4.4 Water Pollution (DP IB Environmental Systems & Societies (ESS): SL): Flashcards
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What causes oxygen depletion and harmful algal blooms in water bodies?
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Cards in this collection (73)
What causes oxygen depletion and harmful algal blooms in water bodies?
Excessive organic material, such as untreated sewage, animal waste or decaying plant matter, causes oxygen depletion and harmful algal blooms.
Which two inorganic nutrients from agricultural run-off and fertilisers commonly cause algal overgrowth?
Nitrates and phosphates from agricultural run-off and fertilisers commonly cause algal overgrowth.
Define industrial effluent.
Industrial effluent is wastewater discharged by industrial facilities after use in production processes, often containing heavy metals, toxic chemicals and pathogens.
What pollutants does urban run-off typically pick up as it flows over roads and pavements?
Urban run-off typically picks up pollutants such as oil, grease, pesticides, fertilisers, pet waste and litter.
Rain falling on landfills leaches contaminants into the soil and .
Rain falling on landfills leaches contaminants into the soil and groundwater.
Name three heavy metals that pollute water from industrial activities, mining or improper waste disposal.
Mercury, lead and arsenic are heavy metals that pollute water from industrial activities, mining or improper waste disposal.
True or False?
Heavy metals such as mercury and lead break down quickly and do not accumulate in aquatic organisms.
False.
Heavy metals accumulate in aquatic organisms, leading to toxic effects and risks to human health.
Define synthetic compounds (as water pollutants).
Synthetic compounds are human-made chemicals, such as pesticides, herbicides, pharmaceuticals and industrial pollutants, that enter water bodies.
What effects do high concentrations of suspended solids have in water?
High concentrations of suspended solids impair water clarity, clog fish gills and smother benthic habitats.
How does releasing hot water into aquatic systems affect ecosystems?
Releasing hot water into aquatic systems reduces oxygen levels and disrupts fish migration and breeding cycles.
What disease can pathogens from sewage cause in humans?
Pathogens from sewage can cause waterborne diseases, such as cholera.
Prolonged exposure to radioactive pollution can lead to genetic mutations and .
Prolonged exposure to radioactive pollution can lead to genetic mutations and cancer.
True or False?
Excessive artificial coastal lighting has no effect on marine species' behaviour.
False.
Excessive artificial lighting disrupts natural light cycles, affecting nocturnal species' reproduction, navigation and feeding patterns.
Give a named example of an invasive species causing severe ecological imbalance in US Atlantic coastal waters.
The lionfish is an invasive species causing severe ecological imbalance in US Atlantic coastal waters.
Define microplastics.
Microplastics are small plastic particles less than 5mm in diameter.
Define gyres.
Gyres are large systems of circular ocean currents formed by global wind patterns and the Earth's rotation.
Why do sea turtles often ingest plastic bags?
Sea turtles often mistake plastic bags for jellyfish, leading to ingestion, which can eventually be fatal.
Which seabird has been found with its stomach full of plastic, leading to starvation?
Albatrosses have been found with stomachs full of plastic, leading to starvation.
True or False?
Fishing nets and six-pack rings mainly cause harm to marine animals through ingestion.
False.
They mainly cause harm through entanglement, causing injury or death.
What toxic additive found in plastics can interfere with the reproductive systems of aquatic species?
Bisphenol A (BPA), a toxic additive in plastics, can interfere with the reproductive systems of some aquatic species.
Approximately how many pieces of plastic does the Great Pacific Garbage Patch contain?
The Great Pacific Garbage Patch contains an estimated 1.8 trillion pieces of plastic.
What happens to the concentration of microplastics and their toxins as they move up the food chain?
The concentration of microplastics and their associated toxins increases up the food chain through bioaccumulation and biomagnification.
Which chemicals found on microplastics have been linked to cancer and hormone disruption in animals and humans?
Polychlorinated biphenyls (PCBs) and pesticides found on microplastics have been linked to cancer and hormone disruption.
Polluted beaches and coastal areas can deter , affecting local hotels, restaurants and other businesses.
Polluted beaches and coastal areas can deter tourists, affecting local hotels, restaurants and other businesses.
What has the UK banned to help reduce plastic pollution?
The UK has banned single-use plastic straws, drinks stirrers and cutlery to help reduce plastic pollution.
What is the aim of the Ocean Cleanup project?
The Ocean Cleanup project aims to remove large quantities of plastic from the Great Pacific Garbage Patch and other water bodies using advanced technology.
True or False?
Microplastics only enter the environment from large plastic debris breaking down.
False.
Microplastics also come from products such as cosmetics and clothing.
Plastics can transport invasive species, such as barnacles, on floating debris, potentially outcompeting species.
Plastics can transport invasive species, such as barnacles, on floating debris, potentially outcompeting local species.
Define water quality index (WQI).
The water quality index is a single value or score that combines multiple water quality measurements to assess the overall quality of a water body.
Define turbidity.
Turbidity is a measure of the clarity or cloudiness of water, caused by suspended particles.
Define total suspended solids (TSS).
Total suspended solids (TSS) is the concentration of solid particles suspended in water.
What instrument is used to measure dissolved oxygen in water?
Dissolved oxygen is measured using an oxygen meter equipped with a probe.
What device is lowered into water to measure turbidity, based on the depth at which it disappears from sight?
A Secchi disc, a black and white disc, is lowered into water to measure turbidity based on the depth at which it disappears from sight.
How are nitrate and phosphate concentrations typically measured in water samples?
Nitrate and phosphate concentrations are measured using colorimetric test kits, where a colour change indicates the nutrient concentration.
True or False?
Turbidity and total suspended solids (TSS) measure exactly the same thing.
False.
Turbidity measures the effect of suspended particles on light, while TSS measures the actual mass of suspended particles.
Why is it important to compare water quality readings from various locations, such as upstream and downstream of a factory?
Comparing readings from various locations helps assess the impact of pollution sources, such as a factory, on the ecosystem.
What can low dissolved oxygen levels cause in aquatic organisms?
Low dissolved oxygen levels can cause hypoxia, which can suffocate or kill aquatic life.
Define biochemical oxygen demand (BOD).
Biochemical oxygen demand (BOD) is a measure of the dissolved oxygen required to break down organic material in a given volume of water through aerobic biological activity.
At what temperature and over what incubation period is a BOD test typically carried out?
A BOD test is typically carried out over a 5-day incubation period at a constant temperature of 20°C.
A water sample with an initial dissolved oxygen concentration of 8 mg/L that falls to 2 mg/L after 5 days has a BOD value of mg/L.
A water sample with an initial dissolved oxygen concentration of 8 mg/L that falls to 2 mg/L after 5 days has a BOD value of 6 mg/L.
Which two invertebrates are tolerant of organic pollution and low oxygen levels, and are used as BOD indicator species?
Bloodworms and Tubifex worms are tolerant of organic pollution and low oxygen levels.
True or False?
Mayfly nymphs and stonefly larvae are typically found in heavily polluted, low-oxygen water.
False.
Mayfly nymphs and stonefly larvae are typically only found in clean-water environments.
What does a higher BOD value indicate about a water sample?
A higher BOD value indicates a larger amount of organic matter present in the water sample.
Introducing organic pollutants, such as sewage, increases the population of organisms that break them down, resulting in increased values.
Introducing organic pollutants, such as sewage, increases the population of organisms that break them down, resulting in increased BOD values.
Define eutrophication.
Eutrophication is the process by which water bodies, such as lakes, estuaries and coastal areas, become enriched with excess mineral nutrients, mainly nitrates and phosphates, causing excessive plant and algal growth.
Define algal bloom.
An algal bloom is the rapid growth of algae at the water surface, caused by an excess of available nutrients.
Define hypoxia.
Hypoxia is a state of low oxygen levels in water.
Define anoxia.
Anoxia is the severe or complete depletion of oxygen in water.
Where do most of the excess nitrates that cause eutrophication typically come from?
Excess nitrates that cause eutrophication typically come from agricultural run-off.
Where do most of the excess phosphates that cause eutrophication typically come from?
Excess phosphates that cause eutrophication typically come from detergents and untreated sewage.
Why does an algal bloom cause underwater plants to die?
An algal bloom blocks sunlight from reaching underwater plants, preventing them from photosynthesising.
Why does dissolved oxygen rapidly decrease after phytoplankton and plants die during eutrophication?
Bacteria decompose the dead plants and algae, using up dissolved oxygen through aerobic respiration.
True or False?
Eutrophication is an example of negative feedback, since the system returns to its original state.
False.
Eutrophication is an example of positive feedback, as each stage reinforces and worsens the next.
What is a dead zone?
A dead zone is an area of ocean or freshwater with insufficient oxygen to support aquatic life.
In the positive feedback cycle of eutrophication, decomposition of dead organisms releases more back into the water, promoting further algal growth.
In the positive feedback cycle of eutrophication, decomposition of dead organisms releases more nutrients back into the water, promoting further algal growth.
How can eutrophication affect a region's fisheries?
Eutrophication can cause fish kills and long-term reduced fish stocks due to low oxygen levels.
How can eutrophication affect human health?
Eutrophication can lead to harmful algal toxins and contamination of drinking water sources.
During eutrophication, dense growth of macrophytes such as duckweed and water hyacinth near the surface can block from reaching underwater plants.
During eutrophication, dense growth of macrophytes such as duckweed and water hyacinth near the surface can block sunlight from reaching underwater plants.
True or False?
Algal blooms and decaying algae can cause foam and a slimy water surface.
True.
Algal blooms and decaying organic matter contribute to unpleasant odours, foam and a slimy water surface.
What are the three main stages leading to the impact of a pollutant on the environment?
The three main stages are the human activity producing the pollutant, its release into the environment, and its impact on ecosystems.
Define buffer strips.
Buffer strips are areas of vegetation planted along waterways to absorb excess nutrients before they reach the water.
Define bioremediation.
Bioremediation is the use of living organisms to clean up contaminated soils and sediments.
How do slow-release fertilisers help reduce water pollution?
Slow-release fertilisers release nutrients gradually, reducing the amount of nitrate and phosphate leaching into water bodies.
How does crop rotation help reduce fertiliser-related water pollution?
Crop rotation improves soil health and fertility by alternating crops with different nutrient needs, reducing the need for chemical fertilisers.
What is the purpose of using phosphate-free detergents?
Phosphate-free detergents minimise the amount of phosphate pollution entering waterways.
What advanced methods can be used in wastewater treatment to remove nutrients before they reach natural waters?
Advanced wastewater treatment methods, such as constructed wetlands and biofilters, remove nutrients before they reach natural waters.
True or False?
Applying fertiliser during periods of heavy rain minimises nutrient run-off into water bodies.
False.
Fertiliser applications should avoid periods of heavy rain to minimise run-off into water bodies.
What is dredging used for in managing eutrophic lakes?
Dredging is used to remove nutrient-rich mud and sediments from eutrophic lakes.
How can ecosystem restoration help address water pollution?
Ecosystem restoration can involve reintroducing native plants and fish, and restoring wetlands to filter nutrients naturally.
Planting crops helps absorb excess nutrients and prevent soil erosion.
Planting cover crops helps absorb excess nutrients and prevent soil erosion.
True or False?
The three-level pollution management framework can only be applied to eutrophication, not to other types of pollution.
False.
The same framework can also be applied to other types of pollution, such as plastic and chemical pollution.
How can filtration and treatment systems help address chemical pollution?
Filtration and treatment systems can remove harmful chemicals from wastewater before it is released.
Using organic fertilisers, such as or manure, instead of synthetic fertilisers can help reduce water pollution at the source.
Using organic fertilisers, such as compost or manure, instead of synthetic fertilisers can help reduce water pollution at the source.
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