(i) (a) Carbon Monoxide:
Carbon monoxide is a poisonous gas produced as a result of incomplete combustion of coal are firewood. It is released into the air mainly by automobile exhaust. It binds with haemoglobin and form carboxy haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.
(b) Carbon dioxide:
Carbon dioxide is released into the atmosphere mainly by the process of respiration, burning of fossil fuels, forest fire, decomposition of limestone in cement industry etc.Green plants can convert CO₂ gas in the atmosphere into carbohydrate and oxygen through a process called photosynthesis. The increased CO₂ level in the atmosphere is responsible for global warming. It causes headache and nausea.
ii) a) Carbon Monoxide :
It binds with haemoglobin and form carbory haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.
b) Carbon dioxide :
It causes headache and nausea.

(i) Thus Greenhouse effect may be defined as the heating up of the earth surface due to trapping of infrared radiations reflected by earth's surface by CO₂ layer in the atmosphere.
(ii) The heating up of earth through the greenhouse effect is called global warming.
(iii) Without the heating caused by the greenhouse effect, Earth's average surface temperature would be only about -18 ^oC (0 ^oF). Although the greenhouse effect is a naturally occurring phenomenon, it is intensified by the continuous ernission of greenhouse gases into the atmosphere.
(iv) During the past 100 years, the amount of carbon dioxide in the atmosphere increased by roughly 30 percent and the amount of methane more than doubled. If these trends continue, the average global temperature will increase which can lead to melting of polar ice caps and flooding of low lying areas. This will increase incidence of infectious diseases like dengue, malaria, etc.

a) The growth of algae in extreme abundance covers the water surface and reduces the oxygen concentration in water. Thus, bloom-infested water inhibits the growth of other living organisms in the water body. This process in which the nutrient rich water bodies support a dense plant population, kills animal life by depriving it of orygen and results in loss of biodiversity is known as eutrophication.
b) Chemicals from industries
c) Toxic pesticides
d) Detergents and oil floats
e) Acids from mine drianage and salts from various sources.

i. Bio-degradable pollutants :
The pollutants which can be easily decomposed by the natural biological processes are called bio-degradable pollutants.
Examples: plant wastes, animal wastes, etc.
ii. Non bio-degradable pollutants :
The pollutants which cannot be decomposed by the natural biological processes are called Non bio-degradable pollutants.
Examples : metal wastes (mainly Hg and Pb), D.D.T, plastics, nuclear wastes, etc., These pollutants are harmful to living organisms even in low concentration. As they are not degraded naturally,it is difficult to eliminate them from our environment.

At high altitudes to the atmosphere consists of a layer of ozone (O₃) which acts as an umbrella or shield for harmful UV radiations. It protects us from harmful effect such as skin cancer. UV radiation can convert molecular oxygen into ozone as shown in the following reaction.

Ozone gas is thermodynamically unstable and readily decomposes to molecular oxygen.

1. Waste management : Environmental pollution can be controlled by proper disposal of wastes. 
2. Recycling : a large amount of disposed waste material can be reused by recycling the waste, thus it reduces the land fill and converts waste into useful forms.
3. Substitution of less toxic solvents for highly toxic ones used in certain industrial processes. 
4. Use of fuels with lower sulphur content (e.g., washed coal)
5. Growing more trees
6. Control measures in vehicle emissions are adequate.
7. Green chemistry philosophy can be followed.
8. Eco-friendly compounds should be developed.
g. Greener routes should be followed in our day to day life.
10. For dry cleaning liquified CO₂ or H₂O₂ may be used.
11. Paper may be bleached by H₂O₂.
12. Methanol maybe used instead of petrol.
13. Neem based pesticides may be used.
14. Awareness among students and public may be created by using slogans like "Save water; Water will save You".

It binds with haemoglobin and form carboxy haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.

(i) BOD and COD

(ii) Viable and non-viable particulate pollutants