Madeline Garrell, Emily Wood
Abstract:
The String Digester Summer 2019 subteam continued research on designing a new trickling filter to eliminate problems associated with conventional designs. Experiments this summer focused on designing a water distribution system that does not encourage preferential flow, and creating a matrix of strings using "loopy yarn" as the filter media. An ideal string digester would distribute water uniformly onto a large number of densely packed strings from a spray. Initial testing demonstrated that a "good" spray can be achieved with flow rates on the order of 10 μL/s, which is the amount needed to ensure proper cleaning by a biofilm. Initial testing found the string density resulting in the least preferential flow to be between 25 and 30 strings/cm, although more trials are needed to confirm this result. Further experimentation is also needed to improve the spray pattern geometry, and to determine if the "loopy yarn" is suitable for biofilm growth. The long-term goal of this team is to create an efficient wastewater treatment system that will perform secondary and tertiary treatment on domestic wastewater.
