Brainstorming


 * __Water purifying__

Before we actually purify water in West Lake, we first have to measure how polluted the water is. We came up with several methods, which all the methods/idea came from what we studied in each subject of science we’re taking (Biology, Chemistry, ESS and Physics)
 * //Biology//**

We first came up with what we’ve done in V-resort trip, the lab we did in Biology “Determining Health of a River’. In this lab, we used 3 biotic indices to determine how clean the river near the V-resort was.

(1) __Simpson's Diversity Index__



(2) __EPT Richness -__ This stands for Ephemeroptera (Mayflies), Plecoptera (Stoneflies) & Tricoptera (Caddis flies). These are intolerant to pollution and their numbers drop very quickly when temperate waters are heated or polluted. We simply count the number of different species of these and apply this to the table below.



(3) __Pollution Tolerance Index (or PTI)__




 * //Chemistry//**

First we should check if the water in West Lake is polluted or not, or if it is polluted, then we should check how badly the pollution is. We can check this by measuring the pH of the water. If the pH is 7, then the water is neutral and not polluted. If it is less then 7, the water is acidic which is dangerous to living creatures of the West Lake. We can use a pH meter.

After collecting the sample of water, simply place the pH meter inside the water sample and a number will show on the screen of the meter.

__At the river__

I will collect a sample of the West Lake water by storing at least 250mL of the lake water in a plastic bottle, this sample should be more than enough to test the pH of the lake. To test the pH, i will use a pH meter. A value of 7 means the lake is at a stable condition, a value lower than 7 means it is acidic and needs to be purified. Researches will be done to determine the possible ways to purify lake water:


 * Reverse Osmosis
 * Distillation
 * Water purification systems

__Water pollution__

Water pollution is largely caused by human activities. Most of the time we see trash in polluted lakes. People even dispose of liquid into lakes such leftover juice when drinking while walking or food that dissolve once thrown into the lake. Because of this, lakes experience an increase in nutrients and becomes eutrophic. The increase in nutrients consist of an increase in nitrate and phosphate levels which bring negative impacts on water creatures such as fish, tadpoles, and water plants. Though the enrichment in nutrients does not sound any less positive for lakes, it results in water plants to grow extensively which allows the water to absorb less light. Not absorbing enough light leaves the water with bacteria which kills other water creatures such as fish and tadpoles.

Purifying water is important in ESS subject because water condition is very important in ecosystem. If the water gets polluted, (like if pH of water changes) then organisms living in that water will soon get affected by the condition of water. For example, number of phytoplankton will rapidly decrease and this will also cause population of upper food level/tropical level species to decrease. Change in condition of water might affect the whole food chain of the living organisms in that area.
 * //ESS//**

If your water becomes contaminated and you don't have bottle water, you can purify it in a few different ways. If it is cloudy, first filter it through clean cloths or allow it to settle and then pour off the clear water. Then, you can boil the water for one minute to kill most disease-causing organisms. You can also add one-eighth of a teaspoon of household chlorine bleach per gallon of water. You should double the amount if the water is discolored or murky. Stir and let it stand for 30 minutes. Chlorine bleach tablets are sold at camping supply stores to purify water for drinking. You can also use five drops of iodine per gallon to disinfect water. Store boiled or disinfected water in clean, covered containers. If the boiled water tastes too flat or the chlorine taste is too strong, pour it from one container into another.

Find the speed of polluted water and purified water.
 * //Physics//**

For physics, we can test how water purifying has improved the speeds of the water surface, because when the water is cleaner. Maybe the currents may improve in speed because there is less for the current to move through and carry. We can test the water currents in the same area after purifying and before and compare the results. [written by Minh Vo, difficulty with editing wiki]