Brown water treatment is nothing new. Urine is especially hard to purify, but it can be done.
NASA - Sci-fi Life Support
Urine recovery is an engineering challenge: "Urine is so much dirtier than ordinary humidity," Carrasquillo explains. "It can corrode hardware and clog hoses." ECLSS uses a purification process called vapor compression distillation: urine is boiled until the water in it turns to steam. The steam—essentially clean water vapor except for some traces of ammonia and other gases—rises into a distillation chamber, leaving behind a concentrated brown soup of impurities and salts that Carrasquillo charitably calls "brine" (which is discarded). The steam is cooled and condenses back into liquid. This steam distillate is then mixed with the humidity condensate, and the water further purified to become potable. ECLSS can recover 100 percent of moisture in the air, and 85 percent of the water in urine, resulting in a net overall recovery efficiency of about 93 percent.
Of course, I'm right with you kernel - osmotically filtered urine isn't my cup of tea - or chicken and rice!