Clean Water From Sand And Sugar
Run Lin (Mark) Xiao, Alan Zhou
David Thompson Secondary
Floor Location : J 141 N

The goal of this project was to design a "super material" that would effectively filter contaminated water and would require few resources to create.

The initial idea was to remodel a conventional water filter that used activated carbon as its main source of particle filtration. After testing some of these filters for effectiveness, it was decided to compare it against something more inferior in terms of filtering abilities like sand. After sanitizing it, it was found that the water filtered by the sand did not differ much in terms of ppm compared to the carbon. Obviously, the volume of the respective materials varied (more sand was used than carbon in these tests), but this revelation sparked an idea, leading to the creation of a carbon covered sand using sugar. However, it was decided the material could be improved even more.

It was found that graphene, a one-atom-thick layer of carbon bonds, had a very densely packed infrastructure of atoms, and would therefore make a great filtering material to bond to the sand. The large surface area of graphene made it more effective at trapping biological contaminants. The material was also relatively easy to make; it was, after all, just sand coated in a sheet of carbon atoms with strong double-bonds. Using the high temperature capabilities of a kiln, the silicon dioxide (sand) was catalyzed[1] with the carbon, creating a graphite-coated sand. However, a reducing and chemically inert (non-reactive) atmosphere was needed for the graphene to form. Using a ceramic separator and a layer of activated carbon powder, this was somewhat achieved.

The sand was then treated with a 1M sulfuric acid to “activate it”, creating divots for more surface area. The result was a black powder that was able to filter impurities from water extremely efficiently. The ppm measurements in water filtered by our control sand and the water filtered by the variable sand were compared, and it was found that the variable was almost 10 times more efficient. This sand was then named the Graphene-sand Composite (GSC).

The GSC was then fitted into an ABS pipe (15 mm long, 3.7 mm wide). The pipe was then sealed on both ends with polyester fabric and Duct tape.