The presence of free ammonia in sewage, is detected by___________________?
(A) Boiling
(B) Adding potassium permanganate
(C) Adding sulphuric acid
(D) Phenol-di-sulphuric acid
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
Disposal to sewage in large cities, is done in__________________?
(A) Irrigation
(B) Dilution
(C) Oxidation
(D) Purification
The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is_____________________?
(A) 204 cu.m
(B) 208 cu.m
(C) 212 cu.m
(D) 216 cu.m
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 algae dies out in the zone of_____________________?
(A) Degradation
(B) Active decomposition
(C) Recovery
(D) Cleaner water
In olden days the type of section adopted in trunk and out fall sewers was__________________?
(A) Parabolic shaped
(B) Horse shoe shaped
(C) Egg shaped
(D) Circular shaped
Which one of the following resists hydrogen sulphide corrosion ?
(A) R.C.C.
(B) Glazed stone wares
(C) Asbestos cement
(D) Glazed ware
The ratio of design discharge to the surface area of a sedimentation tank is called____________________?
(A) Surface loading
(B) Overflow rate
(C) Overflow velocity
(D) All of these
Discrete or granular particles change their_________________ ?
(A) Size
(B) Shape
(C) Weight
(D) None of these