There are three ways to ...

There are three ways to remove ammonia 1.) raise the pH to 10.5 and air strip it (can be expensive to adjust pH up then back down)  2.) use a zeolite like Clinoptilolite and absorb the ammonia then use the zeolite as fertilizer (this can be expensive in high flows).  3.) use biological removal using an aerated/anoxic process to convert ammonia - nitrite-nitrate. This assumes that increased nitrate levels are not a problem.