Seawater pollution

[RBST]

Hello,

I'm trying to design an experiment to test for water pollution.

I need some ideas about what to test for and how.

any ideas?

[x___x]

Hey, we did an experiment on a similar topic.

Here is this simple idea:

Investigate the effect of hot water as a pollutant to the marine life.

The fact that hot water has less oxygen concentrations than cold water is the basis of this experiment. So basically, you have to use an oxygen sensor along with a data logging software in order to measure the amount of oxygen in a hot sample of water and a cold sample of water. The hot water sample can be taken from the water dumped by factories, and the cold water sample can be taken from anywhere in the sea.

Another idea (this idea is from my head, so I don't guarantee that it will work):

You can take two dishes of sea water. Leave one of them as it is, and spill some pollutant in the other dish (for example gasoline or petrol). Since gasoline has a lower density than pure water, let alone salty sea water (which is denser), the gasoline will float to the surface of the water forming some kind of a blanket. This blanket would not allow enough carbon dioxide to be recycled into the system.

So in order to prove that the gasoline acts as a pollutant and does not allow carbon dioxide to be recycled into the second dish, you need to put an aquatic plant into both dishes (something like Elodea will be fine_ not sure though that this plant can tolerate salty mediums. ask your teacher). Those aquatic plants would take in carbon dioxide for photosynthesis, thus decreasing the overall amount of CO2 inside the water. In case of the first dish, where there is no gasoline blanket to prevent CO2 from entering the system, CO2 in the air should be able to dissolve into the water, thus renewing the source of CO2. On the other hand, the second dish where there is a blanket of gasoline, which prevents CO2 from reaching the water, there would be no renewal in the dissolved CO2 supply. Thus, soon the amount of CO2 dissolved would perish, leaving the aquatic plant no CO2 for photosynthesis.

The amounts of CO2 at the beginning and the end of the experiment can be measured using a CO2 sensor at a certain pressure and temperature; these two should be the same (constant) for both dishes.

HTH

Good luck.

&&, You're from Qatar, which school are you attending?

[RBST]

The first idea is a good one i guess, and easy as well!

The second one is useful to prove that gasoline is a pollutant. What I'm doing is that I'm going to take different samples from different parts (one from the coasts of a village called Umm Salal Ali and one that's in RasLaffan next to QatarGas)and "hopefully" show that the one next to the refinery is more polluted.

Thx a lot

I go to AJA, what about you?

Edited June 23, 2010 by RBST

[x___x]

I am a student in AlBayan School, or should i say was?

i just finished high school ;p

nice talking to a fellow IB student from the same country

[sweetnsimple786]

You can also look at the organisms that live in the waters, if the waters are comparable. In the healthier waters, you'll find organisms that are more sensitive to the specific conditions of the waters. In polluted waters, you typically find organisms that can survive pollution, and the sensitive ones have already gone away and/or died. Here's Wiki's thoughts on Bioindicators.

Maybe you also want to look at pH levels. [pollution related to acid rain, not necessarily gasoline] Perhaps the one near the refinery is polluted, but maybe the one off the coast of the village is polluted in a different way.

[RBST]

Acidity is a good point!

Do you know if salinity has anything to do with pollution? I'll check to compare it with the optimum salinity, this might be useful.

Thx sweetandsimple

[sweetnsimple786]

I'm sure you can Google it and find something better than I did.

http://www.tececo.com.au/sustainability.salinity_pollution.php

Our reading of the current literature indicates a failure to understand the water dynamic. Salinity and pollution are connected by a fundamental truism that does not seem to emerge in the literature which is that the more water travels through ground - the more salt it picks up as it will dissolve anything that is soluble and salts are by definition soluble. The more it travels through built up areas the more soluble pollution it can gather. The faster it travels the more energy it has to carry mud, silt and and macro pollution. Because they are controlled by the same water dynamic we discuss salinity and pollution together in this section.

I didn't realize the point it's making. I thought of higher/lower salinity as a threat to the organisms living there because they have to expend greater energy to have the optimal salinity level in their bodies, which they aren't adapted for, like freshwater and marine fishes can't exchange habits.

Read the rest of the site because it has good information.

And no problem. =)

[RBST]

Thank you for the link, it' very useful