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 chemistry synthetic fibres and plastics plastic and environment pollution due to plastics environmental impact: plastics

Phosphate ions from fertilizers are sometimes present as contaminants in municipal sewage. These have been removed with some success by:

  1. passing of chlorine
  2. heating at $70^{\circ}C$

  3. filtration

  4. passing of steam
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heating sewage to 70 degrees Celsius can help precipitate or remove certain phosphate compounds, though modern methods often use chemical precipitation.

Multiple choice physics electric charges and fields conductors and insulators introduction to electrostatics electricity

Ordinary tap water conducts electric current due to :

  1. the dissolved salts in it

  2. higher purity of the water

  3. the bacteria present in it

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tap water conducts electricity since there are small amounts of calcium and magnesium salts dissolve in it, pure water (distilled or de-ionised) has nothing at all in it that can conduct electricity. This is because water itself isn't a conductor. However, when one dissolves ionic compound such as salts, the ions becomes loosely bound to each other which makes tap water a good conductor of electricity. 

Multiple choice geography pollution - types and sources environmental risks of economic development tundra climatic region effects and successes of environment conservation

 The presence of high coliform counts in water indicate ______________.

  1. phosphorus contamination.

  2. hydrocarbon contamination.

  3. contamination by human wastes.

  4. decreased biological oxygen demand.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The presence of high coliform counts in water indicate contamination by human wastes.

Coliform bacteria or Escherichia coli is a bacteria that is present in human intestine. It is a useful bacteria. When people discharge fecal matter near water bodies these microorganisms enter water.

Water contamination test is done by counting the number of coliform- bacteria E. coli colonies per 100 mL of water. The test is known as coliform microbial density. The water quality standards are that drinking water should not have any colonies, bathing and swimming pool water can have about 200 colonies, and recreational (fishing and boating) water about 1000 colonies

Multiple choice geography pollution - types and sources environmental risks of economic development tundra climatic region effects and successes of environment conservation

Measuring Biochemical Oxygen Demand (BOD) is a method used for _________________.

  1. estimating amount of oxygen in sewage water

  2. estimating amount of organic matter in sewage water

  3. both a and b

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

BOD stands for Biological Oxygen Demand. It is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic matter present in a given water sample. It is mostly expressed in milligrams of oxygen consumed per litre of sample. 

Multiple choice geography pollution - types and sources environmental risks of economic development tundra climatic region effects and successes of environment conservation

How the biological oxygen demand gets affected with the increased presence of organic matter in water?

  1. the oxygen demand decrease

  2. the oxygen demand remains unchanged

  3. the oxygen demand increases

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Biological oxygen demand (BOD) measures the amount of dissolved oxygen required by aerobic microorganisms to decompose organic matter. When more organic matter is present, more oxygen is consumed by these organisms, leading to an increase in BOD.

Multiple choice botany ecological adaptations, succession and ecological services ecosystem services ecosystems ecosystem

Aquatic ecosystem help in

  1. Reduce pollution

  2. Absorption of nutrients

  3. Recycle of nutrients

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

The aquatic ecosystem is the interaction of biotic component and abiotic component in the water body. It serves important environmental services such as recycling of nutrients, water purification, attenuate floods, recharge groundwater and provides shelter to wildlife. Aquatic ecosystems are also used for human recreation, and are very important to the tourism industry, especially in coastal regions. 

Multiple choice botany ecological adaptations, succession and ecological services ecosystem services ecosystems ecosystem

Identify the correct statement for freshwater ecosystems.
I. There is a seasonal mixing of materials.
II. During the year, oxygen concentrations are vertically uniform.
III. Materials are recycled more quickly than in ocean ecosystems.

  1. I only

  2. II only

  3. III only

  4. I and III

  5. II and III

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A Freshwater ecosystem is one of  the aquatic ecosystems of the earth and includes lakes, ponds, rivers, streams and wetlands. This ecosystem is essential as it not only provides human beings their drinking water, but these are also home to more than 40 percent of the world's fish species. The seasonal changes occur in the freshwater ecosystem with regards to temperature-density relationship and since it contains continuous running water so materials are recycled more quickly than in ocean ecosystems.

So, the correct answer is option D.

Multiple choice biology interdependence in living beings - plants and animals animals as consumers scavengers and decomposers interdependence between plants and animals

Read the following statements and select the incorrect one.

  1. Little decomposition occurs during the formation of primary sludge

  2. formation of primary sludge requires ample aeration.

  3. Activated sludge possess flocs of decomposer microbes

  4. Formation of activated sludge requires aeration.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Little decomposition occurs during the formation of primary sludge. Activated sludge possess flocs of decomposer microbes. Formation of activated sludge requires aeration. But formation of primary sludge does not requir ample aeration. So, the correct option is 'Formation of primary sludge requires ample aeration'

Multiple choice economics environmental economics study of water pollution threats to water resource major hazards in india and prevention

Water pollution is any chemical, physical or biological change in the quality of water that has a harmful effect on any living thing that drinks or uses it. Given below are all the examples of main water pollutants except:

  1. stone crushing and construction work

  2. oil tankers, offshore oil refineries

  3. industrial effluents, waste water

  4. soil erosion, use of chemical fertilizers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Stone crushing and construction work are examples of air and noise pollution respectively.

Multiple choice types, sources and impact of waste accumulation waste management - impact of waste accumulation our life and environment geography

Addition of phosphates and nitrates/fertilizers into water leads to ________.

  1. Increased algal growth

  2. Nutrient enrichment/ eutrophication

  3. Increased growth of decomposers

  4. Reduced algal growth
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Addition of phosphates and nitrates/fertilizers into water leads to nutrient enrichment which is also called as eutrophication. It is the enrichment of water bodies with excessive nutrients and fertilizers. This is a kind of water pollution, because excessive nutrients result in growth of plants and algae which consume oxygen present.

Multiple choice types, sources and impact of waste accumulation waste management - impact of waste accumulation our life and environment geography

Eutrophication means __________.

  1. excessive richness of nutrients in a water body or lake due to run off

  2. decrease in growth of algae

  3. increase in fertility of soil

  4. all the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Addition of phosphates and nitrates/fertilizers into water leads to nutrient enrichment which is also called as eutrophication. 
  • This is a kind of water pollution, because excessive nutrients result in growth of plants and algae over water surface which consume oxygen present and obstructs the light from entering the water.