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
Last Answer : ANS: B
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 : 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
Last Answer : ANS: D
Description : In very first stage of decomposition of the organic matter in sewage A. Nitrites are formed B. Nitrates are formed C. Carbondioxide is formed D. Ammonia is formed
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 : Which among the following is used as a catalyst in the production of high octane fuels? (1) HNO3 (2) H2SO4 (3) HCl (4) HF
Last Answer : (2) H2SO4 Explanation: Sulfuric acid is used as a catalyst for refining and for producing alkylate, an essential component of highoctane fuel. The hydrocarbon molecules are reformed into more complex molecules with a higher octane rating value.
Description : Aquaregia is a mixture of the following in the ratio 1 : 3 by volume– (1) cone. HNO3 and cone. HCL (2) conc. HNO3 and conc. H2SO4 (3) dil. HCl and dil. HNO3 (4) cone. HCl and cone. HNO3
Last Answer : (3) dil. HCl and dil. HNO3 Explanation: Aqua regia or nitro-hydrochloric acid is a highly corrosive mixture of acids which is formed by freshly mixing concentrated Nitric acid (HNO3) and Hydrochloric acid (HCl), optimally in a volume ratio of 1:3. It is used in dissolving gold.
Description : Glass lined vessels are not used for handling/storing (A) Dilute H2SO4 (B) Dilute HNO3 (C) Dilute HCl (D) Hydrofluoric acid
Last Answer : (D) Hydrofluoric acid
Description : The electrolyte in a lead-acid battery is a) H2SO4 b) HNO3 c) HCl d) NaCl Ans. a
Last Answer : ans a
Description : For conduct of forced degradation studies under acidic conditions, which of the following substance is used? A. HCl B. H2SO4 C. HNO3 D. Citric acid
Last Answer : A. HCl
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 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 : 54 Pick up the correct statement from the following: A. The ratio of the quantity of the diluting water to that of the sewage, is known as dilution factor B. The automatic purification of polluted ... phenomenon C. The photosynthesis is carried out in the presence of sun light D. All the above
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 : Benzene reacts with concentrated HNO3 in the presence of concentrated H2SO4 to give nitrobenzene. This reaction is an example of (a) Electrophilic addition (b) Nucleophilic addition (c) Electrophilic substitution (d) Nucleophilic substitution
Last Answer : Electrophilic substitution
Description : . Glass reacts with (A) H2SO3 (B) HF (C) HNO3 (D) K2Cr2O7
Last Answer : (B) HF
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
Last Answer : ANS: C
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
Description : Collin’s Reagent is? a. K2Cr2O7/H2SO4 b. PCC/CH2Cl2 c. PDC/DCM d. CrO3/pyridine
Last Answer : d. CrO3/pyridine
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 : 2 ml each of concentrated HCl, HNO3 and a mixture of concentrated hydrochloric acid and Concentrated nitric acid in the ratio of 3:1were taken in test tubes labelled as A, B and C, A small piece of metal was put in ... the metal dissolved in test tube C. The metal could be: A) Al B) Au C) Pt D) Cu
Last Answer : B) Au
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 : 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 : 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 : 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 : 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 : Q No: 291 The coagulant widely used for sewage treatment, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
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 : 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 : 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 : 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 : Fresh sewage is generally A. Alkaline B. Acidic C. Highly decomposed D. A source of objectionable odour
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
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 following is the physical characteristic of sewage A. Turbidity B. Colour C. Odour D. All the above
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 liquid wastes from kitchens, bath rooms and wash basins, is not called A. Liquid waste B. Sullage C. Sewage D. None of these