A. 15 days
B. 30 days
C. 60 days
D. 90 days
Related Mcqs:
- The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is_______________?
A. 25 %
B. 50 %
C. 10 %
D. 5 % - In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is____________________?
A. [(100 + P1)/(100 – P2)] V1
B. [(100 – P1)/(100 + P2)] V1
C. [(100 – P1)/(100 – P2)] V1
D. [(100 + P2)/(100 – P1)] V1 - The first stage of neutral process of sludge digestion, is__________________?
A. Acid fermentation
B. Acid regressio
C. Alkaline fermentation
D. None of these - In normal conditions, the period for sludge digestion, is_______________?
A. 10 days
B. 20 days
C. 30 days
D. 60 days - pH value of sludge during alkaline regression stage, is__________________?
A. More than 7
B. Less than 7
C. Less than 6
D. More than 6 - The digested sludge from septic tanks, is removed after a maximum period of__________________?
A. 3 years
B. 3.5 years
C. 4 years
D. 5 years - The rate of accumulation of sludge in septic tanks is recommended as____________________?
A. 30 litres/person/year
B. 25 litres/person/year
C. 30 litres/person/month
D. 25 litres/person/month - In the activated sludge process__________________?
A. Aeration is continued till stability
B. Aeration is done with an admixture of previously aerated sludge
C. Sludge is activated by constant stirring
D. Water is removed by centrifugal action - Sludge banks are formed if sewage is disposed of in____________________ ?
A. Rivers
B. Seas
C. Lakes
D. None of these - The rate of accumulation of sludge per person per year, is_______________________?
A. 10 litres
B. 15 litres
C. 20 litres
D. 25 litres
