A. Bio-Chemical Oxygen Demand (B.O.D.)
B. Dissolved Oxygen (D.O.)
C. Chemical Oxygen Demand (C.O.D.)
D. None of these
Related Mcqs:
- If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is_________________?
A. 100 mg/l
B. 200 mg/l
C. 300 mg/l
D. 400 mg/l - If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is_____________________?
A. 50 ppm
B. 100 ppm
C. 150 ppm
D. 200 ppm - If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is_________________?
A. 50 mg/l
B. 100 mg/l
C. 150 mg/l
D. 250 mg/l - If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is____________________?
A. 200 ppm
B. 225 ppm
C. 250 ppm
D. None of these - To maintain aerobic biological activity, the moisture content of the compost mass should be about_________________?
A. 45 %
B. 50 %
C. 55 %
D. 60 % - Pathogens (or pathogenic bacterias) in water may cause___________________?
A. Typhoid
B. Cholera
C. Dysentery
D. All the above - The sewage treatment units in which anaerobic decomposition of organic matter is used, are called________________?
A. Imhoff tanks
B. Trickling filters
C. Sludge sedimentation tanks
D. None of these - Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities_________________?
A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not a correct explanation of A
C. A is true but R is false
D. A is false but R is true - The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is_____________________?
A. 0.05552 cumec
B. 0.05554 cumec
C. 0.05556 cumec
D. 0.0556 cumec - If q is the average sewage flow from a city of population P, the maximum sewage flow______________?
A. Q = [(4 + )/(18 + )] q
B. Q = [(18 + P)/(4 + )] q
C. Q = [(18 + )/(4 + )] q
D. Q = [(5 + )/((15 + )] q
