The Spring 2011 Stock Tank Mixing Team is working to improve the current stock tank mixing system that is currently being implemented in Honduran AguaClara plants. The primary purpose of this team is to ensure that the chemical dose controller is always receiving the same concentration of coagulant. It is part of the team's responsibility is to research the properties of aluminum sulfate (alum) and polyaluminum chloride (PACl) coagulants such as density and dissolution properties. The team has thus far conducted alum experiments such as the "double bucket" idea and the "upflow" experiments to find ways to completely dissolve the alum. For PACl, the team is experimenting with homogeneous mixing and uses the "worst case scenario" setup to conduct experiments. We have quantified the inefficiency of stick ("simple stirrer") mixing and have developed the centrifugal pump mixer as a possible future mixer for AguaClara plants. | 