Break Point Chlorination

I am looking for some insight on breakpoint chlorination in RO rejects containing Ammonia. In ionized form. There is about 1 -7ppm of Ammonia as N. Need to bring it down to 0.3 ppm by Breakpoint Chlorination. What dose ratio should be considered to convert Ammonia into Nitrogen gas? AWWA recommends 12: 1 ratio. Will there be Nitrogen Trichloride formation. But the pH of the solution is between 7.5 to 8.5. Nitrogen Trichloride usually forms at lower ph about 4.2. Can you please recommend possible solutions here. Thanks in advance Regards, Abilash