...
During Fall 2010 I have continued working on the Stacked Rapid Sand Filtration Team. In order to wrap up the summer proof-of-concept research, we as a team have made systematic physical observations of the filter backwashing back washing process in the clear filter column. We visually observed the backwashing back washing process in the filter both to confirm that the bed of a stacked filter could effectively be fluidized, and to develop a procedure for initializing and terminating the process. The backwashing back washing steps were varied and the observations were used to determine which method of backwashing back washing was most effective. We are close to finishing up We finished up a proof-of-concept paper explaining the concept of stacked rapid sand filtration, using the summer performance data and this semstersemester's backwash observations, to show that the technology is viable at the laboratory scale and to help put the technology out there. We have been running time-series and steady-state flow distribution tracer dye studies to determine whether flow in each layer of the filter is in fact uniform. These studies could help us determine how much of the sand bed is effectively being used. We . We have also been running filter performance studies similar to those that took place during the summer so as to better understand occurrences such as turbidity spikes that were observed during the summer and verify that we can get the same performance with a filter with six layers. We have also been working on: developing a full-scale filter design tool, applying to the EPA P3 sustainable design competition to fund future developments, and determining whether an underdrain system may be needed for the bench-scale stacked filter system. designing a full scale demonstration unit that we will bring along with us to Honduras in January.
In the near future we plan to: build a two 20 cm single layer control filter filters in order to compare upflow from downflow filtration performance , run filter performance studies similar to those that took place during the summer so as to better understand occurances such as turbidity spikes that were observed during the summerwith different inlet/outlet configurations, and possibly optimize the sand grain size of the filter media.