Description : The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known A. Bio-Chemical Oxygen Demand (B.O.D.) B. Dissolved Oxygen (D.O.) C. Chemical Oxygen Demand (C.O.D.) D. None of these
Last Answer : ANS: B
Description : If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is A. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l
Last Answer : ANS: D
Description : 5 days-biochemical oxygen demand (BOD5) is taken at a temperature of A. 0°C B. 15°C C. 20°C D. 25°C
Last Answer : ANS: C
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 : 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
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 : Pick out the wrong statement. (A) Biological oxygen demand (BOD) is a characteristic and not a constituent of water (B) BOD is a measure of the amount of oxygen which will be demanded & used in 5 days ... BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water) (D) None of these
Last Answer : (D) None of these
Description : Pick out the correct statement. (A) Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present in water (B) COD is determined by oxidising the organic matter present in water with potassium dichromate ... of potable water may be 1-2 mg/litre (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The grit chambers of sewage treatment plants, are generally cleaned after A. 2 days B. 7 days C. 12 days D. 14 days
Description : If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is A. 50 mg/l B. 100 mg/l C. 150 mg/l D. 250 mg/l
Description : If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is A. 50 ppm B. 100 ppm C. 150 ppm D. 200 ppm
Description : If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is A. 200 ppm B. 225 ppm C. 250 ppm D. None of these
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
Description : In normal conditions, the period for sludge digestion, is A. 10 days B. 20 days C. 30 days D. 60 days
Description : The first stage of neutral process of sludge digestion, is A. Acid fermentation B. Acid regression C. Alkaline fermentation D. None of these
Last Answer : ANS: A
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 : 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 : It is customary to design a sewer for D.W.F. on the basis of A. Average demand B. Twice the average demand C. Thrice the average demand D. Four times the average demand
Description : The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is A. 0.05552 cumec B. 0.05554 cumec C. 0.05556 cumec D. 0.0556 cumec
Description : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receving effluents from:
Last Answer : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receving ... sewage C. Dairy industry D. Petroleum industry
Description : High value of BOD (Biochemical Oxygen Demand) indicates that:
Last Answer : High value of BOD (Biochemical Oxygen Demand) indicates that: A. Highly polluted water B. Less ... in water C. Less sewage D. Less microorganisms.
Description : BOD (biological oxygen demand) is
Last Answer : BOD (biological oxygen demand) is A. Amount of oxygen consumed by microorganisms for decaying organic ... plants for survival D. None of the above
Description : Drained sewage has biological oxygen demand `(BOD)`:
Last Answer : Drained sewage has biological oxygen demand `(BOD)`: A. More than that of water B. Less than that of ... equal to that of water D. None of the above
Last Answer : High value of BOD (Biochemical Oxygen Demand) indicates that: A. consumption of organic matter in ... is highly polluted D. water is less polluted
Description : Measuring Biochemical Oxygen Demand (BOD) is a method used for:
Last Answer : Measuring Biochemical Oxygen Demand (BOD) is a method used for: A. Measuring the activity of ... out the efficiency of oil driven automobile engines
Description : Biochemical oxygen demand (BOD) in a river water
Last Answer : Biochemical oxygen demand (BOD) in a river water A. Increases when sewage gets mixed with river ... water D. Gives a measure of Salmonella in water
Description : Biological oxygen demand (BOD) is a measure of
Last Answer : Biological oxygen demand (BOD) is a measure of A. Industrial wastes poured into water bodies ... Amount of oxygen needed by green plants during night
Description : Biological Oxygen Demand (BOD) is a measure of: a. Industrial wastes poured into water bodies b. Extent to which water is polluted with organic compounds c. Amount of carbon monoxide inseparably combined with haemoglobin d. Amount of oxygen needed by green plants during night
Last Answer : Ans: A
Description : BOD stands for : (1) Biological oxidation demand (2) Biological oxygen demand (3) Biochemical oxygen demand (4) Biotic oxidation demand
Last Answer : (3) Biochemical oxygen demand Explanation: BOD stands for Biochemical Oxygen Demand. It is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a ... in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20°C.
Description : Biochemical oxygen demand (BOD) in a river water (a) has no relationship with concentration of oxygen in the water (b) gives a measure of Salmonella in the water (c) increases when sewage gets mixed with river water (d) remains unchanged when algal bloom occurs.
Last Answer : (c) increases when sewage gets mixed with river water
Description : Measuring Biochemical Oxygen Demand (BOD) is a method used for (a) estimating the amount of organic matter in sewage water (b) working out the efficiency of oil driven automobile engines ... commercial scale (d) working out the efficiency of RBCs about their capacity to carry oxygen.
Last Answer : (a) estimating the amount of organic matter in sewage water
Description : High value of BOD (Biochemical Oxygen Demand) indicates that (a) water is less polluted (b) consumption of organic matter in the water is higher by the microbes (c) water is pure (d) water is highly polluted.
Last Answer : (b) consumption of organic matter in the water is
Description : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from (a) domestic sewage (b) dairy industry (c) petroleum industry (d) sugar industry.
Last Answer : c) petroleum industry
Description : Measuring Biochemical Oxygen Demand (BOD) is a method used for (a) estimating the amount of organic matter in sewage water (b) working out the efficiency of oil driven automobile engines (c) ... a commercial scale (d) working out the efficiency of RBCs about their capacity to carry oxygen.
Last Answer : (b) consumption of organic matter in the water is higher by the microbes
Last Answer : (c) petroleum industry
Description : The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the (A) Bacterial stability factor (B) Relative stability (C) Biological oxygen demand (BOD) (D) Oxygen ion concentration
Last Answer : (B) Relative stability
Description : The term Biological Oxygen Demand (BOD) is used in relation to (A) Potable water (B) Cooling water (C) Distilled water (D) Industrial effluents
Last Answer : (D) Industrial effluents
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 : Water pollution can be identified by testing its A. PH level B. Biological Oxygen Demand (BOD) C. Both (a) and (b) D. None of these.
Last Answer : C. Both (a) and (b)
Description : ater pollution can be identified by testing its A. PH level B. Biological Oxygen Demand (BOD) C. Both (a) and (b) D. None of these.
Description : Biochemical Oxygen Demand (BOD) of sewage is the (a) Oxygen required to oxidise (b) Oxygen required to oxidise biologically inactive organic matter* (c) a and b both (d) none of these
Last Answer : (b) Oxygen required to oxidise biologically inactive organic matter*
Description : 72. Measuring Biochemical Oxygen Demand (BOD) is a method used for (1) Working out the efficiency of R.B.Cs. about their capacity to carry oxygen (2) Estimating the amount of ... driven automobile engines (4) Measuring the activity of Sacccharomyces cerevisae in producing curd on a commercial scale
Last Answer : Estimating the amount of organic matter is sewage water
Last Answer : Biochemical oxygen demand
Description : A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2 . It means that (A) 21% excess air has been used for combustion (B) 21% excess oxygen has ... (C) Complete combustion of fuel has taken place (D) No excess air has been used for combustion
Last Answer : (C) Complete combustion of fuel has taken place
Description : Presence of carbonaceous matter in the sewage (A) Causes reduction in its dissolved oxygen content thereby endangering the life of aquatic creatures (B) Reduces sulphate ions to sulphides causing obnoxious ... quantity of chlorine used for its purification (D) All (A), (B) and (C)
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
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