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 : 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 digested sludge from septic tanks, is removed after a maximum period of A. 3 years B. 3.5 years C. 4 years D. 5 years
Description : The first stage of neutral process of sludge digestion, is A. Acid fermentation B. Acid regression C. Alkaline fermentation D. None of these
Description : Pick up the incorrect statement from the following: A. The process of decomposing the organic matter under controlled anaerobic conditions, is called sludge digestion B. Sludge digestion is carried ... contain 75% carbon dioxide D. The gases produced in sludge digestion process, contain 75% methane
Last Answer : ANS: C
Description : The sludge does not contain waste water from A. Bath rooms B. Wash basins C. Kitchen sinks D. Toilets
Last Answer : ANS: D
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 : 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 rate of accumulation of sludge per person per year, is A. 10 litres B. 15 litres C. 20 litres D. 25 litres
Description : Sludge banks are formed if sewage is disposed of in A. Rivers B. Seas C. Lakes D. None of these
Last Answer : ANS: B
Description : pH value of sludge during alkaline regression stage, is A. More than 7 B. Less than 7 C. Less than 6 D. More than 6
Description : In normal conditions, the period for sludge digestion, is A. 10 days B. 20 days C. 30 days D. 60 days
Description : In a sludge tank, the gas mainly produced, is A. Oxygen B. Nitrogen C. Hydrogen D. Carbon dioxide
Description : The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is A. 25 % B. 50 % C. 10 % D. 5 %
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 : 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 : Pick up the correct statement from the following: A. Rate of digestion of sludge is more at higher temperature B. Thermophilic organisms digest the sludge if the temperature ranges from 40° to 60°C C. Mesophilic organisms digest the sludge if the temperature is between 25° and 40°C D. All the above
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 : 11. Acid regression stage of sludge digestion at a temperature 21°C extends over a period of A. 15 days B. 30 days C. 60 days D. 90 days
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 : The disintegrating pump in which solid matter is broken up before passing out, is A. Centrifugal pump B. Reciprocating pump C. Pneumatic ejector D. None of these
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 : 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 : Consider the following statements : Activated sludge process can be said to comprise : 1. Conversion of dissolved organic matter into biological flocs 2. Removal of dissolved BOD of the waste water 3. Digestion of the sludge Which ... 2 and 3 (b) 1 and 2 only (c) 2 and 3 only (d) 1 and 3 only
Last Answer : (b) 1 and 2 only
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 : Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further ... correct explanation of A C. A is true but R is false D. A is false but R is true
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 : In a trickling filter A. Filtration process is used B. Biological action is used C. Neither A. nor B. D. Both A. and B.
Description : What is activated sludge? -Biology
Last Answer : answer:
Description : Select the correct statement from the following. (a) Biogas is produced by the activity of aerobic bacteria on animal waste. (b) Methanobacterium is an aerobic bacterium found in rumen of ... sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria.
Last Answer : (d) Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria.
Description : Which of the following is put into anaerobic sludge digester for further sewage treatment? (a) Primary sludge (b) Floating debris (c) Effluents of primary treatment (d) Activated sludge
Last Answer : (d) Activated sludge
Description : Use of chlorine in the treatment of sewage (A) Helps in grease separation (B) Increases the biological oxygen demand (BOD) (C) Causes bulking of activated sludge (D) Aids in flocculation
Last Answer : (A) Helps in grease separation
Description : Activated sludge contains large number of A.bacteria B.yeasts and molds C.protozoa D.all of these
Last Answer : D.all of these
Description : Testosterone therapy started in a boy of 8 years and continued till puberty is likely to: A. Increase adult stature B. Reduce adult stature C. Have no effect on adult stature D. Cause hypertrophy of penis
Last Answer : B. Reduce adult stature
Description : Traps A. Are water seals which prevent the entry of foul gases B. Are used to trap the rats entering sewers C. Dissolve the foul gases D. Create symphonic action to increase the quick disposal of sewerage
Description : Which of the following is the most common pump for pumping either raw sewage or sludge? (A) Electromagnetic pump (B) Centrifugal pump (C) Reciprocating pump (D) Gear pump
Last Answer : (C) Reciprocating pump
Description : Dissolved carbon dioxide, can be removed from the supply main by (A) Sedimentation (B) Aeration (C) Chlorination (D) Coagulation
Last Answer : (B) Aeration
Description : The value of Chezy’s constant C = 157.6/(1.81 + K/ ) is used in A. Chezy’s formula B. Bazin’s formula C. Kutter’s formula D. Manning’s formula
Description : depends upon The Chezy’s constant C in the formula V = C A. Size of the sewer B. Shape of the sewer C. Roughness of sewer surface D. All the above
Description : Chlorination of water is done for the removal of A. Bacterias B. Suspended solids C. Sediments D. Hardness
Description : With the DPI method of inspection after the contact time has elapsed the dye should be removed by: a) Spraying the surface with the remover till all dye has gone then wipe with clean cloth b) Spraying with ... remover d) it doesn't matter how it is done as long as all traces of dye are removed
Last Answer : c) Wipe clean, using a clean cloth soaked in a solvent remover
Description : In septic tanks, decomposition of organic bacteria, is done by A. Anaerobic bacteria B. Aerobic bacteria C. Both types of bacterias D. None of these
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 : Disposal to sewage in large cities, is done in A. Irrigation B. Dilution C. Oxidation D. Purification
Description : The laying of sewers is done with A. Magnetic compass B. Theodolite C. Level D. Clinometer
Description : Lead acetate test in sewer manhole is done to test the presence of A. Methane gas B. Hydrogen sulphide C. Carbondioxide gas D. Diesel vapours
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 clinical advantage of porcelain laminate veneers over composite resin veneers is: A. Color stability and resistance to abrasion B. Availability of self-curing or light activated placement (yes but not ... dentist's abilities) D. May be used in edge to edge occlusion or Class III relationships.
Last Answer : A. Color stability and resistance to abrasion
Description : During purification process of sewage the gas given off, is A. Carbon dioxide B. Hydrogen C. Ammonia D. All the above
Description : Oxidation process results in the formation of A. Carbon dioxide B. Nitrates C. Sulphates D. All the above