What does water dissociate into?
Water dissociates into hydrogen and hydroxide ions.
So, ammonium hydroxide is a weak base. Weak base means that it dissociate slightly in water, that is, it does not dissociate 100% in water. This is because, when ammounium hydroxide reacts with water it forms hydrogen ions. But as the reaction is very revesible it will never react completely with water, that is, it will never dissociate completely with water. Thus, it is a weak base.
ammonia dissociate in air , if bromide available.products of dissociation is nitrogen and water. Ammonia can dissociate by UV in air. Ozone can turn bromide ion to bromate ion, and bromate ion can turn ammonia to nitrogen gas and water. The cheapest method of treating ammonia in water, is to pass the water stream through a wetlands, and let (micro)biology use it for a foodsource.