Description : In sewage, the solids in mg per litre is A. 100 to 500 B. 500 to 1000 C. 1000 to 1500 D. 1500 to 2000
Last Answer : ANS: B
Description : A five day B.O.D. at 15°C of the sewage of a town is 100 kg/day. If the 5 day B.O.D. per head at 15°C for standard sewage is 0.1 kg/day, the population equivalent is A. 100 B. 1000 C. 5000 D. 10000
Last Answer : ANS: D
Description : 1000 kg of sewage contains A. 0.112 kg in suspension B. 0.112 kg in solution C. 0.225 kg in solution D. Both A. and C. of above
Description : Primary treatment of sewage consists of removal of A. Large suspended organic solids B. Oil and grease C. Sand and girt D. Floating materials
Last Answer : ANS: A
Description : Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is? A. Centrifugal pump B. Pneumatic ejector C. Reciprocating pump D. None of these
Description : The Brake Horse power of the motor (efficiency 60%) required for a pump of capacity 0.075 cumec for a total lift of 12 m, is A. 10 B. 15 C. 20 D. 25 Q No: 44 Aerobic bacterias A. ... presence of free oxygen B. Consume organic matter as their food C. Oxidise organic matter in sewage D. All the above
Description : Imhoff cone is used to measure A. Total organic solids B. Total solids C. Total in organic solids D. Settleable solids
Description : A cylindrical ejector having its height 2 m fills after every 10 minutes with a peak sewage discharge of 0.0157 cumec. The diameter of the ejector chamber, is A. 2.30 m B. 2.40 m C. 2.45 m D. 2.50 m
Last Answer : ANS: C
Description : The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m
Description : If the pH value of sewage is 7 A. It is acidic B. It is alkaline C. It is neutral D. None of these
Description : Pick up the correct statement from the following: A. pH value indicates acidity and alkalinity of sewage B. In acidic sewage, the pH value is less than 7 C. In alkaline sewage, the pH value is more than 7 D. All the above
Description : WASTE WATER Engineering Objective Questions Pdf :: Q No: 151 The pH value of fresh sewage is usually A. Equal to 7 B. More than 7 C. Less than 7 D. Equal to zero
Description : The grit chambers of sewage treatment plants, are generally cleaned after A. 2 days B. 7 days C. 12 days D. 14 days
Description : In primary sedimentation, the 0.2 mm inorganic solids get separated if specific gravity is A. 2.25 B. 2.50 C. 2.55 D. 2.65
Description : The design period of sewage treatment works in normally A. 5 – 10 years B. 15 – 20 years C. 30 – 40 years D. 40 – 50 years
Description : In a city the ratio of the drainage to sewage is 20, the percentage discharge passing through non-monsoon periods, is A. 5 B. 10 C. 15 D. 20
Description : The spacing of bars of perforations of fine screens used for the treatment of sewage, is A. 2 to 3 mm B. 3 to 5 mm C. 5 to 8 mm D. 8 to 10 mm
Description : The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope A. 1 in 5 B. 1 in 10 C. 1 in 15 D. 1 in 20
Description : 3.0 ml of raw sewage is diluted to 300 ml. The D.O. concentration of the diluted sample at the beginning of the test was 8 mg/l. After 5 dayincubation at 20°C, the D.O. concentration was 5 mg/l. The BOD of raw sewerage is A. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l
Description : For sewer mains of 0.5 to 1 m diameter, the ratio of maximum daily sewage flow to the average daily sewage flow is assumed A. 1.5 B. 2.0 C. 2.5 D. 3.0
Description : The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is A. 1.5 B. 2.0 C. 3.0 D. 4.0
Description : For trunk sewers more than 1.25 m in diameter, the ratio of the maximum daily sewage flow to the average daily sewage flow is assumed A. 1.5 B. 2.0 C. 2.5 D. 3.0
Description : The ratio of maximum sewage flow to average sewage flow for mains up to 1 m in diameter, is A. 1.5 B. 2.0 C. 3.0 D. 4.0
Description : The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is A. 100 cm B. 110 cm C. 120 cm D. 150 cm
Description : 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
Description : Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank. A. Both A and R is true and R is the correct ... is not a correct explanation of A C. A is true but R is false D. A is false but R is true
Description : In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above
Description : The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q
Description : To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is A. 0.50 m/sec B. 0.60 m/sec C. 0.70 m/sec D. 0.75 m/sec
Description : Imhoff cone is used to determine A. Settleable solids B. Suspended solids C. Dissolved solids D. None of these
Description : The effluent of a septic tank is A. Fit for discharge into any open drain B. Foul and contains dissolved and suspended solids C. As good as that from a complete treatment D. None of these
Description : Chlorination of water is done for the removal of A. Bacterias B. Suspended solids C. Sediments D. Hardness
Description : For evaporation and measurement of settable solids, the apparatus used, is A. A jar B. A breaker C. A test tube D. An Imhoff cone
Description : 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
Description : 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
Description : 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
Description : 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
Description : 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
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : Aerobic activity is maximum A. In freshly produced sewage B. At sewer pipes C. In sewer treatment plants D. None of these
Description : To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of A. Hydrochloric acid B. Sulphuric acid C. Nitric acid D. Citric acid
Description : The sewer which transports the sewage to the point of treatment, is called A. House sewer B. Out-fall sewer C. Branch sewer D. Main sewer
Description : During purification process of sewage the gas given off, is A. Carbon dioxide B. Hydrogen C. Ammonia D. All the above
Description : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
Description : Rate of flow of sewage is generally assumed A. More than the rate of water supply B. Equal to the rate of water supply C. Less than the rate of water supply D. At 150 litres per capita
Description : Removal of oil and grease from sewage, is known A. Screening B. Skimming C. Filtration D. None of these
Description : The ratio of minimum hourly flow to the average flow of sewage is A. 1/4 B. 1/3 C. 1/2 D. 3/4
Description : Q No: 291 The coagulant widely used for sewage treatment, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
Description : The sewer pipe which carries sewage from a building for immediate disposal is A. House sewer B. Lateral sewer C. Intercepting sewer D. Main sewer
Description : When drainage to sewage ratio is 20, the peak dry weather flow is A. 20% of the design discharge B. Slightly less than 5% of the design discharge C. Slightly more than 5% of the design discharge D. None of these