String Digester - Fall 2018

Rosalie Krasnoff, Zsofia Szegletes, Madeline Garell, Antonio Martinez

ABSTRACT:

The string digester team’s objective for the Fall 2018 semester was to continue research on designing a new wastewater treatment system to eliminate problems associated with current trickling filters. To improve consistency in wastewater treatment, experiments were conducted using strings to optimize surface area. 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. Initial tests involving different string materials, biofilm growth, and string spacing helped define design parameters for the construction of a functioning string digester.

Trickling Filter - Spring 2018

String Digester — Jillian Whiting, Ben Gassaway, Rosie Krasnoff

ABSTRACT:

The trickling filter subteam's objective for this semester was to identify problems with trickling filters and to provide possible solutions to these problems. The long term goal of the team is to create a novel design for a trickling filter that will perform secondary and tertiary treatment on domestic wastewater in a future AguaClara wastewater treatment plant. After an extensive literature review, two bench scale experiments were conducted. The first test aimed to characterize the hydraulic behavior of a trickling filter and the flow of water through its packing media. The team used this information to identify the areas within the system with the greatest potential for improvements. From this information, the first prototype was built using strings to control flow paths and create a high surface area to volume ratio. Preliminary tests were conducted on the prototype to determine flow dispersion, residence time, and optimal string spacing.

String Digester - Spring 2019

Kiki Lo, Antonio Martinez, Gaby Sibel, Zsofia Szegletes

ABSTRACT:

The objective of String Digester for the Spring 2019 semester was to continue research on revamping a wastewater treatment system to eliminate problems associated with current trickling filters. To improve consistency in wastewater treatment, experiments were conducted using metallic and plastic chains to optimize surface area. 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. These tests involved testing different chain types and synthetic materials for their hydrophilic properties, fabricating and testing reactors for efficiency, and researching biofilm growth to help define design parameters for the construction of a functioning string digester.

String Digester - Summer 2019

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.