ess 4.4 water pollution test

Water pollution

the addition of any substance that decreases water quality

2 main type of pollutant

used to be waste water, now its agricultural pollution/fertilizers

how to measure waste water

using the BOD

non-point source pollution

water pollution that does not have a specific point of origin for example all of the farmer fields in an area

what results from algae blooms

when the algae die, the same decomposers are gonna break it down, and as they do that, they are pulling oxygen out of the water and so we are producing dead zones by pulling the oxygen out of the water and killing fish and other organisms.

describe the process of eutrophication

Nitrates and phosphates are the inputs for eutrophication. When Nitrates and phosphates are added to bodies of water, they cause accelerated growth due to all their nutrients. This causes algae blooms which blocks sunlight entering the water, and with the increased algae, the demand for oxygen increases, this leaving not enough oxygen for other organisms such as fish. This begins a positive feedback loop, in which the fish will begin to die and fall to the bottom of a lake, while the bacteria decomposes the dead fish, they will use up more oxygen, and the dead fish will release more nutrients, which will cause further growth of algae blooms. Eventually, there will be a point where there is too much competition, and algae will begin to block their own sunlight and will reach a tipping point, eventually dying and fall to the bottom of a lake, at which point the entire body of water will be dead.

waste water pollution

animal and human waste (biggest type of pollution) the waste has to be broken down generally using bacteria. as the bacteria breakdown the waste they require oxygen to do that. we can measure how polluted the water is using the biochemical oxygen demand, which looks at how much oxygen these bacteria are requiring. as the bacteria do this they pull oxygen out of the surrounding material, and can lead to dead zones and increase nutrients, resulting in eutrophication, and algae blooms. Wastewater carries desease such as collara from one area to another.

natural eutrophication

over hundreds or thousands of years, ponds and lakes are gradually enriched with nutrients through the falling of leafs etc

3 types of water pollution

1. point source 2. non point source 3. groundwater pollution

how do we categorize water pollution

depending on where the pollution is coming from

Point source pollution

pollution that comes from a specific site (coming out of one pipe or one ship)

example of a dead zone.

Gulf of Mexico

indicator species

there are many diseases that can be found it water so scientists use an indicator species, and we can see that if the indicator species is found in the water then other diseases will be found as well.

groundwater pollution

underneath the ground itself. hard to track because there is no easy way to tell where the polluted water came from

three steps of stopping pollution

1. Altering human activity that is producing pollution in the first place. 2. controlling release of pollutant (through legislation, Clean Water Act etc.) 3. clean up and restoration of damaged systems

Eutrophication

A process by which nutrients, particularly phosphates and nitrates, become highly concentrated in a body of water, leading to increased growth of organisms such as algae

Biochemical oxygen demand (BOD)

Biochemical oxygen demand (BOD) is a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity. BOD is used to indirectly measure the amount of organic matter within a sample.

India case study

Ganges river in India is one of the most polluted in the world, part of this is down to the fertilizers being used in the surrounding area contaminating the water causing eutrophication which causes the ecosystem to be less resilient.