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 : 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 : 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
Last Answer : (c) petroleum industry
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 : 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 : 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 : In the context of the chemical process industries, the term BOD is normally associated with the (A) Characterisation of solid wastes (B) Organic concentration in gaseous effluents (C) Characterisation of liquid effluents (D) Characterisation of boiler feed water
Last Answer : (C) Characterisation of liquid effluents
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 : 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
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 : 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 : 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.
Last Answer : Biochemical oxygen demand
Description : Water used for mixing concrete should be [ A ] Slightly acidic [ B ] Free from bacteria [ C ] Distilled [ D ] Potable
Last Answer : [ D ] Potable
Description : Write a note on Biological Oxygen Demands (BOD)
Last Answer : It is a measure of water pollution level due to sewage and other organic matter. Biological oxygen demands {BOD} is the amount of oxygen needed by microbs to decompose the organic matters of water in ... amount of sewage waste in water create at high BOD, which robs the water of dissolved oxygen.
Description : Aerobic biological oxidation ponds used for the purification of polluted water (A) Destroys/removes pathogen from the sewage (B) Is not very effective for non-biodegradable substances (e.g. ABS) containing effluents (C) ... much more effectively if the sewage is chlorinated (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : . Potable water means the water used for (A) Fire-fighting (B) Cooling (C) Drinking (D) Evaporation to produce steam
Last Answer : (C) Drinking
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 : 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 : 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
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
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.
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 : Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these
Last Answer : ANS: D
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 : (2) amount of oxygen used for biochemical oxidation Explanation: Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to ... quantitative test, although it is widely used as an indication of the organic quality of water.
Last Answer : The addition of gypsum to port-land cement helps in : (1) increasing the strength of cement (2) rapid setting of cement (3) preventing rapid setting of cement (4) reduction in the cost of cement
Description : Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by (A) Biological oxygen pond (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate) (C) Lagoons (D) Filtration
Last Answer : (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
Description : Which one of the following weeds is effective in controlling water pollution caused by industrial effluents? (1) Parthenium (2) Elephant grass (3) Water hycinth (4) Molar grass
Last Answer : (3) Water hycinth Explanation: Water hyacinth (Eichhornia crassipes) is used for purifying not only domestic wastewater but also industrial wastewater. It can readily absorb, accumulate and ... hyacinth can remove even radioactive metals from industrial effluents, which is very difficult otherwise.
Description : Which of the following weeds has been found useful to check water pollution caused by industrial effluents? (1) Partheniurn (2) Elephant grass (3) Water hyacinth (4) Both (1) and (2)
Last Answer : (4) Both (1) and (2) Explanation: Parthenium and Elephant grass are useful to check water pollution caused by industrial effluents.
Description : What are the steps taken before releasing the industrial effluents into water bodies?
Last Answer : a) Industrial effluents must be treated to remove the pollutants. b) Toxic chemical substances must be eliminated. c) Acid and alkalies must be neutralized. d) Metallic compounds must be precipitated
Description : The primary source of organic pollution in fresh water bodies is (A) run-off urban areas (B) run-off from agricultural forms (C) sewage effluents (D) industrial effluents
Last Answer : (C) sewage effluents
Description : Main pollutant of the Indian coastal water is (A) oil spill (B) municipal sewage (C) industrial effluents (D) aerosols
Last Answer : (C) industrial effluents
Description : Which one of the following weeds is effective in controlling water pollution caused by industrial effluents? (1) Parthenium (2) Elephant grass (3) Water hycinth (4) Mogar grass
Last Answer : Water hycinth
Description : Reverse osmosis is normally used for the (A) Separation of isotopes of uranium from gaseous uranium hexafluoride (B) Separation of helium from natural gas (C) Desalination of brackish water to produce potable (drinking) water (D) Purification of oxygen
Last Answer : (C) Desalination of brackish water to produce potable (drinking) water
Description : What are the ways of treating industrial effluents? -Geography
Last Answer : To minimize the effects of pollution The hot waters and effluents could be treated before releasing it into the rivers. This treatment could be done in 3 phases: 1. Primary treatment: By ... indigenous, water-borne micro-organisms. 3. Tertiary: The wastewater is recycled in the tertiary stage.
Description : Explain three phases by which treatment of industrial effluents can be done. -Geography
Last Answer : To reduce the use of water by using it more than two times by reusing and recycling it. To meet the water requirements, make use of rainwater harvesting. Before releasing wastewater and industrial effluents ... air. By using oil or gas rather than coal, smoke could be reduced to a certain extent.
Description : Explain three phases by which treatment of industrial effluents can be done? -SST 10th
Last Answer : (i) Primary treatment by mechanical means. This involves screening, grinding flocculation and sedimentation. (ii) Secondary treatment by biological process. (iii) Tertiary treatment by biological chemical and physical processes. This involves recyling of waste water.
Description : “Treatment of industrial effluents can be done in three phases.” Mention them. -SST 10th
Last Answer : The three phases are: (i) Primary treatment by mechanical means. This involves screening, grinding,flocculation and sedimentation. (ii) Secondary treatment by biological process. (iii) Tertiary treatment by biological, chemical and physical processes. This involves recycling of waste water.
Description : Give reason: Most Indian rivers are polluted by industrial effluents.
Last Answer : Waste materials from industries containing enormous quantities of chemicals are released into the nearby rivers. Hence most Indian rivers are polluted.
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 detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of __________ of water. (A) Dissolved oxygen content (B) Biological oxygen demand (C) Vapor pressure (D) All (A), (B) and (C)
Last Answer : (A) Dissolved oxygen content