How the ISS reuses water
NASA/Kennedy Space Center image KSC-08pd3209, Water Recovery System rack 2 prepared for delivery to the ISS on STS-126 in 2008. Source: https://images-assets.nasa.gov/image/KSC-08pd3209/KSC-08pd3209~medium.jpg. NASA credit; public-domain U.S. federal work. This shows the flight hardware before launch.
Aboard the International Space Station, the water system collects urine and moisture condensed from crew breath and perspiration. Specialized units separate, filter, and purify the water; sensors check its quality, and water that fails the checks is processed again. After treatment, the water returns to the supply for drinking, food preparation, and hygiene—it is processed water, not untreated waste. Microgravity makes ordinary washing difficult: water does not drain downward and can float through the cabin as droplets, so the crew uses wet wipes and products that do not need rinsing.