Analysis of water

1. MICROBIAL AND CHEMICAL
ANALYSIS OF POTABLE WATER IN
PUBLIC – WATER SUPPLY
WITHIN LAGOS UNIVERSITY
Presented by:
Govind Gupta
Kishan Sharma
Navratan Kumawat

2. Introduction
• Water is one of the most important of all natural
resources known on earth. It is important to all living
organisms, most ecological systems, human health, food
production and economic development.
• The safety of drinking water is an on going concern
within the global village. Traditionally, the safety of
potable water supplies has been controlled by
disinfection, usually by chlorination and coliform
population estimates.
• However, it has been reported that coliform-free potable
water may not necessarily be free of pathogens (Sim et
al., 1987).

3. Introduction
• Many congenital diseases such as goiter and cancer have been
associated with presence of high concentration of a chemical
or its inadequate supply in water.
• Opinya et al, (1987) reported that low or high level of fluoride
ions concentration in water as the major cause of dental
flurosis.
• Biofilms in drinking water distribution system has generated
health concerns.
• Biofilms are coating of organic and inorganic materials in pipes
that can harbor, protect and allow the proliferation of several
bacterial pathogens.
• The aim of this study was to evaluate the sanctity of potable
water in circulation within Lagos
• State University, Ojo Campus and suggest safety measures to
reduce the incidence of water – borne diseases.

4. Materials and Methods
• The experiments were carried out at the laboratories of Lagos State
Water Corporation (Iju Water Works) Lagos. The source of water was
the four tap water sources in four Strategic Location within Lagos
State University, Ojo Campus.
• Aseptically, tap water was collected in the morning into sterile 4-litre
plastic container in the morning after the tap was allowed to run for
5 minutes.
• The 4-litre container were immediately covered tightly after
collection of water samples and transported to the laboratory for
chemical and microbiological analysis.
• This process was done separately on each occasion for the four
selected sampling points in the four faculties.
• Nutrient agar, Baired – Parker agar, MacConkey agar, Plate count
agar, Potato dextrose agar (PDA), Pseudomonas agar base were used
for the isolation of micro-organisms.

5. Isolation of micro-organisms
• Membrane filtration technique was used to
isolate the microorganisms present in the water
samples.
• The funnel of the membrane filtration unit has a
capacity of 50ml and the funnel was mounted
one receptacle fixed to the vacuum pump which
allows the water to flow over the porous sterile
membrane filter (0.45μm).
• Aseptically, the membrane filters were placed on
each microbial growth medium using sterile
forceps after passage of 100ml of water sample.

6. Isolation of micro-organisms
• The following media (Baired Parker agar, MacConkey
agar, Plate count agar, potato dextrose agar,
Pseudomonas agar base) were prepared and autoclaved
at 1210C for 15 minutes at 15 psi before being inoculated
with membrane filters.

7. Isolation of Escherichia coli
• Water sample (100ml) was drawn and filtered with sterile
membrane filter 0.45μm
• The filter membrane was then placed on MacConkey agar
aseptically.
• Then the plate was incubated at 450C for 22hrs (APHA 1992;
Balogun, 2000).

8. Isolation of general
coliforms
• Water sample (500ml) was filtered with a separate sterile
membrane filter (0.45μm).
• The membrane filter was then placed aseptically on
MacConkey agar and incubated at 370C for 24hrs (APHA, 1992;
Balogun, 2000).

9. Isolation of total bacteria
• Water sample (100ml) was filtered with a sterile membrane
filter (0.45μm).
• It was then placed aseptically in an empty sterile Petri-dish by
pour-plate method using plate count agar incubated at 370C
for 24hrs (APHA, 1992: Balogun, 2000).

10. Isolation of Pseudomonas
aeruginosa
• Water sample (100ml) was filtered with a sterile membrane
filter (0.45 μm).
• It was then placed aseptically on Pseudomonas agar base and
incubated at 420C for 48hr (APHA, 1992: Balogun 2000).

11. Isolation of yeast and
moulds
• Water sample (100ml) was filtered with a sterile membrane
filter (0.2 μm).
• The membrane filter was then placed aseptically on potato
dextrose agar and incubated at 220C for 48hrs (APHA, 1992:
Balogun, 2000).

12. Isolation of Staphylococcus
aureus
• Water sample (100ml) was filtered with a sterile membrane
filter (0.45 μm).
• It was then placed aseptically on the Baired-parker agar and
then incubated at 370C for 24hrs (APHA,1992: Balogun, 2000).

13. Chemical Analysis
Alkalinity
Water sample(100ml) N/50 HCl(in burette)
↘ ↙
Add drop of Methyl orange indiactor(titrate against HCl)
(Balogun, 2000)

14. Acidity
Water sample(100ml) N/50 NaOH(in burette)
↓ ↙
Add drop of phenolphthalein(titrate against NaOH)
(Balogun, 2000)

15. Hardness
Total Hardness
Water sample(100ml)
↓
Add Buffer solution(pH=9)
↓ N/50 EDTA(In burette)
Add two drop of EBT ↙

16. Calcium hardness
Water sample(100ml)
↓
Add Buffer solution(pH=12 NaOH)
↓ N/50 EDTA(In burette)
Add two drop of murexide ↙
(Balogun, 2000)

17. Magnesium hardness
• Deduced by obtaining the difference between the values of
total hardness and calcium hardness of each water sample
(Balogun, 2000)

18. Spectrometric analysis of water
samples
• The concentration of chloride, iron, sulphate, copper, fluoride
ions were detected using spectro-metric analytic system.
• The TDS meter detected total dissolved solids.
• Turbidity was determine using the turbidity meter
(Balogun, 2000)

19. Results and Discussion
Generally, the chemical quality of the water samples under study falls
within the standards stipulated by World Health Organization and
Federal Environmental Protection Agency.

20. Mean numberof microbialspeciesdetectedin the
water (per100ml) distribution
system

21. Mean value of selected chemical
properties of water in the
distribution

22. Acknowledgement
We are grateful to Omolara Brown of Lagos
State Water Corporation for her assistance.

23. References
• 1. Anonymous (1982). The bacteriological Examination of
drinking water supplies. Department of the Environment,
H. Social Security and P.H.L. Service P71 HMSO.
• 2. APHA (1992) Microbiological Examination of Water In:
Standard methods evaluation of water one wastewater
18th ed. American Public Health Association, Washington,
D.C.
• 3. Bola Balogun (2000) Monitoring and Assessing Drinking
water quality In: Lagos State Water Corporation In- House
Training for Chemist 19th – 21st Dec. 2000 p. 1-32.
• 4. WHO (1989) Water Quality Regulations In: Guidelines fro
drinking water quality World Health Organization, Geneva
Switzerland.

24. Thank You