Environment 3 Flashcards
What is the turbidity limit for drinking water as per IS 10500-2010?
Turbidity should be between 5–10 ppm.
New– 1-5 mg/l
What is the acceptable range for the color of drinking water?
The color should be between 5–20 ppm.
New 5 ppm
What is the desirable temperature for drinking water?
10-20 degrees
What is the acceptable range of total solids in drinking water?
500-2000
What is the permissible pH range for drinking water?
6.5-8.5
What is the permissible alkalinity of drinking water?
200 mg/l
What is the limit of chlorides in drinking water?
Chlorides should be ≤250 mg/l.
What is the permissible level of sulphates in drinking water?
Sulphates should be ≤250 mg/l.
New 200
What is the limit for residual chlorine in drinking water?
Residual chlorine should be 0.2 ppm.
What is the maximum permissible level of nitrates in drinking water
45
What is the permissible level of fluoride in drinking water?
1
Less than 1 dental cavity
Greater than 1.5 mottling of teeth
What are the limits for copper (Cu) and manganese (Mn) in drinking water?
Both should be ≤0.05 mg/l.
What is the permissible B.O.D (Biochemical Oxygen Demand) for drinking water?
The B.O.D should be 0.
Hardness of water is caused by presence of the following in water
Calcium and magnesium
If the expected turbidity of water is more than 5000 ppm, the turbidimeter used for analysis
Jackson turbidy meter
Greater than 25 mg/l
MPN is
Most probable number
What is COD (Chemical Oxygen Demand)?
COD is the amount of oxygen required to oxidize both biodegradable and non-biodegradable organic matter.
What is BOD (Biochemical Oxygen Demand)?
BOD is the amount of oxygen required to oxidize biodegradable organic matter.
What is the primary use of BOD?
BOD is used to find the population equivalent and to determine the strength of industrial wastewater.
What disease can be caused by excessive nitrate in water?
Excessive nitrate can cause Methemoglobinemia (blue baby disease).
What gases are produced during anaerobic decomposition?
Anaerobic decomposition produces gaseous products such as methane () and carbon dioxide ().
TH>alkanity
Ch= alkanity
NCh=. TH - CH
Th<alkanity
Ch= th
Nch = 0
The maximum permissible residual chlorine content for public supplies
.1-.2 ppm
The maximum permissible residual chlorine content for public supplies
.1-.2 ppm
Methemoglobinemia is caused if water is supplied with high con
Nitrates
Methemoglobinemia is caused if water is supplied with high con
Nitrates
Zeolite process can lower hardness up to
0 ppm
pH value of drinking water should be in range
6.5-8.5
The standard unit of colour of water is that which is produced by 1 mg of In one liter of distilled water
Platinum cobalt
What is the standard unit of turbidity based on?
The standard unit of turbidity is based on the turbidity produced by one milligram of finely divided silica in one liter of distilled water.
What does NTU stand for, and what is it sometimes referred to as?
NTU stands for Nephelometric Turbidity Unit and is sometimes referred to as FTU (Formazin Turbidity Unit) because formazin polymer is used instead of silica.
What is the classification of water with a hardness of 0–75 ppm?
Water with a hardness of 0–75 ppm is classified as soft water.
How is water with a hardness of 75–150 ppm classified?
Water with a hardness of 75–150 ppm is classified as moderately hard water.
What classification is given to water with a hardness of 150–300 ppm?
Water with a hardness of 150–300 ppm is classified as hard water.
How is water with a hardness greater than 300 ppm classified?
Water with a hardness greater than 300 ppm is classified as very hard water.
Disappearance of the pink colour of water in a well due to KMnO4, indicates that the water contains
Organic matter
For removal of temporary hardness in water
Water is boiled
Zeolite is
Hydrated Aluminosilicate
Coagulants are used when turbidity of water more than
50 ppm
- Intensity of colour of water which is accepted for drinking purpose is about
5ppm
Potassium permanganate is used in water to make it odourless
pH value of potable water should be (2014)
Neutral
In public water supply projects, coagulation is to be adopted when the turbidity of water exeed
40 ppm
Method used for removing permanent hardness
Demineralization process
Lime soda process
Zeolite process
Ion exchange process
Standard unit of turbidity of water is that which is produced by 1 mg of
Fine silica sand
Minimum dissolved oxygen present in the wa- ter in order to save aquatic life
4 ppm
. BOD in potable water
0
A test used for determining the biological qual ity of drinking water is
Coliform test
Lime soda process is used for removing
Permenent hardness
Osmoscope is used for measuring
Odour of water
- The measure of amount of light absorbed or scattered by the suspended material in water
Turbidy
The commonly used indicator for measuring iron concentration in water is
1,10-phenanthroline
Biochemical oxygen demand of waste water represents
Concentration of biodegradable organic. Matter
