Group 7
Samantha Poh
Loke Xin Xun
Sean Lee
Shi Jian Jiang
PHOTOS ARE FOUND AT THE BOTTOM OF THE POST. Thanks.
Geography
Causes of pollution are:
1. Dumping toxic waste into rivers causes organisms residing in the rivers to become poisoned and die.
2. Waste that does not dissolve will block out the sunlight from reaching the plants that grow below the water surface, preventing them from photosynthesizing and plastic bags can trap fishes and other animals in the water.
this also increases the turbidity of the water, and trapping heat in the river, causing the temperatures to rise and the amount of dissolved oxygen in the water will decrease and kill life forms.
3. Motor vehicle emissions and coal-powered stations are leading causes of air pollution, their emissions polluting the atmosphere with harmful chemicals. Carbon dioxide acidifies the ocean, the ongoing disease lowering the pH value of the oceans as it dissolves.
Consequences of pollution are:
1. Poisoned fish are eaten by larger fish, and in some cases the larger fish are fish we consume. thus the poison gets transferred to us and we get sick.
2. Oil spills can cause skin rashes and irritations.
3. Radioactive substances can cause cancer as well as birth defects.
4. Air pollution can cause respiratory diseases, cardiovascular diseases, chest pain, etcetera.
5. Smog and haze caused by forest fires can block out the sun, preventing the plants from photosynthesizing.
6. Soil can become infertile for plants and affect the food web.
We have studied Kallang River and Jurong Lake and can conclude that Jurong Lake is far less polluted than Kallang Lake. It was thriving with life. There were snail shells in the drain, dragonflies on the river banks and some small fish (about this size <-->). The soil was fairly fertile, with lots of trees and grass. The water was a clean turquoise colour with no litter floating about. On the other hand, Kallang River's water was a murky brown, and plastic bags were seen on the banks and in the water. There were some snail eggs and small critters, but not much. Kallang River is the venue for many recreational water sports such as kayaking and dragon boating. There were rocks of all shapes and sizes on the banks. There were some shells lying in the sand. The grass was barely a scrub.
Keeping rivers clean
1. Dispose of hazardous household products correctly. Paints, insecticide, cleaning solvents, etcetera should be kept away from drains, sinks and toilets. They can contain poisonous chemicals that can end up in water bodies.
2. Conserve water. 73 percent of the water used at home are flushed down the toilet and washed down the shower drain. Toilet dams and bricks placed in the toilet tank can save up to four gallons per flush. Low-flow flushes and showerheads save a lot of water. Sweep driveways and sidewalks instead of hosing them down.
3. Use natural fertilizers like compost, manure, etcetera. Composting setups decrease the need for fertilizer and helps retain soil moisture.
NOTE: The images used below are from Google.
Science
Background Information
Kallang River: Venue for many recreational water sports such as kayaking and dragon boating
Jurong Lake: Cleaner water, no litter, lots of trees and plants
Hypothesis
Based on looking at the 2 rivers, our hypothesis is this:
Kallang River is more polluted than Jurong Lake.
Determining Variables
For a fair test, only one variable must be changed. Our changed variable is the water body. We are using Kallang River and Jurong Lake. We have to take the data of the water bodies and analyse them. Our MGA sensors at our disposal are the temperature sensor and pH sensor. The dependent variable is the result, which is the pH level and temperature of the water bodies. The controlled variable is the amount of water taken.
Methodology
1. Go to Kallang River.
2. Take 200ml of water from it.
3. Plug in the 2 sensors and take the air temperature and pH level three times.
4. Take the water temperature 3 times.
5. Be sure to record everything down in the UBD booklet.
6. Use a cotton bud and dip it in the water.
7. Swab half of the petri dish with it.
8. Close it quickly.
9. Go to Jurong Lake and repeat steps 2-8 there.
Results
KALLANG RIVER
Air temperature(degrees Celsius) - 31.7, 29.9, 30,1. Average: 30.56
Water temperature(degrees Celsius) - 31.7,31.9, 32.2. Average: 31.93
pH - 9.2,9.4,9.5. Average: 9.36
JURONG LAKE
Air temperature(degrees Celsius) - 30.1, 30.5, 30.7. Average: 30.43
Water temperature(degrees Celsius) - 30.3, 30.2, 30.2. Average: 30.23
pH - 7.5, 7.5, 7.5 Average: 7.5
Discussion
Air temperature: From the readings, Jurong Lake is cooler than Kallang River.
Water temperature: Based on our measurements, Jurong Lake is yet again cooler than Kallang River. Its temperature falls in the "Good" category in water quality. It is safe to say that its turbidity is quite low, and there is a fair amount of dissolved oxygen. Kallang River's readings show signs of pollution as its reading falls under the "Polluted" category in water quality. The turbidity may be higher and there may be less dissolved oxygen in the water.
pH: Kallang River's pH is highly alkaline, which is probably due to industrial waste released into the river. It will cause the death of most life forms. Jurong Lake's pH level is 7.5, almost neutral. The water quality is good and the effect is optimum growth and health for most aquatic organisms.
Conclusion
JURONG LAKE IS LESS POLLUTED THAN KALLANG RIVER.
Evaluation
The results of the bacteria growth on our petri dishes were inaccurate due to an error made during the swabbing, which could be that the petri dish was left open for too long and bacteria from the surrounding air entered.
