What Is The Secret Of The Space Water Circulation System, Which Can Filter Sweat?

Water is the most precious resource in space life. It is estimated that it will cost at least $83 thousand to pport 1 gallons of water to sub orbital space.

In order to solve the problem of astronaut space life water consumption, NASA JSC began signing small business innovation research (SBIR) contract with nanomaterial company Argonide in 2000 to develop water cycle filtration and disinfection system.

In 2002, the company developed a NanoCeram filter based on the core technology of nanofibers, which has been proved to provide excellent purification effect for drinking water in space. With this technology, the sweat and urine of astronauts can also be integrated into the water recovery system to achieve efficient purification.

The NanoCeram filter element is made of nano alumina fiber and made of glass fiber 9.65 mm in diameter. The average diameter of nanofibers is about 2 nm, the average length is about 200~300 nm, the specific surface area of the filter is as high as 500 m2/g, and the fiber has positive charge.

During filtration, impurities with a size greater than 2 m are directly filtered because of the intercepting effect of nanofibers, while finer particles are adsorbed and filtered by nano alumina fibers with positive charges due to a slight negative charge. Therefore, the filtration efficiency of the monolayer filter media for 0.025 m particles can reach 99.99% (3 layers of medium can reach 99.9999%), thereby effectively removing bacteria, viruses, organic matter particles, parasites and heavy metals such as iron and lead in water.

At the same time, because the filter medium has a larger pore diameter than its filtered impurity particles, it has the advantages of high fluidity, high volume of dust and low pressure drop.

Although NanoCeram is developed for astronauts' space water use, as a highly versatile technology, it has great potential application value in the civilian field. There are about 900 million people in the world who lack safe and purified drinking water. Every year 3 million to 4 million people die from diseases related to water pollution; and field marching and hiking are also urgent needs for portable real-time water purification equipment.

Therefore, NanoCeram technology has been expanded rapidly in the civilian field.

For example, in 2006, Argonide authorized the NanoCeram filtration technology to Ahlstrom (OSLON) company. After that, OSLON completed the commercial production of the nano aluminum fiber material based on the NanoCeram technology, and further enhanced the filtration performance of the medium (Disruptor PAC) by adding activated carbon powder (PAC), which has been widely applied in the field of drinking water filtration.

In addition, NASA's report on the marketization of NanoCeram technology in 2017 introduced a portable water purification device Water ResQ and its upgraded version Mobile Water ResQU.V. system, which is headquartered in Utah water purifier company Water Pure Technologies.

The system is equipped with a water purification system in a portable suitcase, which can be charged by solar panels or manually recharged. It can filter 2.9 gallons of water per minute, and can add extra filtration modules for highly polluted water.

At present, the company has obtained orders from fire parachute brigade, emergency rescue organization and military.

On the basis of space water circulation filtration and filtration technology, NASA is further improving its space circulation water's clarity, so as to produce IntraVenous (IV) water in space.

Because astronauts are sick or injured in every space mission, and the NASA International Space Station patient database has confirmed that there are 115 kinds of medical stations that may occur in space, they need intravenous injection. For example, 1 severely burned astronauts need about 100 L (only 30 L) in the first 3 days during the treatment of IV.

A recent NASA study shows that Mars missions may require up to 248 L of intravenous injections, but currently only 12 L of liquid can be stored in the space station, and the huge cost of IV liquid access to space is huge. It takes a lot of space, aseptic height and a limited shelf life.

For this reason, NASA has set up a project called IntraVenous Fluid GENeration for Exploration Missions (IVGEN). A IV water purification test system was developed by the Kennedy Space Center and Glen research center. It was tested in the international space station in 2010. From the test results released by NASA, there are still some defects in the concentration of salt solution and bubble control, and the project ended in failure.

But it is foreseeable that if the technology is developed successfully, it will have a very good application prospect and value in field wars, submarines, ocean fleets and civilian medical rescue in addition to the medical field of the space station.