Purification and Analysis of Contaminated Water Using Slow Sand Filtration and Metal Ions

The intent of this research was to improve the efficiency of slow sand water filters at killing harmful pathogens and purifying water. Specifically, the main goals this summer were to find out how much copper sand would retain and to maximize it. Copper has been used as a germicide for centuries and has a lot of potential for helping to optimize water filters. Last summer’s research confirmed that copper could be retained by the sand in the water filters, this summer we measured how much was retained. A variety of different sands were soaked in an array of copper solutions in order to saturate the sand with copper. Afterwards the excess copper solution was poured off and the sand samples were dried. The amount of copper in each sample was measured using PIXE and the particle accelerator as well as atomic absorption. A 20% nitric acid solution was used to strip the copper out of the sand and diluted before being testing using atomic absorption. In addition, the residual time needed for the water to remain in the filters for purification was also tested. Miniature sand filters tested how much time the bacteria contaminated water needed to spend in the filter before sufficient cell death occurred from the presence of copper and lack of oxygen. The filters tested water that had residual times of 1 hour, 24 hours, 48 hours, and 72 hours. For each amount of time, there was a filter with copper present and one without