminium.
Determination: Titration
Solution: Sodium Hydroxide
Indicator: Phenolphthalein or Methyl Orange
Expressed by mg/l of calcium carbonate

25. NITROGEN AND ITS COMPONENTS
Free ammonia: 0.5 mg/l
Measured by boiling water and liberated ammonia gas by distillation process
Organic nitrogen: 0.3 mg/l
Measured by adding strong alkaline solution of KMNO4 to already boiled water
Nitrites: nil (very dangerous)
Nitrates: 45 mg/l ( represents fully oxidized organic matter)
If concentration of it is very high, then cause disease of blue baby.

26. TESTING NITRITE, NITRATE AND CHLORINE

27. METAL & OTHER CHEMICAL SUBSTANCES
Iron
Manganese
fluoride

28. IRON Need small amounts of iron in food to be healthy
WHO Guideline value > 0.3 mg/L of iron
Causes a bad taste
Stains water pipes and well aprons
Stains clothes during washing

29. MANGANESE Naturally found in groundwater
Water has a black colour or black flakes
Need some manganese in food to be healthy
Too much or too little manganese can make people sick
WHO Guideline value < 0.4 mg/L> 0.15 mg/L of manganese
Causes a bad taste
Stains water pipes and creates a coating that comes off as small black flakes
Stains clothes during washing
Stains food during cooking

30. FLUORIDE
Naturally occurring in groundwater

31. FLUORIDE AND HEALTH
Helps make teeth strong and prevents decay at low doses (0.5 – 1.0 mg/L)
Higher doses are not good for teeth (1.5 – 4.0 mg/L)
Very high doses harms the skeleton (> 10 mg/L)
WHO Guideline < 1.5 mg/L

32. MICROBIOLOGICAL TESTING METHODS
3 methods to determine presence of bacteria in water:
Presence-Absence (P-A)
Most Probable Number (MPN)
Membrane Filtration

33. PRESENCE-ABSENCE (P-A)
Simplest method
Add water sample to a bottle containing broth and let it sit for hours
Color will change if indicator organism is present
Does not show numbers of bacteria

34. Positive for Coliforms
PRESENCE-ABSENCE
Positive for Coliforms
Positive for E. coli
Negative

35. MOST PROBABLE NUMBER (MPN)
Tells the number of bacteria that are most likely to be in the water sample.
Add water sample or diluted sample to 5 or 10 or test tubes.
Incubate for hours.
Gas production and/or cloudiness will be visible if the indicator organism is present.
Typically used for wastewater or turbid samples.

36. MOST PROBABLE NUMBER

37. MOST PROBABLE NUMBER (MPN)

38. MOST PROBABLE NUMBER (MPN)
Advantages
Quantitative results
Simple to understand and use
Relatively inexpensive
Can be used with turbid water
Limitations
More labor-intensive than P-A
Requires some training
Requires incubator & other equipment

39. MEMBRANE FILTRATION Most accurate method to count bacteria
Filter 100 ml of a water sample
Add broth to a Petri dish which provides nutrients for the indicator organism to grow
Filter the water using the filtration equipment
Transfer the filter paper to the Petri dish
Incubate for hours depending on the broth
If the indicator organism is present, colonies will appear on the filter paper and can be counted
Results are reported as the number of colonies per 100 mL of water sample.

40. MEMBRANE FILTRATION

41. MEMBRANE FILTRATION Advantages: Able to count the number of bacteria
Most accurate test method
Ability to test many samples at once
Internationally recognized method
Rapid
Easy & Economical.
Gives direct result.
Useful in rural areas.
Samples can be tested in the field

42. MEMBRANE FILTRATION Limitations: More labour intensive than MPN, P-A
Requires more training
Requires additional equipment
Toxic substances in the water may be absorbed by filter and interferes with bacterial growth.

43. Thank you