Description : Nitrogen cycle of sewage, is A. Liberation of ammonia-formation of nitrites-formation of nitratesliberation of nitrogen B. Liberation of nitrogen-liberation of ammonia-formation of ... of ammonia D. Formation of nitrates-formation of nitrites-liberation of nitratesliberation of nitrates
Last Answer : ANS: A
Description : During purification process of sewage the gas given off, is A. Carbon dioxide B. Hydrogen C. Ammonia D. All the above
Last Answer : ANS: D
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 : In sewage having fully oxidised organic matter, the nitrogen exists in the form of A. Nitrites B. Nitrates C. Free ammonia D. Aluminoid nitrogen
Last Answer : ANS: B
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 : For detecting the nitrates in sewage, the colour may be developed by adding A. Potassium permanganate B. Sulphuric acid and napthamine C. Phenol-di -sulphuric acid and potassium hydroxide D. None of these
Description : A well oxidized sewage contains nitrogen mainly as A. Nitrates B. Nitrites C. Free ammonia D. None of these
Description : Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of (1) Nitrates (2) Zeolites (3) Sulphonates (4) None of these
Last Answer : (2) Zeolites Explanation: Zeolites are crystalline solids structures made of silicon, aluminum and oxygen that form a framework with cavities and channels inside where cations, water and/or small molecules may reside.
Description : Injurious effects of sulphates can be replaced with the addition of ________: a. Nitrates b. Phosphates c. Ammonia d. Ca & Mg
Last Answer : Nitrates
Description : Hardness of water can be removed by boiling if it is due to (A) Calcium bicarbonates (B) Calcium sulphates (C) Calcium chloride (D) Calcium nitrates
Last Answer : (A) Calcium bicarbonates
Description : Which of the following is a primary pollutant in atmospheric air? A. Cl2 B. SO3 C. Nitrates D. Sulphates
Last Answer : A. Cl2
Description : If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains A. Hydrogen sulphide B. Carbon dioxide C. Methane D. Oxygen
Description : In sewers the gas generally found, is A. Hydrogen sulphide (H2S) B. Carbon dioxide (CO2) C. Methane (CH4) D. All the above
Description : In a sludge tank, the gas mainly produced, is A. Oxygen B. Nitrogen C. Hydrogen D. Carbon dioxide
Description : If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains A. Hydrogen sulphide B. Carbon dioxide C. Methane D. Oxygen
Description : If the flame of a miner’s safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains A. Hydrogen sulphide B. Carbon dioxide C. Methane D. Oxygen
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : Disposal to sewage in large cities, is done in A. Irrigation B. Dilution C. Oxidation D. Purification
Description : Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other ... of A C. A is true but R is false D. A is false but R is true
Description : Which one of the following gases is most significant as air pollutant? A. Carbondioxide B. Oxygen C. Nitrogen D. Sulphur-dioxide
Description : The gas which may cause explosion in sewers, is A. Carbondioxide B. Methane C. Ammonia D. Carbon monoxide
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 correct statement from the following: A. The materials separated by screens, is called screenings B. The screenings are disposed off either by burning or by burial or by dumping C. The process of burning the screenings, is known as compositing D. All the above
Description : In the activated sludge process A. Aeration is continued till stability B. Aeration is done with an admixture of previously aerated sludge C. Sludge is activated by constant stirring D. Water is removed by centrifugal action
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 : 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 : Nitrogen oxidation (nitrification)refers to the A- conversion of ammonium ions into nitrates through the activities of certain bacteria B- changing of atmospheric nitrogen (N2) to nitrogen compounds C- sulfur is oxidized to the sulfate form through Thiobacillusbacteria D- none of the above
Last Answer : conversion of ammonium ions into nitrates through the activities of certain bacteria
Description : Conversion achieved in HNO3 synthesis with the use of platinum catalyst is about 95-97%. The rate of formation of nitrogen dioxide from the oxidation of nitric acid is favoured by (A) Decreasing the pressure (B) Decreasing the temperature (C) Increasing the temperature (D) None of these
Last Answer : (C) Increasing the temperature
Description : What is the oxidation state of oxygen in carbon dioxide?
Last Answer : The oxidation state of oxygen in carbon dioxide is 2-.
Description : Pick up the correct statement from the following: (A) Rusting is caused due to combined action of air, moisture and carbon dioxide (B) During rusting, first ferrous bicarbonates are formed (C) On further oxidation ferrous bicarbonates get converted to ferric bicarbonates (D) All the above
Last Answer : Answer: Option D
Description : The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation
Last Answer : [ D ] carbonation
Description : Sewer manholes are generally provided at A. The change of gradient B. The change of direction C. The junctions of sewers D. All of these
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 : If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity is A. 1 in 60 B. 1 in 100 C. 1 in 120 D. None of these
Description : hydraulically equivalent, the relationship which holds good, is A. D8/3 = 4 b8/3 B. D3/8 = 4 b3/8 C. D2/3 = 4 b2/3 D. D3/2 = 4 b3/2
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 : Sewer pipes need be checked for A. Minimum flow B. Maximum flow C. Both A. and B. 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 : 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 : The sewerage system originates from A. House sewers B. Lateral sewers C. Branch sewers D. Main sewers
Description : The gas evolved in sewers is A. Carbondioxide B. Hydrogen sulphide C. Methane D. All of these
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 : Drop manholes at the junctions of sewer lines, are provided if A. Invert level of a branch sewer is more than 60 cm that of the main sewer B. Sewer line runs along a main road C. Ordinary manhole cannot be built D. Two sewer lines intersect
Description : If is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is A. D² B. D² C. D² D. D²
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 : The small sewers are cleaned by A. Flushing B. Cane rodding C. Wooden pills D. None of these
Description : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
Description : The standard B.O.D. of water is taken for A. 1 day B. 2 days C. 3 days D. 5 days