Environmental Engineering

141.Phenolic water generated in coke ovens&by-product plant of a steel plant are disposed off by

1. Quenching of hot coke
2. Discharging in the river stream
3. Filtration and recycling for cooling coke oven gas
4. None of these

142.Photochemical smog is formed from automobile exhaust

1. By reaction of hydrocarbon&nitric oxide in presence of sunlight
2. Appears only on sunny days
3. Is harmful for crops and trees also besides causing eye irritation&asthma
4. All (A), (B)&(C)

143.Pick out the correct statement.

1. Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present in water
2. COD is determined by oxidising the organic matter present in water with potassium dichromate in cone, sulphuric acid solution at boiling temperature for specified time
3. COD is related to BOD of a given waste in water but the relationship varies for different wastes. Typically COD of potable water may be 1-2 mg/litre
4. All (A), (B) and (C)

144.Pick out the one which is not a chemical coagulant.

1. Aluminium sulphate
2. Ferrous sulphate
3. Hydrated lime
4. Chloramine

145.Pick out the wrong statement

1. Low ozone layer thickness in polar regions is due to cold climatic conditions
2. Amount of unburnt hydrocarbons emitted by two stroke petrol engine is more as compared to that emitted by a four stroke engine
3. Carbon monoxide present in the two stroke petrol engine exhaust is much less as compared to that emitted from a four stroke engine
4. Mercury as a pollutant can enter the blood stream&the digestive system/ lungs and is responsible for causing Minamata disease

146.Pick out the wrong statement pertaining to 'green house' for the plants.

1. 'Green house' (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants inside it
2. The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house
3. 'Green house effect' in earth's atmosphere is due to increasing CO₂ level in atmosphere, where CO₂ acts like the glass of 'green house' thereby warming up the earth's surface
4. 'Green house' is colder than the outside atmosphere '

147.Pick out the wrong statement.

1. The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere
2. Stratosphere is rich in ozone and is located just above the troposphere
3. Troposphere is a turbulent dusty zone containing much of water vapor and clouds
4. The earth's atmosphere is an envelope of gases extending upto a height of about 200 kms

148.Pollution by particulate matter emission in the atmosphere does not take place during metal

1. Grinding
2. Machining
3. Cutting
4. Polishing

149.Polyvinyl chloride containers are not suitable for storing

1. Foodstuffs
2. Woolen clothes
3. Metallic powder
4. None of these

150.Presence of _________ bacteria in water causes disease like typhoid.

1. Aerobic
2. Pathogenic
3. Anaerobic
4. Non-pathogenic