Marine Oil Pollution and Clean Up:
I bought some sand from Home Depot. I used a plastic box, shoe box and filled with the sand sliding from top to bottom. I created blue water using water and blue colored ink. It turned out as a good Ocean model. All the kids were watching with full curiosity. I made an 'Oil Barge' with simple small candle light stand on small ship shaped wooden plank which I got from 'Michaels' store. I used left over cooking oil (which I take to recycling center) and colored it with some black color. That cooking oil now looked like crude oil and I poured them in the candle stand tanks of my oil barge model. It was floating in my clean Ocean model.
All of sudden, I turned barge and oil fell into the Ocean and spread. I heard a big 'oooh' sound from the kids. I had made oil containers to contain oil spread using left over 'felt' and threw them around the oil polluted area. It contained the oil spread. I used cotton to absorb the oil and make my Ocean model once again a clean environment. I took some marine animal toys including a pelican toy and covered them with oil and taught them how to clean the oil soaked animals with dilute soap solution and dry them with towel. I told them to visualize the whole thing in real world and showed the pictures. All of them clearly understood how oil pollution occurs and how it can be cleaned.
Good Sample Identification:
Before going to teach in, I made three solutions - Solution A - Vinegar, Solution B - Baking soda solution and C - Filtered water. I bought pH paper from 'Amazon.com'. I told them there is a site where people are affected from a natural disaster and they don’t know which water they could drink. They send us three samples and asked us to find which sample can be used as drinking water. Kids used their school tap water (filtered using Brita water filter) as control and using pH paper they found that Solution A was an Acid, B - was a base and C was drinkable water. They were happy to find out the drinkable water and to know they have saved people from drinking the wrong water.
I felt this was a good small experiment to kids to identify the toxicity, which I fully used in my PhD research.
Water treatment:
I procured some Alum from 'Amazon.com'. I took some tap water and added some dirt solids and made a polluted water sample. Now added the alum and did some swirling (to give centrifugal force) and allowed that bottle content to settle. After few minutes the solids settled down and the above water as clean as we mixed the dirt before. I told them this is one of the steps how they treat water before it comes through the tap. Along with this primary (Physical) treatment, they also do secondary (biological) treatment and tertiary (Chemical) treatment.
Aquatic Biosphere:
I had collected some aquatic plants and water from our community pond. I used a clean glass bottle and added some filtered water. Then I added the pond water. That’s when I noticed some small water bugs were also in the pond water. The children were happy to see the bugs. I added some of aquatic plants in the water and closed the bottle and told them to keep it near a corner in the table and watch the bottle. The bugs were happily swimming in the water. After a week I will bring it back and let them in the community Pond again. I told them in future (several years) if we don’t reduce pollution, the future generations should have to live in contained self-sustainable biospheres and this bottle aquatic biosphere is one such example.
Safety:
I emphasized that in labs - safety is important. There may be several chemicals and biological organisms. So it is very important to follow safety procedures such as wearing lab coat, gloves, safety eye glasses and sometimes even mask. I used all these and showed them how the experiments are conducted in a real lab.
Renewable and Biodegradable:
I talked about Natural Renewable energies such as SOLARand WIND . Also I talked about Biodegradable materials. I showed models of them.
Finally, I told them how they can save the earth by using the paper they write fully instead of writing one line and throw. I told them about Reduce, Reuse and Recycle - Three R's. Also, told them not to waste water. In US, we are privileged to have water coming to us, but in some parts of the world to get water they have to travel so much. They really understood and were happy to be part of people, who would save the Earth, Environment and its Nature. These wonderful gifted and knowledgeable kids send me individual hand made cards to thank me for teaching them Environmental Sciences. It was a fulfilling day for me.
