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
Last Answer : ANS: C
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 : Dry weather flow is: A. Average daily rate of flow B. Average monthly rate of flow C. Average annual rate of flow D. Water supply allowance per capita
Last Answer : ANS: D
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
Last Answer : ANS: A
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
Last Answer : ANS: B
Description : No treatment of the sewage is given if dilution factor is A. Less than 150 B. Between 150 to 200 C. Between 200 to 300 D. More than 500
Description : For design of sewers, percentage of sewage discharge is assumed A. 65 to 70% B. 70 to 75% C. 75 to 80% D. 85%
Description : 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
Description : Dilution method of disposing of sewage, is not preferred to A. When sewage is fresh B. When diluting water has high dissolved oxygen content C. When diluting water is used for water supply near the point of sewage disposed D. When the diluting water is having flow currents
Description : Pick up the correct statement from the following: A. The water supply pipes carry pure water free from solid particles B. The water supply pipes get clogged if flow velocity is less than self ... carried up and down the hills and valleys D. The sewer pipes are generally laid along level hills
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
Description : The rate of accumulation of sludge per person per year, is A. 10 litres B. 15 litres C. 20 litres D. 25 litres
Description : A rural water supply serves a population of 10, 000 at the rate of 50 litres per capita per day . For the chlorine dose of 2 PPM the required amount of bleaching powder with 20% available chlorine will be a. 0.5 kg b. 5 kg * c. 10 kg d. 15 kg
Last Answer : b. 5 kg
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 : 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 : In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time? A. 100 mm dia. B. 150 mm dia. C. 225 mm dia. D. All of these
Description : The discharge per unit plan area of a sedimentation tank, is generally called A. Over flow rate B. Surface loading C. Over flow velocity D. All the above
Description : The requirement of water per capita per day, is (A) 90 litres (B) 150 litres (C) 250 litres (D) 400 litres
Last Answer : (A) 90 litres
Description : Pick up the incorrect statement from the following: A. The mixture of water and waste products, is called sewage B. The treated sewage effluents, are generally used for irrigating the ... is called sewerage D. The old convergence system was definitely better than water carried sewerage system
Description : The normal values of over flow rates for secondary sedimentation tanks, ranges between A. 25,000 to 35,000 litres/sqm/day B. 40,000 to 50,000 litres/sqm/day C. 50,000 to 60,000 litres/sqm/day D. 80,000 to 10,000 litres/sqm/day
Description : The normal value of over flow rates for plain primary sedimentation tanks, ranges between A. 25,000 to 35,000 litres/sqm/day B. 40,000 to 50,000 litres/sqm/day C. 50,000 to 60,000 litres/sqm/day D. 80,000 to 100,000 litres/sqm/day
Description : The normal values of over flow rates for sedimentation tanks using coagulant, ranges between A. 25,000 to 35,000 litres/sqm/day B. 40,000 to 50,000 litres/sqm/day C. 50,000 to 60,000 litres/sqm/day D. 80,000 to 100,000 litres/sqm/day
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : Fresh sewage is generally A. Alkaline B. Acidic C. Highly decomposed D. A source of objectionable odour
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 : The coagulant which is generally not used for treating the sewage, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
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 design purposes, the normal rate of infiltration of ground water into the sewer, is A. 500 litres/km/cm B. 1000 litres/km/cm C. 1500 litres/km/cm D. 2000 litres/km/cm
Description : If the grit in grit chambers is 4.5 million litres per day, its cleaning is done A. Manually B. Mechanically C. Hydraulically D. Electrically
Description : 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
Description : If V is total consumption of water in litres for a population of N individuals, per capita consumption or water allowance for the water supply Q, is given by (A) Q = V/12N (B) Q = V/24N (C) Q = V/265N (D) None of these
Last Answer : (C) Q = V/265N
Description : Dry water flow in a combined sewer, is A. Industrial sewage B. Domestic sewage C. Storm water D. Inclusive of domestic and industrial sewage but excludes storm water
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 : The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these
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 : 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 : 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 : 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 : 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 : Sewer ventilating columns are generally placed at A. Distances 150 m to 300 m B. Upper ends of branch sewers C. Every change in the size of sewers D. All the above
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
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 : 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
Description : For treating the sewage of a large city, you will recommend A. A sedimentation tank and an activated sludge treatment plant B. A plant consisting of Imhoff tanks with low rate trickling filters C. Sedimentation tanks with high rate trickling filters D. None of these
Description : Q No: 251 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
Description : Q No: 271 Pick up the correct statement from the following: A. Turbidity is more in strong sewage B. The black colour indicates septic sewage C. The sewage omits offensive odours after four hours D. All the above
Description : A rain sanitary sewer is constructed to carry A. Sanitary sewage B. Storm sewage C. Surface water D. Ground water
Description : The water carried sewerage system removes A. Domestic sewage B. Industrial sewage C. Storm sewage D. All the above
Description : WASTE WATER ENGINEERING Objective Questions with Answers Q No: 161 The quantity of liquid waste which flows in sewers during the period of rainfall, is known A. Sanitary sewage B. Industrial waste C. Storm sewage D. None of these