In one embodiment, an ammonium removal method can comprise: removing a
multivalent cation from a stream comprising ammonium to form a treated
stream; converting the ammonium in the stream to ammonia by increasing
the pH of the stream; and separating the ammonia from the treated stream
to form a separated stream and gaseous ammonia. In another embodiment, an
ammonium removal method can comprise: a multivalent cation from a stream
comprising ammonium to form a treated stream comprising a total of less
than or equal to about 50 ppm by weight of multivalent cations;
increasing the pH of the stream to a conversion pH; converting the
ammonium to ammonia; and separating the ammonia from the treated stream
to form a separated stream and gaseous ammonia.