Environmental Studies · General Awareness

Water Quality and Pollution

1,263 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

Multiple choice biology air and water pollution control environmental impact: global warming green house effect geobiochemical cycle

Few pollutants and their effects are listed below.
Mark the incorrect match.

  1. Phosphate fertilizers in water - Eutrophication

  2. Hydrogen released in air - Global warming

  3. Sewage disposed in water - Increase in BOD level

  4. Carbon dioxide in air - Acid rain
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Global warming occurs when gases like carbon dioxide and other greenhouse gases in the atmosphere absorb sunlight and solar radiation. They trap the heat and increase the temperature on the earth's surface. 

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Blue-green algae are commonly found growing in paddy fields as they act as a good   

  1. Biofertilizer

  2. Pest controlling agent

  3. Oxygenating organisms

  4. Pollution abatement agent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Blue-green Algae (BGA) is a type of biofertilizer used as an alga form. Important species are Cyanobacteria, Anabaena, Nostoc, Tolypothrix. The algal mat in paddy fields protects loss of moisture from the soil.
A. Bio-fertilizers are eco-friendly are environmentally safe and have low cost. They are widely used in paddy production. The most common bio-fertilizers are Azospirillum, Phosphobacteria, Blue-green algae, Azolla and mycorrhiza.
So the correct answer is "Biofertilizers".
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Main reason of water bloom in rivers, lakes, sea etc., is

  1. Brown algae and Green algae

  2. Cyanobacteria and Dinoflagellates

  3. Eichornia

  4. Fishes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water bloom is a dense aquatic population of microscopic photosynthetic organisms produced by an abundance of nutrient salts in surface water, coupled with adequate sunlight for photosynthesis. The microorganisms or the toxic substances that they release may discolour the water, deplete its oxygen content, poison aquatic animals and waterfowl, and irritate the skin and respiratory tract of humans. It majorly caused because of Cyanobacteria and dinoflagellates. 

Therefore, the correct answer is option B.

Multiple choice geography secondary sector : industry generation of electricity exploration and conservation of minerals irrigation and power

Death of fish in lakes and rivers in some countries has been attributed to _____.

  1. Pollution

  2. Acid rains

  3. Gaseous pollutants

  4. Air toxics
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When humans burn fossil fuel sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere. These gases when react with rain water form nitric and sulphuric acids and result in acid rains. Death of fish in lakes and rivers in some countries has been attributed to such acid rains.

Multiple choice botany adaptations to different ecosystems lichen lichens lichens ( the nature's pioneers )

Which of the following is the use of lichens in case of pollution?

  1. They treat the polluted water

  2. They act as bioindicators of pollution

  3. They promote pollution

  4. Lichens are not related with pollution
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Bioindicators are living organisms that respond in an especially clear way to a change in the environment. The hardy lichens are useful bioindicators for air pollution, especially sulfur dioxide pollution, since they derive their water and essential nutrients mainly from the atmosphere rather than from the soil. It also helps that, they are able to react to air pollutants all year round. Compared with most physical/chemical monitors, they are inexpensive to use in evaluating air pollution.
Lichens can also be used to measure toxic elemental pollutants and radioactive metals because they bind these substances in their fungal threads where they concentrate them over time. Environmental scientists can then evaluate this accumulation to determine the history of the local air
So, the correct answer is 'They act as bioindicators of pollution'
Multiple choice botany adaptations to different ecosystems lichen lichens lichens ( the nature's pioneers )

Lichens are important in the studies on atmospheric pollution because they

  1. Can cause eutrophication

  2. Efficiently purify the atmosphere
  3. Are very sensitive to pollutants like $SO _2$

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.
  • If air is very badly polluted with sulfur dioxide($SO _2$) there may be no lichens present, just green algae may be found. If the air is clean, shrubby, hairy and leafy lichens become abundant
  • Hence Lichens are important in the studies on atmospheric pollution because they are very sensitive to pollutants like sulfur dioxide. 
  • So, the correct answer is ' Are very sensitive to pollutants like $SO _2$.
Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

What is hard water?

  1. Low mineral content

  2. Contaminated water

  3. High mineral content

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates. Hard drinking water may have moderate health benefits, but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other equipment that handles water.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Hard water causes _________ .

  1. burning of skin

  2. scales on the boiler walls

  3. relief to the body

  4. head-ache
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

Hard water contains minerals specifically $Ca,Mg$ and $Fe$ which can dry our skin and cause flaking and itching.

The presence of these minerals also causes scaling in boiler walls as these minerals are less soluble in hot than cold or to the presence of too high concentration of silica in relation to the alkalinity of water in the boiler.

Multiple choice natural vegetation and wildlife of india and world resources of india and world general knowledge

There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon?
1. Discharge of nutrients from the estuaries.
2. Run-off from to land during the monsoon.
3. Upwelling in the seas.
Select the correct answer from the codes given below.

  1. Only 1

  2. 1 and 2

  3. 2 and 3

  4. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Harmful algal blooms (HABs) are triggered by an excess of nutrients in water bodies. Estuarine discharges and monsoon agricultural run-off carry nutrient-rich fertilizers into the sea, while ocean upwelling brings cold, nutrient-rich deep waters to the surface, all of which fuel rapid algal growth.

Multiple choice

Grey water is....

  1. waste water from people's homes (doesn't include sewage).

  2. waste water from people's homes (includes sewage).
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Greywater is relatively clean waste water from baths, sinks, washing machines, and other kitchen appliances. It does not include toilet wastewater, which is classified as blackwater or sewage.

Multiple choice

Which of the following is not a beneficial organism?

  1. phytoplankton that releases oxygen

  2. mold that produces penicillin

  3. bacteria that grows on raw chicken

  4. bacteria in our digestive system
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria growing on raw chicken (such as Salmonella or Campylobacter) are harmful pathogens that can cause severe food poisoning. In contrast, gut bacteria, oxygen-producing phytoplankton, and penicillin-producing mold provide significant benefits to humans and ecosystems.

Multiple choice

Humans’ release of excess phosphates into lakes and rivers can result in

  1. the poisoning of herbivores

  2. phosphate-based gases depleting the ozone layer

  3. acid rain

  4. the overgrowth of aquatic bacteria and algae
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Phosphates are limiting nutrients in aquatic ecosystems. Excess phosphate runoff causes eutrophication, leading to rapid, uncontrolled growth of algae and bacteria.

Multiple choice

How is denitrification different from nitrification?

  1. Denitrification releases N2 gas

  2. Denitrification absorbs N2 gas from the atmosphere

  3. Denitrification involves animals

  4. Nitrification involves animals
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nitrification converts ammonia into nitrates, which plants can use. Denitrification is the process where bacteria convert nitrates back into nitrogen gas, releasing it into the atmosphere.