Which of the followings is mainly produced by the activity of anaerobic bacteria on sewage?
Propane
Mustard gas
Marsh gas
Marsh gas
C.
Marsh gas
The decomposition of sludge by anaerobic bacteria in sewage-treatment processes produces marsh gas(methane).
Consider the following four statements (a–d) and select the option which includes all the correct ones only:
Single cell Spirulina can produce large quantities of food rich in protein, minerals, vitamins etc.
Body weight-wise the microorganism Methylophilus methylotrophus may be able to produce several times more proteins than the cows per day.
Common button mushrooms are a very rich source of vitamin C.
A rice variety has been developed which is very rich in calcium.
Statements (III), (IV)
Statements (I), (III) and (IV)
Statements (II), (III) and (IV)
Statements (II), (III) and (IV)
Which of the following helps in absorption of phosphorus from the soil by plants?
Rhizobium
Frankia
Anabaena
Anabaena
Nitrifying bacteria
convert free nitrogen to nitrogen compounds
convert proteins into ammonia
reduce nitrates to free nitrogen
reduce nitrates to free nitrogen
Secondary sewage treatment is mainly a
mechanical process
chemical process
biological process
biological process
