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The next order of business was performance testing. We added different concentrations of clay suspensions along with a constant coagulant dosage. We obtained a removal percentage of about 99%.
Spring 2013
Over winter break the low flow stacked rapid sand filter was taken to Honduras to be demonstrated. However, shortly after the filter was put to the test, it broke down due to the fragility of the manifolds. Thus, the next step was to redesign the slotted manifolds. Simultaneously, we realized that the Stacked Rapid Sand Filter had won the phase 1 part of the EPA P3 competition and that we had to present the filter at the phase 2 part of the competition in Washington DC in April. Consequently, we diverted our attention to writing the proposal for the filter and building a prototype of the filter which could be demonstrated at DC. Scaling down the filter was a major issue during construction. The finished product was 6 ft tall and 2 inches wide and worked well at the competition. We have yet to hear back from the EPA regarding the results, however, we did get second place for the ASCE Sustainable Development Award.
After returning from DC we finished the modifications to the slotted manifolds and we designed a sand drain. These are in the process of being implemented.