Barry W. Finger

Ersatz wastewater formulations for testing water recovery systems

This paper addresses the derivation of chemical ersatz recipes for use in the evaluation of development hardware designed for advanced spacecraft water recovery systems. The recipes simulate characteristics of wastewater generated on a transit mission and on an early planetary base (EPB). In addition, recipes are provided which simulate the water quality of the early planetary base wastewater as it moves through a combination biological and physical-chemical water recovery system. These ersatz are considered to be accurate representations of the wastewater as it passes through primary, secondary, and tertiary processing stages. The EPB ersatz formulas are based on chemical analyses of an integrated water recovery system performance test that was conducted over a period of one year. The major inorganic and organic chemical impurities in the raw wastewater, and in the effluent from the various subsystems, were identified and quantified. Procedures for preparation of ersatz are discussed in detail, and analyses techniques used for measuring the chemical species are presented.

Development of an Intermediate-Scale Aerobic Bioreactor to Regenerate Nutrients from Inedible Crop Residues

Three Intermediate-Scale Aerobic Bioreactors were designed, fabricated, and operated. They utilized mixed microbial communities to bio-degrade plant residues. The continuously stirred tank reactors operated at a working volume of 8 L, and the average oxygen mass transfer coefficient, k(sub L)a, was 0.01 s(exp -1). Mixing time was 35 s. An experiment using inedible wheat residues, a replenishment rate of 0.125/day, and a solids loading rate of 20 gdw/day yielded a 48% reduction in biomass. Bioreactor effluent was successfully used to regenerate a wheat hydroponic nutrient solution. Over 80% of available potassium, calcium, and other minerals were recovered and recycled in the 76-day wheat growth experiment.

Application of capillary fluid management techniques to the design of a phase separating microgravity bioreactor

Manned space missions require the development of compact, efficient, and reliable life support systems. A number of aqueous biological conversion processes are associated with bioregenerative life support systems. Vessels, or bioreactors, capable of supporting these processes in microgravity must be developed. An annular flow bioreactor has been conceived. It has the potential to incorporate containment, phase separation, gas exchange, and illumination into a single vessel. The bioreactor utilizes capillary fluid management techniques and is configured as a cylindrical tube in which a two-phase liquid-gas flow is maintained. Vanes placed around the inner perimeter enhance capillary forces and cause the liquid phase to attach and flow along the interior surface of the tube. No physical barrier is required to complete phase separation. It is shown analytically that liquid film thickness is limited only by vane geometry and that an annular flow bioreactor capable of managing 284 liters would occupy 0.7 cubic m, less than half the volume of a Spacelab experiment rack.

Biological Wastewater Processor Experiment Definition

INTRODUCTION The primary objective of the biological wastewater processor experiment definition NRA was to conduct preparatory ground-based research to enable development and optimization of future space flight experiments. Research tasks encompassed performing a comparative bioprocessor study to examine adaptation of existing bioprocessing technology for use in microgravity, microbiological consortium evaluation to characterize the bacteria used for degrading wastewater, bench-top testing to investigate surrogate parameters for monitoring bioprocessor performance, computer modeling to investigate start up of the reactors and scaling laws, and prototype infrastructure development to address form, fit and function requirements for designing a space flight-qualified payload.