Referring to a video here, describing a filter that treats wastewater, wouldn't urine in the wastewater not get filtered out because a sand filter alone does not separate urine from water? How is clean water produced from urine in water treatment facilities where large volumes of waste water are being treated everyday?

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    $\begingroup$ Filtration removes suspended solids. Urine is in solution not suspension. $\endgroup$
    – Waylander
    Aug 26, 2022 at 7:04
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    $\begingroup$ It would need some big biotopic reservoir and then final fine filtration and desinfection. Other methods to get drink water would be much cheaper and easier, if available. $\endgroup$
    – Poutnik
    Aug 26, 2022 at 7:15
  • $\begingroup$ In the years 1970, urine was electrolyzed on board space capsules (Apollo) by solar cells. The $\ce{H2}$ and $\ce{O2}$ gases produced were then recombined in galvanic cells where they were producing first pure water, and then electric current necessary to charge the batteries on board. This is a way to obtain drinkable water. $\endgroup$
    – Maurice
    Aug 26, 2022 at 8:56
  • $\begingroup$ As noted in video, processes differ from place to place. Here’s one approach:news.climate.columbia.edu/2011/04/04/… $\endgroup$
    – Andrew
    Aug 26, 2022 at 12:54
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    $\begingroup$ This filtration will principally work (provided you aerate the inlet water sufficiently), because a biofilm grows on the sand that removes nutrients. Generally speaking. The output is certainly better than what many people drink day to day on this planet. Of course it is nowhere near real drinking water, and magnitudes away from what I have as (non-chlorinated) tapwater at home. How long it will work is hard to tell, and depends strongly on how clean the input water is. The problem are human pathogens, and how much (or little) the input is diluted with nutrient-free (rain) water. $\endgroup$
    – Karl
    Aug 26, 2022 at 14:28

3 Answers 3


Aerobic and Anaerobic processes are used to remove the organic content of the urine containing mainly urea and uric acid. The NH groups are oxidized to NO3 groups by the nitrobacter bacteria of the ETP culture. This nitrate can then be used by the Sludge of the ETP itself or be in the water as TDS. This water can then go through RO, MEE or TVR to remove the TDS down to a satisfactory level and then use urine as potable water. A simple sand filter won't do much. Activated carbon would help but would be Over the Limit quite soon. Adding stuff like NaOCl, peroxide, UV etc can help too but ultimately, its the aerobic degradation that does the majority of work


There are many ways to make clean water from urine in a wastewater treatment plant. One way is to use reverse osmosis. This process uses a semipermeable membrane to remove impurities from water. Another way is to use activated carbon filters. These filters remove impurities by adsorbing them onto the surface of the carbon.


Here is a source Applications of ozone for industrial wastewater treatment — A review, to quote:

Ozone coupled with ultraviolet radiation and/or hydrogen peroxide (advanced oxidation) is being utilized to destroy organic contaminants in groundwaters at munitions manufacturing plants and at Superfund sites (hazardous wastes).

Another source, Recent advances in ozone-based advanced oxidation processes for treatment of wastewater- A review, to quote:

Advanced oxidation processes (AOPs) are considered as a good option for removing recalcitrant organic materials in wastewater by oxidation reactions with powerful, non-selective hydroxyl radical (OH•). Ozone alone does not cause complete oxidation of some refractory organic compounds and has a low reaction rate. The ozone is combined with H2O2, UV light, catalyst, ultrasound to enhance the generation of hydroxyl radicals to increase the efficiency of the treatment process. The ozone-based AOPs have been proved to be effective in detoxifying an ample range of industrial effluents containing recalcitrant organics, pharmaceutical products, pesticides, phenols, dyes, etc.

So, basically, the ozone facilitate the introduction of powerful oxidizing species on contact with the wastewater that can chemically attack complex molecules, breaking them down into more simple compounds, like water, carbon dioxide, nitrogen based oxides, etc., thereby permitting there removal.

I hope this helps.


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