Preliminary Design Considerations For The M.A.R.S. Wastewater Treatment System: Physico-Chemical Or Living Machine?
David M. Blersch, Erik Biermann, and Patrick Kangas, Ph.D.
University of Maryland
As the Mars Arctic Research Station (MARS) moves into the design phase, a major component will be the development of the wastewater treatment system for both gray water and domestic sewage. Unique design constraints are imposed by the external environment and purpose of the MARS, affecting size, cost, reliability, and other critical features of the waste treatment system. Although the focus of this paper is on the wastewater treatment, the ultimate design for MARS will need to be multi-purpose, with considerations of water recycling, nutrient recycling, and food production. To begin the design process, it is important to review alternative treatment systems that are available. The literature on alternative systems is reviewed, including conventional physico-chemical treatment, microbial reactors, algael turf scrubbers, living machines, treatment wetlands, and partial closed ecological life support systems (CELSS). An analysis is made of the relative qualities of these systems to assist in the choice of designs for Mars and MARS. Some systems (e.g. conventional physico-chemical) serve only the purpose of waste treatment, while other systems (e.g. living machines) have the potential for multiple functions. Two of these systems (algael turf and living machines) were selected for more in-depth engineering analysis, with calculations of sizing and cost. Ultimately, the selected design will probably be a modular system with units hooked up in both series for progressive stepwise treatment, and in parallel for replication and reseeding capabilities. Finally, consideration is given to adapting Arctic species (mosses, lichens, and other herbaceous species) to the living treatment systems to enhance performance in a colder, low-light environment.