Editing Space settlement (section)

===Food production===
[[Organic chemistry|Organic]] materials for food production would also need to be provided. At first, most of these would have to be imported from Earth. {{cn|date=January 2018}} After that, feces recycling should reduce the need for imports.{{cn|date=January 2018}} One proposed recycling method would start by burning the cryogenic distillate, plants, garbage and sewage with air in an electric arc, and distilling the result.{{Citation needed|date=November 2009}} The resulting carbon dioxide and water would be immediately usable in agriculture. The nitrates and salts in the ash could be dissolved in water and separated into pure minerals. Most of the nitrates, potassium and sodium salts would recycle as fertilizers. Other minerals containing iron, nickel, and silicon could be chemically purified in batches and reused industrially. The small fraction of remaining materials, well below 0.01% by weight, could be processed into pure elements with zero-gravity [[mass spectrometry]], and added in appropriate amounts to the fertilizers and industrial stocks. It is likely that methods would be greatly refined as people began to actually live in space settlements.