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 __________ substances. (A) Dissolved solid (B) Suspended solid (C) Oil & fatty (D) Gritty & inorganic
Last Answer : (C) Oil & fatty
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.
Last Answer : 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 : __________ substances present in sewage are removed in grit chamber during sewage treatment. (A) Organic (B) Fatty (C) Inorganic (D) Dissolved
Last Answer : (C) Inorganic
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 : 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 : 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 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 : 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
Last Answer : ANS: D
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 : A shallow pond in which the sewage is retained and biologically treated is called (A) Oxidation (B) Imhoff tank (C) Lagoon (D) Skimming tank
Last Answer : (A) Oxidation
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 : 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 : Removal of oil and grease from sewage, is known A. Screening B. Skimming C. Filtration D. None of these
Last Answer : ANS: B
Description : Equilibrium moisture of a solid is equal to the total moisture minus free moisture. Which of the following substances will have maxi-mum equilibrium moisture? (A) Anthracite coal (B) Rag paper (C) Bamboo (D) Inorganic solids
Last Answer : (C) Bamboo
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 : 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 : Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers
Description : A masonry structure built below ground level, where biochemical reaction takes place due to anaerobic bacteria is called (A) Cesspool (B) Lagoon (C) Skimming mill (D) Septic tank
Last Answer : (D) Septic tank
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 : 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 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 : Fine organic or inorganic particles suspended in air is called --------? A. particulate pollutant B. gaseous pollutant C. aerosol (Answer) D. none of these
Last Answer : C. aerosol (Answer)
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 : Imhoff cone is used to determine A. Settleable solids B. Suspended solids C. Dissolved solids D. None of these
Description : Chlorination of water is done for the removal of A. Bacterias B. Suspended solids C. Sediments D. Hardness
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 : 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 : 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 : 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 : 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 : Which of the following statements is not true about triacylglycerols? (a) When solids and semisolids at room temperature, they are called fats. (b) When liquids at room temperature, they are ... low melting points are composed of saturated fatty acids, causing them to be liquids at room temperature
Last Answer : Triacylglycerols with low melting points are composed of saturated fatty acids, causing them to be liquids at room temperature
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 : 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 : 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 : When sufficient energy through mechanical mixing is supplied to keep the entire contents, including the sewage solids, mixed and aerated, the reactor is termed : (a) An aerobic lagoon (b) An aerobic pond (c) A facultative lagoon (d) A facultative pond
Last Answer : (a) An aerobic lagoon
Description : The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by (A) Biological oxygen pond (B) Aerated lagoons (C) Trickling filters (D) Gravity separator having oil skimming devices
Last Answer : (D) Gravity separator having oil skimming devices
Description : Name two inorganic substances which are used by autotrophs to make food. -Science
Last Answer : Carbon dioxide and Water.
Description : What are the processes that autotrophic beings use to produce organic material from inorganic substances ?
Last Answer : Autotrophic beings make organic material by photosynthesis or by chemosynthesis. There are photosynthetic autotrophs, like plants, and chemosynthetic autotrophs, like some bacteria.
Description : Which is correct about transport of conduction of substances? (a) Organic food moves up through phloem (b) Organic food moves up through xylem (c) Inorganic food moves upwardly and downwardly through xylem (d) Organic food moves upwardly and downwardly through phloem
Last Answer : (d) Organic food moves upwardly and downwardly through phloem
Description : Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances. (A) Radioactive (B) Organic (C) Inorganic (D) None of these