Tony Rector

Design and Preliminary Evaluation of a Novel Gravity Independent Rotating Biological Membrane Reactor

The integration of membrane-aeration technology with biological water processors has direct application to wastewater treatment in microgravity because of the ability to diffuse gases across the membrane without two-phase interactions (gas-liquid). Membrane-aeration bioreactors have demonstrated the ability to deliver a terminal electron acceptor (O 2 ) and substrates (CH 4 and H 2 ) to biofilms attached to the membrane surface. However, the process performance of these systems has been limited by mass transfer constraints. A novel bubbleless membrane-aeration bioreactor was design and tested at Kennedy Space Center. The Aerobic Rotational Membrane System (ARMS) consists of a rotational membrane module inside of a pressurized reactor vessel. Rotation of the membrane module enables a reduction in the mass transfer resistance coefficients associated with both the membrane/liquid boundary layer (k La ) and constituents in the bulk liquid, and it equalizes the concentration gradient across the bioreactor allowing for uniform biofilm formation and decreased bulk liquid O 2 transfer. Preliminary engineering tests have been conducted to determine the effect of key operational parameters (i.e. rotational speed, superficial velocity) on O 2 flux rates and hydrodynamic characteristics within the ARMS. This paper presents the ARMS design and results of the preliminary engineering tests.

Performance of the Extravehicular Mobility Unit (EMU) Airlock Coolant Loop Remediation (A/L CLR) Hardware

An EMU water processing kit (Airlock Coolant Loop Recovery A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of postflight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives was implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit components, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements. The intent of this paper is to summarize the findings of that evaluation, and to outline updated schedules for A/L CLR use and component life.