Description : The coagulant which is generally not used for treating the sewage, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
Last Answer : ANS: A
Description : Which is the most widely used coagulant for the treatment of turbid water? (A) Alum (aluminium sulphate) (B) Lime (C) Ferric chloride (D) Sodium aluminate
Last Answer : (A) Alum (aluminium sulphate)
Description : Most widely and commonly used coagulant for the removal of suspended impurities in water is (A) Bleaching powder (B) Slaked lime (C) Alum (D) Copper sulphate
Last Answer : (C) Alum
Description : The most widely used coagulant for removing suspended impurities from water is (A) Bleaching powder (B) Chlorine (C) Calcium sulphate (D) Alum
Last Answer : (D) Alum
Description : Q No: 131 The most widely used pump for lifting sewage is A. Centrifugal pump B. Reciprocating pump C. Pneumatic ejector D. Air pressure pump
Description : The most commonly used chemical coagulant in water treatment is (A) Ferrous sulphate (B) Alum (C) Lime (D) Hydrazine
Last Answer : (B) Alum
Description : Which of the following is used as a coagulant in treating turbid water? (A) Chlorine (B) Ferric sulphate (C) Calcium sulphate (D) Activated carbon
Last Answer : (B) Ferric sulphate
Description : Alum is chemically (A) Copper sulphate (B) Aluminium sulphate (C) Ferrous sulphate (D) Ferric sulphate
Last Answer : (B) Aluminium sulphate
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
Last Answer : ANS: D
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
Last Answer : ANS: C
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
Last Answer : ANS: B
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 : 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 : 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 : 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 : Alum [Al2 (SO4 )3 ] is used as a coagulant in water treatment to remove (A) Colour (B) Turbidity (C) Bacteria (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
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 : Aerobic activity is maximum A. In freshly produced sewage B. At sewer pipes C. In sewer treatment plants D. None of these
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 : 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 sewage treatment in septic tanks is due to A. Anaerobic decomposition B. Aerobic decomposition C. Parasitic decomposition D. None of these
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 : 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 spacing of bars for perforations in coarse screens used for the treatment of sewage, is A. 20 mm B. 30 mm C. 40 mm D. 50 mm
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 : Primary treatment of sewage consists of removal of A. Large suspended organic solids B. Oil and grease C. Sand and girt D. Floating materials
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 : Dried sewage after treatment is used as A. Fertilizer B. Building material C. Chemical for lowering B.O.D. D. Base material for paints
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 : 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
Description : During preliminary treatment of a sewage A. Oil and grease are removed from skimming tanks B. Floating materials are removed by screening C. Girt and sand are removed by girt chambers D. All the above
Description : The sewer that unloads the sewage at the point of treatment is called A. Main sewer B. Outfall sewer C. Branch sewer D. House sewer
Description : Aluminium salt commonly used to stop bleeding is - (1) Aluminium nitrate (2) Aluminium sulphate (3) Aluminium Chloride (4) Potash alum
Last Answer : (2) Aluminium sulphate Explanation: Alum (Aluminium Sulfate) is used to stop bleeding. For example, Styptic pencils containing aluminium sulfate are used as astringents to prevent bleeding from small shaving cuts. It constricts blood vessels to stop the flow of blood.
Description : Chemical name of 'alum' is (A) Barium sulphate (B) Aluminium sulphate (C) Aluminium chloride (D) Calcium sulphate
Description : Aluminium salt commonly used to stop bleeding is (1) Aluminium nitrate (2) Aluminium sulphate (3) Aluminium Chloride (4) Potash alum
Last Answer : Aluminium sulphate
Description : Ferrous sulphate is used in water treatment as a/an - (1) Oxidizing agent (2) Reducing agent (3) Coagulant aid (4) Adsorbent
Last Answer : (3) Coagulant aid
Description : Which of the following is used as a coagulant in water treatment? (A) Chloramine (B) Chlorine (C) Ferrous sulphate (D) Hydrogen peroxide
Last Answer : (C) Ferrous sulphate
Description : Ferrous sulphate is used in water treatment as a/an (1) Oxidizing agent (2) Reducing agent (3) Coagulant aid (4) Adsorbent
Last Answer : Coagulant aid
Description : Natural rubber is obtained from latex, which is a colloidal dispersion of rubber in water. Which of the following is used as a coagulant in latex? (A) Ammonium alum (B) Potassium alum (C) Both ‘a’ & ‘b’ (D) Neither ‘a’ nor ‘b
Last Answer : (C) Both ‘a’ & ‘b
Description : The purpose of adding Na2CO3 to water of low alkalinity is to (A) Permit the use of alum as a coagulant (B) Increase the softening capacity of zeolite (C) Facilitate easy regeneration of zeolite (D) All (A), (B) and (C)
Last Answer : (A) Permit the use of alum as a coagulant
Description : Temporary hardness of water can be removed by (A) Addition of alum (a coagulant) (B) Boiling (C) Filtration (through gravity sand filter) (D) Addition of lime
Last Answer : (B) Boiling
Description : Alum is a (A) Coagulant (B) Flocculent (C) Catalyst (D) Disinfectant
Last Answer : (A) Coagulant
Description : Mostly used coagulant, is (A) Chlorine (B) Alum (C) Lime (D) Bleaching powder
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : In 1000 kg of sewage, the total solids approximate A. 0.5 to 1.0 kg B. 1 kg to 2.0 kg C. 5 kg to 7.5 kg D. 7.5 kg to 10 kg
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 : During purification process of sewage the gas given off, is A. Carbon dioxide B. Hydrogen C. Ammonia 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 : 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