Description : The function of sedimentation tank in sewage treatment is to: (1) Disinfect the sewage (2) Remove water content (3) Aerate the sewage (4) Remove suspended solids
Last Answer : (4) Remove suspended solids Explanation: The function of sedimentation tank in the sewage treatment is to remove suspended solids.
Description : During sewage treatment, effluent from which one of the following treatment units has minimum wt/vol amount of suspended solids? (a) Detritus channel (b) Primary sedimentation tank (c) Secondary sedimentation tank (d) Activated sludge process aeration tank
Last Answer : (d) Activated sludge process aeration tank
Description : The function of skimming tank in sewage treatment is to remove – (1) oil and fatty substances (2) suspended solids (3) gritty substances (4) inorganic substances
Last Answer : (1) oil and fatty substances Explanation: Oil and grease traps are small size skimming basins provided to remove oil and grease and other small floating materials such as fats, vegetable debris, ... content of wastewater rise to the surface of wastewater and remains on top of liquid until removed.
Description : The function of skimming tank in sewage treatment is to remove (1) oil and fatty substances (2) suspended solids (3) gritty substances (4) inorganic substances
Last Answer : oil and fatty substances
Description : The function of skimming tank in sewage treatment is to remove __________ substances. (A) Dissolved solid (B) Suspended solid (C) Oil & fatty (D) Gritty & inorganic
Last Answer : (C) Oil & fatty
Description : Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted waterstream? (A) Sedimentation tank (B) Circular clarifier (C) Mechanical flocculation (D) Chemical coagulation
Last Answer : (D) Chemical coagulation
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 : The domestic sewage in large cities (a) has a high BOD as it contains both aerobic and anaerobic bacteria (b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in ... sewage contains adequate oxygen (d) has very high amount of suspended solids and dissolved salts.
Last Answer : (b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
Description : Which of the following in sewage treatment removes suspended solids? (a) Secondary treatment (b) Primary treatment (c) Sludge treatment (d) Tertiary treatment
Last Answer : (b) Primary treatment
Description : Which of the following in sewage treatment removes suspended solids ? (1) Secondary treatment (2) Primary treatment (3) Sludge treatment (4) Tertiary treatment
Last Answer : (2) Primary treatment
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 : During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank. (A) Filtration (B) Digestion (C) Sedimentation (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
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 : Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal (A) By chemical coagulation (B) In sedimentation tanks equipped with mechanical scrapper (C) In vacuum filter (D) In clarifiers
Last Answer : (B) In sedimentation tanks equipped with mechanical scrapper
Description : Which two gases are used to disinfect water in sewage treatment facilities? w) helium and nitrogen x) ozone and chlorine y) oxygen and hydrogen z) nitrogen and chlorine
Last Answer : ANSWER: X -- OZONE AND CHLORINE
Description : In domestic sewage, suspended solids, colloidal and dissolved materials constitute
Last Answer : In domestic sewage, suspended solids, colloidal and dissolved materials constitute A. 0.1 B. 0.056 C. 0.027 D. 0.001
Description : To remove very fine suspended particles from water, the method adopted is (A) Screening (B) Sedimentation (C) Boiling (D) Filtration
Last Answer : To remove very fine suspended particles from water, the method adopted is (A) Screening (B) Sedimentation (C) Boiling (D) Filtration
Description : Indicate which of the statement is incorrect (a) The detritus tank is type of a grit chamber (b) In detritus tank, velocity of flow is further reduced (c) Grit chambers are provided in the sewage ... to remove the heavier inorganic matter as grit, sand etc. from the sewage (d) None of them*
Last Answer : (d) None of them*
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
Last Answer : ANS: B
Description : In sewage treatment, its sedimentation is speeded up by commonly adding (A) Hydrochloric acid (B) Lime (C) Copper sulphate (D) Sodium sulphate
Last Answer : (B) Lime
Description : Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low (A) Hardness (B) Dissolved solids content (C) Suspended solids content (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Why sedimentation tanks help to remove solid wastes in the treatment of waste water?
Last Answer : Need answer
Description : How does sedimentation tanks help to remove soid wastes in the treatment of waste water?
Last Answer : Feel Free to Answer
Description : Pick out the true statement pertaining to water treatment. (A) Slow sand filters can remove colour completely (B) Activated carbon can be used for taste & odour control without subsequent filtration ... of water (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation
Last Answer : (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation
Description : Which is the most practical and economical method for removal of suspended solid matter from polluted water? (A) Sedimentation (B) Skimming off (C) Chlorination (D) Biological oxidation
Last Answer : (A) Sedimentation
Description : Very fine suspended and colloidal impurities are removed from water by a process called (A) Sedimentation (B) Coagulation (C) Disinfection (D) Softening
Last Answer : (B) Coagulation
Description : Separation of solid suspended in liquid into a supernatant clear liquid and a denser slurry employs a process termed as the (A) Coagulation (B) Flocculation (C) Sedimentation (D) Clarification
Last Answer : (C) Sedimentation
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
Last Answer : ANS: D
Description : If a force greater than that of gravity is used to separate solids & fluidsof different densities, the process is termed as the (A) Sedimentation (B) Flocculation (C) Dispersion (D) Centrifugation
Last Answer : (D) Centrifugation
Description : The process by which fine solids is removed from liquids is termed as (A) Decantation (B) Flocculation (C) Sedimentation (D) Classification
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
Last Answer : ANS: C
Description : Fine grit present in sewage is removed in the __________ during sewage treatment. (A) Grit chamber (B) Detritus tank (C) Trickling filter (D) Skimming tank
Last Answer : (B) Detritus tank
Description : The main type of sludge gas evolved during sewage treatment in Imhoff tank is (A) CO2 (B) CH4 (C) CO (D) H2
Last Answer : (B) CH4
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : The most commonly used substance to speed up the sedimentation of sewage is (A) Lime (B) Sulphuric acid (C) Chlorine (D) Sodium bisulphite
Last Answer : (A) Lime
Description : Before discharging the foul sewage into rivers, it is generally treated by (a) screening (b) sedimentation (c) Oxidation (d) sludge digestion and disinfection (e) all the above*
Last Answer : e) all the above*
Description : Chlorination of water is done for the removal of A. Bacterias B. Suspended solids C. Sediments D. Hardness
Description : Presence of __________ in water stream are deleterious to aquatic life. (A) Soluble and toxic organics (B) Suspended solids (C) Heavy metals and cyanides (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Turbidity of water is an indication of the presence of (A) Suspended inorganic matter (B) Dissolved solids (C) Floating solids (D) Dissolved gases
Last Answer : (A) Suspended inorganic matter
Description : Removal of __________ is accomplished by aeration of water. (A) Dissolved gases (B) Suspended solids (C) Dissolved solids (D) None of these
Last Answer : (A) Dissolved gases
Description : Which of the following is the most lethal water pollutant? (A) Phenol and cyanide (B) Chlorine (C) Alkalis (D) Suspended solids
Last Answer : (A) Phenol and cyanide
Description : Turbidity of raw water is a measure of (A) Suspended solids (B) Acidity of water (C) B.O.D. (D) None of these
Last Answer : (A) Suspended solids
Description : Imhoff cone is used to determine A. Settleable solids B. Suspended solids C. Dissolved solids D. None of these
Description : Tabular bowl centrifuges as compared to disk bowl centrifuges (A) Operate at higher speed (B) Employ bowl of larger diameter (C) Can’t be operated under pressure/vacuum (D) Can’t be used for separation of fine suspended solids from a liquid
Last Answer : (A) Operate at higher speed
Description : Which of the following is the most suitable filter for separation ofabrasive solids suspended in a corrosive liquid? (A) Sand bed filter (B) Plate and frame filter press (C) Vacuum filter (D) Batch basket centrifuge
Last Answer : (C) Vacuum filter
Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream
Last Answer : (A) Incurs smaller pressure drop
Description : The settlement of a particle in sedimentation tank, is affected by A. Velocity of flow B. Viscosity of water C. Size and shape of solid D. All the above
Description : In a sedimentation tank, the detention period for water ranges from __________ hours. (A) 2 to 4 (B) 8 to 12 (C) 16 to 20 (D) 24 to 32
Last Answer : (A) 2 to 4
Description : The flow of water gets retarded, in (A) Settling tank (B) Sedimentation tank (C) Clarifier (D) All the above
Last Answer : (D) All the above
Description : Distribution of wash water is provided in (A) Sedimentation tank (B) Slow sand filter (C) Rapid gravity filter (D) All the above
Last Answer : (C) Rapid gravity filter