A method of utilizing of the released carbon dioxide and of generating oxygen in sufficient quantities by obtaining a concentrate of rapidly multiplying microalgae, which is used as a dietary supplement in the nutrition of the crew of the International Sp

Abstract

The use of microalgae plays a crucial role in the utilization of carbon dioxide emitted by astronauts and the replenishment of oxygen in the spacecraft atmosphere. At present, research is being carried out on the Russian segment of the International Space Station (ISS) in the field of creating a life support system (LSS), which makes it possible to carry out long-term space missions. In the experimental complex "Bios-3" a number of hermetic chamber experiments based on the use of spirulina were carried out. Today, on the ISS, on the installed space photo bioreactor, experiments are being carried out to determine the possibility of using microalgae to utilize the carbon dioxide, emitted by astronauts, generate oxygen and obtain caloric food biomass through photosynthesis. However, the mere cultivation of microalgae in microgravity conditions is not enough, since the amount of biomass obtained is limited in time, and to maintain the cultivation of microalgae during a long flight, an additional amount of biomass is required, the delivery of which to the ISS is not cheap.

In this regard, the problem arises of concentrating microalgae from its nutrient medium under weightless conditions, while a part of the obtained concentrate of rapidly multiplying algae and the nutrient medium purified from algae cells will be added to a photo bioreactor for growing microalgae in a closed cycle according to the amount of biomass sufficient for long-term space flights. The article presents a developed method for obtaining a concentrate of rapidly multiplying microalgae for growing microalgae in a closed cycle according to the amount of biomass sufficient for long-term space flights. The developed method uses the effect of a constant electric current on a nutrient medium with microalgae, which makes it possible to simultaneously generate negatively charged microdispersed hydrogen bubbles and a negatively charged catholyte near the cathode, which, as a result of the electrostatic force of attraction between the electrodes, form strong complexes: living cells of microalgae + microdispersed hydrogen bubbles, concentrating along the entire anode zone, separated from the nutrient medium, which is localized throughout the cathode zone. The conical shape of the vessel containing complexes rapidly multiplying microalgae cells of microalgae + microdispersed hydrogen bubbles concentrated along the entire anode zone, and a nutrient medium localized along the entire cathode zone, allows moving the separated components into different ampoules under microgravity conditions. The separated nutrient medium and part of the concentrate of rapidly multiplying microalgae cells are returned to the photo bioreactor through a closed circuit for further cultivation of microalgae, removal of carbon dioxide and replenishment of oxygen in the ISS atmosphere during a long flight. Most of the remaining concentrate is used to feed astronauts to maintain their performance during long space flight.