A presentation on WSSE by the students of group 4 of Dept. of CEE ,SUST

1. INTRODUCTION
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Our course is Water Supply and Sewerage Engineering Sessional. In this course we have worked on
the water and wastewater quality of first ladies hall of Shahjalal University of Science and Technology
,Sylhet.
I don’t need to explain the importance of water in our daily life because It has been said that We can
live without love but not water. As a resident of this hall I think It’s quite important for us to know about
it’s water quality.
Our course has been distributed to two types of water :
 Drinking Water (belongs to Water Supply Engineering)
 Sewage (belongs to Sewerage Engineering)
In Water Supply Engineering to measure the drinking water quality we did the following experiments:

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 Determination of pH.
 Determination of Carbon Dioxide of water.
 Determination of turbidity of water.
 Determination of total alkalinity of water(Titration Method).
 Determination of Iron in water.
 Determination of manganese in water.
 Determination of Hardness of water.
In Sewerage Engineering to measure the sewage quality we did the following experiments:
 Determination of TS,DS and SS.
 Determination of Biochemical Oxygen Demand(BOD) of sewage.
 Determination of Chemical Oxygen Demand(COD) of sewage.
 Determination of chloride.
The details and findings of our experiments are given below.

3.  pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen
ion.Water that has more free hydrogen ions is acidic (pH <7), whereas water that has more free
hydroxyl ions is basic (pH > 7).
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DETERMINATION OF pH
Importance of pH
● determines the solubility (amount that can be dissolved in the water)
● availability of chemical constituents such as nutrients (phosphorus, nitrogen, and carbon)
● availability of heavy metals (lead, copper, cadmium, etc.)
determines their toxicity
● coagulation of water
● disinfection
● water softening
● corrosion control

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From the result of our experiment , we got the pH of our sample 7.5 which is allowable for drinking
water.
 Result
 Conclusion
 Measuring pH
The pH of an aqueous sample is usually measured electrometrically with a glass
electrode such digital pH meter.
Although pH usually has no direct impact on water consumers, it is one of the most important
operational water-quality parameters. Careful attention to pH control is necessary at all stages of
water treatment to ensure satisfactory water clarification and disinfection.
● extreme pH (>10) values results in irritation to the eyes, skin, and hair loss.
● Below pH 4, redness and irritation of the eyes have been reported.
● Water with a pH > 8.5 can cause aesthetic problems.
● Water with a pH level between 6 and 8.5 is safe to drink because it is neither acidic nor
alkaline enough to be dangerous in the human body.
 EFFECTS ON HUMANS

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Determination of Carbon Dioxide of water
Why CO2?
Carbon dioxide dissolves in water to produce carbonic acid .Therefore high concentration are
corrosive and can be harmful to fish & other aquatic life.
What is Corrosion?
Corrosion is the deterioration of a metal as a result of chemical reactions between it and the
surrounding environment.
Causes of Corrosion
 Waste of vulnerable resources
 Reduction in efficiency
 Costly maintenance
 Expensive over design

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Significance
Corrosion is the principal difficulty caused by carbon dioxide gas ionizes on solution in
water producing carbonic acid because of the low pH value & thus cause corrosive
character.
Result and comment
• Methodology:- Titration
• From calculation, we found out the concentration of CO2 in the sample was 6.67 mg/l
• Carbon dioxide is present in all surface water, generally in amount less than 10 mg/l. In
our sample, we found the concentration of CO2 is 6.67 mg/l which is tolerable.

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Determination Of Turbidity of the water
What is Turbidity?
Turbidity is the measure of relative clarity of a liquid. It is an optical characteristic of water and an
expression of amount of light that is scattered by material in water when sunlight shinned through
water sample.
Causes of Turbidity
Turbidity is the water is caused by suspended matters like :-
 clay
 Slit
 Organic matters
 Phytoplankton and other micro-organisms

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Result and comment
• Methodology:- SPECTRONSCOPY
• Device :- UV VISIBLE SPECTROPHOTOMETER ( range 400 – 800nm)
• From calculation, we found out the turbidity of the sample was 21.62 NTU
• The WHO (World Health Organization), establishes that the turbidity of drinking water
shouldn't be more than 5 NTU, and should ideally be below 1NTU. For Bangladesh
maximum limit of turbidity in drinking water is 25NTU. So, we can say that the turbidity
of the sample water was okay.
Significance of Turbidity
As turbidity is affected by total suspended solids and micro-organisms of the water, it
plays an important role in water treatment. Cause we measure total bio-degradable via
dissolved oxygen. And micro-organisms helps this process.

9. Determination of Alkalinity
What is Alkalinity?
Capacity to neutralize acids(mg/L as CaCO3).It is due to the presence of salts of weak
acids.
Why Alkalinity is important?
- to interpret and control of water and WW treatment process.
- to assume the turbidity of drinking water.
- to control corrosion in piping systems.
- to assure palatable taste of water
Forms of Alkalinity: Alkalinity presents in three forms
A. Bicarbonates,( HCO3- -) : pH 4.5 ≤ pH 8.3 (Major constituent)
B. Carbonates, (CO3- -) : >pH 8.3
C. Hydroxide, (OH- - ) : > pH 9
Carbonate alkalinity may be present either with OH- or HCO3- - alkalinity but OH-
and HCO3- - alkalinity don’t exists together.
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10. Which form of Alkalinity is present?
1. Phenolphthalein Alkalinity: measure by the end point of phenolphthalein
indicator.
may present OH- or CO3- - or both.
2.Methyl Orange Alkalinity: measure by the end point of methyl orange indicator.
may present OH-, CO3- -, HCO3- - or CO3- -, HCO3- - combination .
finally we find the specific alkalinity by the five relation of methyl orange and
phenolphthalein alkalinity.
Findings:
Methodology: Volumetric titration
Result : bicarbonate alkalinity , 64.67 mg/l (as CaCO3 )
The permissible value of alkalinity is 80-120 mg/l(as CaCO3 ).So experimented
(1st ladies hall) water is safe ,palatable and less turbid.
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11. Determination of Iron in Water
 Iron is a natural constituent of soil . The important sources of iron are sulfide and
carbonate minerals . It mainly presents in two forms : either the soluble ferrous iron or the
insoluble . Water containing ferrous iron is clear and colorless because the iron
completely dissolves . In natural water , ferric iron is rarely found without being high acidic
because of formation of insoluble ferric oxide.
 The determination of Iron is necessary for the safety of human body . It is considered as
secondary or aesthetic contaminant .But It is essential for good health because Iron helps
to transport oxygen in the blood cell .
 FOR DRINING WATER IRON CONCENTRATION
 WHO ------ 0.3mg/l River -----(.5 – 1)mg/l
 Bangladesh ------ 1mg/l GW -----(.5 – 50)mg/l
 GW contains more Iron than SW because it has to pass through many soil layers.
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Results & Comments
 SAMPLE :- FIRST LADIES HALL OF SUST
 REAGENT :- HCL ,KCNS (Fe3+
𝐻𝐶𝑙
Fe2+)
 Methodology:- SPECTRONSCOPY
 Device :- UV VISIBLE SPECTROPHOTOMETER ( range 400 – 800nm)
From the calculation , the amount of Iron in our sample was .44mg/l ( find from absorption and
concentration data)
Bangladesh recommends the amount of iron is 1mg/l . Our result was satisfied . If we drink this
water , it does not create bitter taste and cause skin disease . No aesthetic and turbidity problem
in our sample. So, it is safe to drink without hesitation.
Limitations
There was some error in our experiment . In the calculation , we used least square method to
get the answer . This error was occurred because of contained water by cuvette . The exact
amount of absorption could not be got appropriately .

13. DETRMINATION OF MANGANESE OF WATER
INTRUDUCTION:
Manganese is a common naturally‐occurring mineral found in rocks, soil, groundwater, and surface
water. It is also an essential trace mineral necessary for proper metabolism, immune system
function, digestion, bone strength, iron and steel production, used as a catalyst, to decolorize glass
and make violet colored glass.
Lack of Manganese: Excess of Manganese:
-Fatness -Schizophrenia
-Glucose intolerance -Dullness
-Blood clotting -Weak muscles
-Skin problems -Headaches
-Lowered cholesterol levels -Insomnia
-Skeleton disorders -Parkinson
-Birth defects
-Changes of hair color
-Neurological symptoms
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14. For Drinking Water: Appr. Daily Requirements:
WHO 0.4 mg/L Man 2.3 mg
Bangladesh 0.1 mg/L Woman 1.8 mg
Result and comment:
 SAMPLE :- FIRST LADIES HALL OF SUST
 REAGENT: Manganese sulfate solution, Dilute Nitric acid, Silver Nitrate solution, Ammonium per sulfate
crystals.
 Methodology: Persulphate method.
 From the calculation, The amount of Mn in our sample was 0.031 mg/l.
 The WHO (World Health Organization), establishes that the Manganese of drinking water should not be
more than 0.4 mg/l. For Bangladesh maximum limit of Manganese in drinking water is 0.1mg/l. so we can
say that our sample is safe to drink and not effected to our health.
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15. DETERMINATION OF HARDNESS OF WATER
What is hardness?
Hardness of water is a measure of the capacity of water to precipitate soap that is mainly done
by calcium and magnesium ions and computed as the sum of calcium and magnesium
concentration both expressed as CaCO3 in mg/l.
SANITARY SIGNIFICANCE:
 Economic loss as soap consumption
 Precipitate adhere to surface of tube, link, dishwashers and may clothing dishes and
other item
 Residue of precipitate may remain in the pores, so the skin may feel rash and
uncomfortable
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16. WATER CLASSIFICATION IN TERM OF HARDNESS:
Soft < 50mg/l as CaCO3
moderately hard. 50-150mg/l as CaCO3
Hard 150-300mg/l as CaCO3
Very hard. >300mg/l as CaCO3
RESULT:
The hardness of our water that was collected from first ladies hall was 80mg/l.
COMMENT:
It was moderately type of hardness. WHO standard hardness is 50 mg/l
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17. Sewerage Engineering
DETERMINATION OF TOTAL SOLIDS, DISSOLVED
SOLIDS AND SUSPENDED SOLIDS
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Now Firstly what do we mean by total solid, dissolved solid and suspended solid?
 Total solids is the term applied to the material residue left in the container after
evaporation of the sample and its subsequent drying in an oven at a defined
temperature.
 The term total dissolved solid refer to material that are completely dissolved in water.
It is defined as residue upon evaporation of filtrate sample.
 And the term total suspended solid can be referred to material which are not dissolved
in water. total suspended solids the portion of total solids retained by a filter.
In our experiment we have used waste water sample of 1st ladies hall. Our short outcome
Is shown below:

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Total solid = 690 mg/l Dissolved solid = 490 mg/l Suspended solid = 200 mg/l
Again according to Michigan Water Quality Standards water with a TSS concentration less than
20 mg/l to be clear. Water with TSS levels between 40 and 80 mg/l tends to appear cloudy,while
water with concentrations over150 mg/l usually appears dirty. But sadly Bangladesh doesn’t
have any standard for TSS.
According to USPHS (United States Public Health Service) water should not contain more than 500mg/l of total
dissolved solids. On theOther hand according to WHO The palatability of drinking water
has been rated by panels of tasters in relation to its TDS level as follows: excellent, less
than 300 mg/litre; good, between 300 and 600 mg/litre; fair, between 600 and 900 mg/litre;
poor, between 900 and 1200 mg/litre; and unacceptable, greater than 1200 mg/litre.
Bangladesh standard for total dissolved solids is 1000mg/l
Conclusion: Though dissolved solid standard for USPHS and WHO exceeded our obtained
value but according to Bangladesh standard our dissolved solid concentration is below 1000 mg/l.
So it can be accepted as Bangladesh is a developing country. But the water is dirty according to
Michigan Water Quality Standards water. So further treatment of wastewater is needed.

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Determination of BIOCHEMICAL OXYGEN DEMAND
(BOD) OF SEWAGE
What is BOD test?
The biochemical oxygen demand determination is a chemical procedure for determining
the amount of dissolved oxygen needed by aerobic organisms to break the organic
matter present in the water sample at certain temperature over a specific period of time.
Environmental Significances
 BOD is the principle test to give an idea of the biodegradability of any sample.
 Important parameter to assess the pollution of surface and ground water.
 Data from BOD test used for the development of engineering criteria for the design of
wastewater treatment plan.

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Limitations
 It measures only biodegradable organic matter.
 Time duration of the test is very long i.e. 5 days.
 Sometimes pre-treatment is needed if sample contains toxic waste.
Results & Comments
 Result : BOD of our sample was 72 mg/l.
 According to standard, the BOD range between 1~5 mg/l is moderate , 6~100 is poor &
above 100 is very poor. We found from our sample contains organic waste which is under
poor condition.

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DETERMINATION OF CHEMICAL OXYGEN
DEMAND (COD)
 WHAT IS COD?
 COD or Chemical Oxygen Demand is the total measurement of
all chemicals in the water that can be oxidized.
WHAT IS THE SIGNIFICANCE?
It is an important water quality parameter to assess the effect of
discharged wastewater on the receiving environment which is
similar as BOD.
ADVANTAGES:
1. COD results are available much sooner than BOD.
2. Takes fewer manipulations of the sample.

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But,
there are some disadvantages as well.
DISADVANTAGES:
1. The results are not as precise as BOD test.
2. Unable to differentiate between biologically oxidable and biologically
inert organic matter.
RESULT:
The determined COD of our sample was 176 mg/L

23. DETERMINATION OF CHLORIDE
Here we use
REACTIONS :
 Na Cl + AgNO3 = Ag Cl + NaNO3
 H2S + 2AgNO3 = Ag2S + 2HNO3
 K2Cr2O4 + 2AgNO3 = AgCrO4 + 2KNO3
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Mohr method

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After running the procedure and doing
the calculation , here comes
………………..RESULT  …………........
Chloride content = 8 mg/l
According to WHO the tolerable limit of Chloride in
water is 250 mg/l. So, we can say that waste water
sample was safe for environment.
No. Name of REAGENTS
1 Phenolphthalein indicator
2 Methyl orange indicator
3 Potassium chromate indicator
4 Silver nitrate solution
5 0.02 N sulfuric acid

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The ultimate findings of drinking water quality measurements are given in a
tabular form below:
Experiments Result Comment
pH 7.54 Satisfactory.
Carbon Dioxide 6.67mg/L Tolerable amount.
Turbidity 21.62NTU In Bangladesh standard
drinkable.
Alkalinity Bicarbonate
alkalinity; 64.67mg/L
Water is safe, palatable and
less turbid.
Iron 40mg/L Water is safe to drink.
Manganese 0.031mg/L Safe to drink.
Hardness 80mg/L Moderate type of
hardness;drinkable.

26. The results of sewage quality measurements are given below:
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Experiment Result Comment
TS,DS and SS 690mg/L,490mg/L,
200mg/L
Can be accepted.
BOD 72mg/L Greater amount compared
to the standard.
COD 176mg/L Comparatively higher
value.
Chloride 8mg/L Safe amount.

27.  With the result of our experiments we can say that water of first ladies hall
is drinkable. But It will be better if we purify it before drinking. As we have
some limitations with the laboratory machines it can’t be said that our
results give the exact value.
 By experimental results we can say that Wastewater in our hall has no
severe environmental effect. But without any treatment the discharge of
sullage has been mixing to our drainage system and this has an impact on
our environment.
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28. THANK YOU
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