chapter 4.4 Flashcards
water pollution
Define Water Pollution
Water pollution is the contamination of bodies of water by pollutants either directly or indirectly.
What are the types of water pollutants?
Anthropogenic : Water pollution caused by humans
Point Source or Non Point Source (singular source or multiple/large area of sources)
Organic or Inorganic
Sources of Freshwater Pollution
Agricultural run off
Sewage
Industrial Discharge
Solid Domestic Waste
Sources of Marine Pollution
Rivers
Pipelines
The atmosphere
Human activities at sea (operational + accidental)
What is Floating Debris
Floating debris is waste that floats on the surface of water.
Refer to slide no. 118 to 124
What are the issues of ocean plastics and microplastics? (Any 2)
Larger Pieces Entangle Sea Mammals and Fish
Chemical Contaminants of microplastics can be endocrine disruptors
Filter feeders ingest microplastics
Human eat marine organisms and therefore accumulate microplastics
Where does this plastic come from? Any 3 examples.
- Ocean based activites such as fishing and aquaculture.
- Urban areas
- Littering
- Poor waste disposal
- illegal dumping
- Construction Industry
- Microbeads
What are the management solutions of water pollution (2 International and 2 individual level)
International legislative frameworks : International legislative frameworks should be strengthened or at least adhered to.
Producer responsibility : putting the responsibility of finding sustainable alternatives to plastics to producers of plastic.
R&D : if more research and development for sustainable alternatives of plastic are done which make it biodegradable and less of a biohazard, then it will be beneficial. Here, additional funding is also required.
Some other actions we can take on an individual level are
Make less use of products which have plastics
Thrift
Use reusable bags
Stop buying plastic-packaged snacks and buy larger packs, store in containers.
Participate in clean-up projects
Measuring water pollution (test)
- pH
- Nitrates or Ammonia
- Dissolved Oxygen (DO)
- Conductivitiy
- Turbidity
- Fecal Coliform Test
Define Biochemical Oxygen Demand
The amount of oxdygen utilised by aerobic organisms to break down organic matter/waste in a given volume of water, at a certain temperature over a certain period of time.
Define Eutrophication
Eutrophication is when excess nutrients are added to an aquatic ecosystem. Is phosphate or nitrate concentrations have previously been limited, then algal blooms may develop with the extra nutrients.
How to measure BOD
Take a sample of water at a measured volume
Measure the oxygen level
Keep the sample in a dark place at 20*C for 5 days
After 5 days re-measure the oxygen level
BOD is the difference between the two measurements.
What does this mean?
High BOD means : many organisms using oxygen for respiration
Low BOD means : Relatively few organisms needing oxygen for respiration
High BOD & Low DO - high pollutant levels
Low BOD and High DO - low pollutant levels.
Explain the process of eutrophication
- Fertilizers wash into a river or lake
- High levels of phosphate in the water allow algae to grow faster
- Algal blooms (mats of algae) form, blocking light for underwater plants, which die.
- More algae means more food for zooplanktons and small animals that feed on them. These are food for which fish multiply, as there is more food. Therefore, there are then fewer zooplankton to eat the algae.
- Algae die and are decomposed by aerobic bacteria.
- These bacterias have a high BOD (more oxygen required, since lot of algae) and thus everything dies as food chain collapses.
- Oxygen levels fall lower
8.Dead organic material forms sediments on the lake or riverbed and turbidity increases. - Eventually all life is gone and the sediment settles to leave a clear blue lake.
What are the effects caused by eutrophication?
- Species diversity decreases
- Plant and animal biomass increases
- Turbidity increases
- Anoxic conditions may develop (less/no oxygen)
- Reduction in the length of food chain
What are marine dead zones?
Zones that are poorly oxygenated in the world’s seas and oceans.
