Description : Q No: 291 The coagulant widely used for sewage treatment, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
Last Answer : ANS: B
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 : 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 : 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
Last Answer : ANS: D
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 : 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
Last Answer : ANS: A
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 : 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 : Alum is chemically (A) Copper sulphate (B) Aluminium sulphate (C) Ferrous sulphate (D) Ferric sulphate
Last Answer : (B) Aluminium sulphate
Description : Foul odour and bad taste of water is removed by treating with (A) Alum (B) Bleaching powder (C) Activated carbon (D) Copper sulphate
Last Answer : (C) Activated carbon
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
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 : 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 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
Last Answer : ANS: C
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 : 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 : 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 : 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 : 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 : 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 : 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 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 : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
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 : 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
Description : The non-clog pump which permits solid matter to pass out with the liquid sewage, is A. Centrifugal pump B. Reciprocating pump C. Pneumatic ejector D. None of these
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 : The sewage is pumped up A. From low lying areas B. From flat areas C. From basements D. All the above
Description : In sewage having fully oxidised organic matter, the nitrogen exists in the form of A. Nitrites B. Nitrates C. Free ammonia D. Aluminoid nitrogen
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 presence of free ammonia in sewage, is detected by A. Boiling B. Adding potassium permanganate C. Adding sulphuric acid D. Phenol-di-sulphuric acid
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 : Disposal to sewage in large cities, is done in A. Irrigation B. Dilution C. Oxidation D. Purification
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 : The sewage treatment in septic tanks is due to A. Anaerobic decomposition B. Aerobic decomposition C. Parasitic decomposition D. None of these
Description : A rain sanitary sewer is constructed to carry A. Sanitary sewage B. Storm sewage C. Surface water D. Ground water
Description : For detecting the nitrites in the sewage, the matching colour may be developed by adding A. Potassium permanganate B. Sulphuric acid and napthamine C. Phenol-di -sulphuric acid potassium hydroxide D. None of these
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