I added this instructable to some contests. if you liked this project, please vote this
My answers to the Make-To-Learn contest:
What did you make?
I made a portable water purifier using some natural materials and a plastic bottle water flowed slowly, but gave a very good result the body is made of plastic bottle, cut and kept the top side upside down inside the other side. inside it consists 4 simple layers cotton, pebbles, gravel and sand, simulating the groundwater replenishment . the edges of the open side is covered with duct tape in order to prevent hazard.
How did you make it?
At the time I made this project, i didn't have any tools to make it, except my handy pocket knife and first aid kit in my bag. I just cut out the bottle into two, then found the pebbles, gravel and sand in the park, filled the dirty water and came the pure water on the other end,
and saved the day from the thirst. The ideas are basically from my science book and it's chapter about water.
Where did you make it?
I made it initially at a situation at the local park, but also used that project for my school's annual science fair, and it worked very well.
What did you learn?
I learnt mainly about replenishing the groundwater, its importance and it's practical use on our lives. It also gave a better insight of this topic. one of the challenges i met here was to layer everything evenly. i had to close the cap, layer up and then open up the cap for further purification. It gave me good grades too.