Preliminary Design Considerations on Biological Treatment Alternatives for a Simulated Mars Base Wastewater Treatment System

The Mars Society has been preparing designs for a terrestrial-based analog human habitat to research technologies suitable for extended human duration on Mars. The Mars Society's Arctic Research Station, currently in the design phase, is planned for habitation in summer of 2001 on Devon Island in northern Canada. An important component of the station will be the waste treatment and resource recovery system. The four to six people inhabiting the station in the summer months will produce both gray water and domestic sewage that requires treatment. The arctic environment of the planned location of the station imposes design constraints similar to those on Mars, affecting size, cost, reliability, and other critical considerations of the waste treatment system design. The focus of this paper is on the treatment of the wastewater, but the ultimate design for the station-and for human Mars missions in general-will need to be multipurpose with considerations of water recycling, nutrient recycling, and food production. The literature on available waste treatment alternatives is reviewed, including conventional physico-chemical treatment, microbial reactors, algal turf scrubbers, and treatment wetlands. A qualitative analysis is made of the relative qualities of these systems to assist in the choice of designs for the station. Two complex biologically based systems-algal turf scrubbers and treatment wetlands-are selected for more in-depth engineering analysis, with preliminary calculations for scaling to a six-man crew.