The process traps particulate material and can, under ideal conditions, convert ammonia to nitrite and nitrate ultimately to nitrogen gas.

These either convert ammonia to nitrate (removing nitrogen at the expense of aquatic plants), or to sometimes remove phosphate.

Bacteria are able to convert ammonia to nitrite and nitrate but they are inhibited by light so this must occur below the euphotic zone.

The liver converts ammonia to urea (urea cycle).

Ammonia levels in the blood rise when the liver is not able to convert ammonia to urea.

The liver normally converts ammonia into urea, which is then eliminated in urine.

Ultraviolet light would convert ammonia back into N2 in about 30 years, so there would have to be a continuous resupply of NH3.

Many designs are used, with different benefits and drawbacks, however the function is the same: reducing water exchanges by converting ammonia to nitrate.

Next, a scum of specially designed algae would convert ammonia and methane into animal fodder.

Therefore many organisms convert ammonia to urea, even though this synthesis has a net energy cost.