The lowest layer of atmosphere is known as the Troposphere None of these Ionosphere Stratosphere TRUE ANSWER : ? YOUR ANSWER : ?
Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. Potassium cyanide Coal ash Ortho-xylene None of these TRUE ANSWER : ? YOUR ANSWER : ?
Removal of __________ is accomplished by aeration of water. Suspended solids Dissolved gases None of these Dissolved solids TRUE ANSWER : ? YOUR ANSWER : ?
The main type of sludge gas evolved during sewage treatment in Imhoff tank is CH₄ H₂ CO CO₂ TRUE ANSWER : ? YOUR ANSWER : ?
Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes Poor visibility due to sky darkening Irritation in eyes Respiratory trouble All of these TRUE ANSWER : ? YOUR ANSWER : ?
A shallow pond in which the sewage is retained and biologically treated is called Skimming tank Lagoon Imhoff tank Oxidation TRUE ANSWER : ? YOUR ANSWER : ?
The upper layer of atmosphere is called the Ionosphere Troposphere Stratosphere None of these TRUE ANSWER : ? YOUR ANSWER : ?
Dust collection efficiency of a cyclone separator depends upon its All of these Diameter Inlet gas velocity Overall height TRUE ANSWER : ? YOUR ANSWER : ?
BOD of raw municipal sewage may be in the range of about __________ mg/litre. 2000-3000 5-10 1-2 150-300 TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is the most lethal water pollutant? Suspended solids Phenol and cynide Alkalis Chlorine TRUE ANSWER : ? YOUR ANSWER : ?