Browsing by Author "Beitle, Eric"

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Analysis of CDC Bioreactor Internal Thermal Measurements and Sample Coupon Temperatures
(2023 International Conference on Environmental Systems, 2023-07-16) Beitle, Eric; Murphy, Connor; Velez Justiniano, Yo-Ann; Goeres, Darla
The Center for Disease Control and Prevention (CDC) bioreactor is an integral laboratory tool for the Environmental Control and Life Support Systems (ECLSS) biofilm formation and growth research program. Critical to this research is the need to adjust and maintain various surface temperatures of the coupons housed within the CDC Bioreactor. The purpose of this study was to provide quantitative temperature gradient information when the CDC Bioreactor was operating according to several process scenarios. Two primary process parameters were evaluated. For the first set of test parameters, the liquid level was maintained at 350 mL, with an inlet flowrate of 0.1 mL/min, 1 mL/min, 10 mL/min. The liquid was allowed to gravity drain out of the outlet spout. For the second set of test parameters, the liquid level within the reactor was maintained at 550 mL, with an inlet flow of 0.1 mL/min, 1 mL/min, 10mL/min and draining intermittently controlled to 0.8 mL/min to maintain the 550 mL level. Due to the placement of the thermocouple in the reactor, a difference in temperature occurred between the coupon surfaces and target Bioreactor temperature when operated according to the first set of test parameters. When the reactor was operated according to the second set of parameters, which resulted in the thermocouple being submerged, the temperature gradient was eliminated. The results demonstrated minimal temperature gradient between the top and bottom coupon surfaces for coupons placed in a single rod within the CDC Bioreactor for both sets of test parameters evaluated. The collection of this information helped to explain previous ECLSS biofilm formation test runs, along with providing guidance on best operating practices for future ECLSS experiments. The placement of the thermocouple also helps to explain the challenge of achieving and maintaining bulk liquid temperatures when biofilm is grown according to the standardized methods.
CDC Bioreactor Configuration Method for Volume Level Control with Controlled Inlet and Outlet Flow
(2023 International Conference on Environmental Systems, 2023-07-16) Murphy, Connor; Beitle, Eric; Velez Justiniano, Yo-Ann
Environmental Control Life Support Systems and other microbiological biofilm studies often utilize small scale bioreactors. Among these options are the popular BioSurface CDC bioreactors, currently being utilized by Marshall Space Flight Center groups researching the impact of biofilms on life support systems. After a recent experimental regime, it was determined additional equipment could be added to augment the capabilities of the bioreactors. Previous research configurations such as ASTM E3161 – 18 relied on an outlet stream gravity draining from a side drain port located above sampling coupons. This limited applications to experimental conditions with a controlled inlet and uncontrolled outlet flow. With the introduction of a small single pole single throw (SPST) reed float switch, a peristaltic pump connected to the outlet drain and a chassis controller, the bioreactor is able to maintain a set level. The modification allows additional variables to be tested, including highly adjustable fill and flush cycles, bioreactor volume, draining and filling control. Once the configuration modifications were implemented through the installation of the new equipment, data was collected to ensure the stability of the level measurements. As the level control switch is a float switch, consideration was taken into account for effects of internal stirring speed, along with effects of inlet and outlet flow rate. Data presented in this study will illustrate the stability and effectiveness of the configuration changes in equipment made to the bioreactor. These configuration changes are proving an effective control method to conduct biofilm mitigation techniques for ECLSS hardware research. The controlled level capabilities allow for a constant drip feed flow rate into the bioreactors, a key aspect of the biofilm mitigation testing.
Ground Test Validations for Uncrewed Dormancy Preparation and Recovery
(2024 International Conference on Environmnetal Systems, 2024-07-21) Beitle, Eric; McCormick, Robert; McCall, Shannon; Sandvik, Elizabeth; Velez Justiniano, Yo-Ann; Williamson, Jill
In future long-duration space flight and habitation missions, periods of uncrewed dormancy where life support systems are shutdown or in low power modes will occur. To examine the impacts of these dormant periods in water recycling systems, along with potential pre- and post-dormancy procedures, Marshall Space Flight Center has been building up an uncrewed dormancy test stand. The uncrewed dormancy test stand will include a urine separator from the Universal Waste Management System, a condensate separator, urine filter, brine filter and distillate filter. In conjunction to the test stand, the Center for Biofilm Engineering has been comparing effects of simulated shutdown procedures on microbial survival and material compatibility during dormancy and regrowth when systems resume operation. This publication will serve as an update on the test stand construction, including a description of the current lower fidelity versions of the urine and condensate separators being produced. It will also examine dormancy work being conducted by CBE and discuss how this may factor into procedures tested on the uncrewed dormancy test stand.
Status of ISS Biofilm Management Testing for the Water Processor Assembly
(2023 International Conference on Environmental Systems, 2023-07-16) Velez Justiniano, Yo-Ann; Murphy, Connor P.; Beitle, Eric; Cioanta, Iulian; Jackson, John; McGhin, Cary
Update to Developing a Multi-bioreactor Test Stand for the Evaluation of Biofilm Mitigation Technologies
(2024 International Conference on Environmnetal Systems, 2024-07-21) Beitle, Eric; Murphy, Connor; Velez Justiniano, Yo-Ann
Biofilm formation in spacecraft wastewater systems is a complex and impactful problem. Biomass flowing in these wastewater systems can cause clogging, higher differential pressures, and flow restrictions impacting equipment reliability and function. To explore this issue, the Marshall Space Flight Center's biofilm test stand was created and has been utilized to examine multiple biofilm mitigation techniques over a long duration test time. This paper is an update to a previous paper, ICES-2021-122, and will serve to discuss the modifications and enhancements to the biofilm test stand. While the previous configuration tested heat treatments and coatings, this phase of testing will examine differing materials, competing bacteria provided by an external bioreactor, a prototype phytoremediation unit, and additional testing with a nutrient filter. Configuration changes include the addition of float switches, adjustment of the drain assembly architecture and additional support hardware for the competing bacteria bioreactor and phytoremediation units.