Waste water treatment
Waste water treatment facilities are an essential requirement for a Martian settlement. A number of treatment processes may be required, depending on the contaminants present in the water. Waste water treatment facilities are very similar to Potable water treatment facilities, but treat more heavily contaminated water. In a closed loop system, the cleaned waste water is returned to the potable water treatment system for re-use. The water distribution system links the two ends of the water infrastructure. In an open system, the water is returned to the Martian environment, possible after some treatment if a biological containment planetary protection protocol is in place.
Waste water facilities produce cleaned water and sludge, the materials extracted from the water. Sludge can include active bacteria, sand, various salts and particles. Some of the sludge can be used for composting, and some may need to be disposed of. The biological systems in waste water treatment are often started from sludge extracted from another waste water treatment plant. This will require careful planning for operation on Mars. Sludge disposal may be relatively simple on Mars, since the atmospheric pressure is low, the water content of sludge would sublimate, leaving a residue that might be recoverable, or that can be stored for latter recuperation when adequate technologies are developed.
It is unlikely that the water can be entirely recycled. So the system will always be partly open. That is in fact one of the attractions of Mars, as compared to an enclosed space habitat: Mars has the resources required for an open system, and open system are both simpler and lighter than enclosed systems.
- Biological waste and biomass in various forms
- Martian regolith
- Various chemicals
- Perchlorates and perchlorate derivatives
- Metals and heavy metals
Waste water treatment processes
- Reverse osmosis
- Gravity separation
- Biological treatment
- Organic solids removal
Waste water treatment plant
The first waste water treatment plants will be packaged units provided from Earth. These types of units are already produced on Earth for buildings and communities isolated from the larger centralized waste water treatment plants available for towns and cities.