(64i) Purification and Analysis of Bacteria Contaminated Water Using Slow Sand Filtration and Metal Ions

The purpose of our research was to improve the efficiency of slow sand water filters. This technology is being used in undeveloped countries to provide cheap, clean drinking water to those who normally would not have it. Slow sand water filters were constructed out of PVC pipes and filled with varying types of layered sand. Each filter was testing the efficiency of one of four different types of sand or two forms of metal ions at killing bacteria. The efficiency was measured by comparing the concentration of fecal coliforms in the output water to that of the input water. These experiments were carried out at room temperature and 4^oC in order to observe the effect of temperature on slow sand water filtration. Most traditional water filters rely on a biofilm forming on top of the sand and a lack of oxygen in the column of sand to kill coliforms in the water. Our research added to this system by introducing copper as a germicide to the columns. We added copper sulfate or ACX (copper-zinc alloy) to some of the tubes and observed their bacteria killing efficiency compared to copper-less filters with the same sand type and temperature and used particle acceleration to determine which sands retained the most copper. We also tested bacteria concentrations and pH at varying heights on the column to determine where most of the cell death was taking place.