Environmental Studies · General Awareness
Water Quality and Pollution
1,303 Questions
Water Quality and Pollution examines the sources, mechanisms, and impacts of contaminants in aquatic ecosystems. It covers crucial environmental concepts like eutrophication, biochemical oxygen demand, and thermal pollution. This subject frequently appears in general science and environmental studies sections of various examinations.
Eutrophication CausesThermal Pollution EffectsBiochemical Oxygen DemandSynthetic Fertilizer ImpactsWastewater SourcesAquatic Ecosystem Toxicity
Water Quality and Pollution Questions
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biological oxygen demand (BOD) increases
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water becomes less harmful
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biological oxygen demand (BOD) decreases
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algae are destroyed
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biological oxygen demand (BOD) remains constant
A
Correct answer
Explanation
Due to eutrophication the BOD (biological oxygen demand) increases.
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Salinization
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Eutrophication
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Biomagnification
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Global warming
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Ozone depletion
B
Correct answer
Explanation
Eutrophication is characterized by excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis such as sunlight, carbon dioxide and nutrient fertilizers. This can be a problem in marine habitats such as lakes, as it can cause algal blooms.
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A glass of drinking water
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Water which kept in a large open pot
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Sea water
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Water with bacteria and chemicals
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Water of a pond
A
Correct answer
Explanation
Potable water is the water which is used for drinking purposes. So a glass of drinking water is potable water.
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Heavy particles floats on the surface of water.
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Flowing water dissolves many soluble minerals present in the soil.
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Salt makes water muddy.
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Dirty water does not carry diseases that kill.
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None of these
B
Correct answer
Explanation
Yes, flowing water dissolves many soluble minerals present in the soil. These minerals are generally soluble in water.
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Fungi
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Parasites
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Algae
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Tiny animals
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Dead and decaying organic matter
C
Correct answer
Explanation
Algae have green colour as they contain chlorophyll.
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Spirulina
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Charophyta
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Chlorella
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Brown algae
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Chlamydomonas
C
Correct answer
Explanation
Chlorella is a genus of single cell green algae, which belongs to the phylum Chlorophyta. Our body is contaminated with heavy metals from dental fillings, after receiving a vaccine by the use of certain types of cookware or eaten fish.
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Coliform bacteria
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Magnesium metal
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Fluorine
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Oil
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Sewage
A
Correct answer
Explanation
The coliform bacteria, if present in water, contaminates water and the water is not safe to drink.
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thermal pollution
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sewage pollution
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nuclear pollution
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organic pollution
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inorganic pollution
A
Correct answer
Explanation
Thermal pollution makes water gain or lose temperature, which affects the aquatic life in a bad way. Thermal pollution is the result of release of very hot water or very cool water from industries into water bodies.
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sewage disposal in rivers
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oxygen depletion
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oil spillage in ocean
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agricultural pollution of water
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industrial pollution of water
B
Correct answer
Explanation
'Eutrophication' is a process in which the water body becomes enriched with nutrients. This can be a problem in marine habitats as it can cause algal blooms. The algae may use up all the oxygen in the water leaving none for other marine life. This results in the death of many aquatic organisms such as fishes, which need the oxygen in the water to live.
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It is a rotten vegetable.
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It is an organic chemical.
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It is waste water that contains garbage.
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It is the term used for waste water that contains dead fish in water.
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It is the term used for rain water that mixes with drainage.
C
Correct answer
Explanation
'Sewage' is the term used for waste water that contains human waste, faeces, urine, laundry waste, etc.
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high levels of nutrients in water.
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high aquatic productivity
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algal blooms
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low nutrients and low productivity
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high salt content in water
D
Correct answer
Explanation
Oligotropic lakes have low nutritional content and productivity due to higher pollution content in water, thereby decreasing its productivity.
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more, less
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less, medium
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medium, more
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less, more
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more, more
A
Correct answer
Explanation
Biochemical oxygen demand is more in polluted water and less in potable water. A low BOD is an indicator of good quality water, while a high BOD indicates polluted water. There are generally no standards for an absolute BOD value of drinking water. However, a sample with a BOD between 1 and 2 mg/L indicates a very clean water.
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contamination by human wastes
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phosphorus contamination
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decreased biological oxygen demand
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hydrocarbon contamination
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none of the above
A
Correct answer
Explanation
Total coliforms are a group of bacteria commonly found in the environment, for example in soil or vegetation as well as the intestines of mammals, including humans. Total coliform bacteria are not likely to cause illness, but their presence indicates that your water supply may be vulnerable to contamination by more harmful microorganisms present through animal or human waste.
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more, less
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less, medium
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medium, more
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less, more
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more, more
A
Correct answer
Explanation
Biochemical oxygen demand is more in polluted water and less in potable water. A low BOD is an indicator of good quality water, while a high BOD indicates polluted water. There are generally no standards for an absolute BOD value of drinking water. However, a sample with a BOD between 1 and 2 mg/L indicates a very clean water.
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By reducing the mineral concentration
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By increasing the temperature of water bodies
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By increasing the pressure in water bodies
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By reducing the carbon dioxide level of water bodies
B
Correct answer
Explanation
Oil spills and industrial effluents affect the water bodies by increasing the temperature of water bodies.