Iodine is added to acceptable water to prevent the growth of microbes, and the water is then stored for the crew to use at a later point. Sensors then check the purity of the water with water that doesn’t meet standards sent back for reprocessing. Like the other collected wastewater, this is treated by the WPA with a series of specialized filters and a catalytic reactor that breaks down any trace contaminants that may remain. This results in humid air being created that is not dissimilar to the breath of ISS crew members, and this can be collected by ECLSS dehumidifiers. The BPA takes brine created by the UPA and passes it through a series of special membranes introducing it to warn dry air that evaporates its water content. 'We have now demonstrated that we can reach total water recovery of 98%, thanks to the brine processor.' 'Before the BPA, our total water recovery was between 93 and 94% overall,' said ECLSS water subsystems manager Jill Williamson. While demonstrating its operations in the microgravity of space, the BPA pushed the ECLSS to the 98% goal. A Brine Processor Assembly (BPA) was added to the UPA to extract this remaining wastewater. The UPA element of the ECLSS distills urine, but brine is produced as a by-product of this process, and that still contains some unused water. This collected water is sent to the Water Processor Assembly (WPA), which then produces drinkable water. The ECLSS is made up of a combination of hardware, including a Water Recovery System that collects wastewater and advanced dehumidifiers that capture moisture from the air of the ISS as a result of the crew’s breath and sweat. The water recovery milestone was achieved by the Environmental Control and Life Support System (ECLSS) during a demonstration of the improved Urine Processor Assembly (UPA), which recovers water from urine using vacuum distillation.

Setools space engineers