DE3635843

Separating off ammonia from exhaust air, or from gases stripped from waste water (effluent), by means of nitrifying bacteria and the reactors necessary for this are described in the process. In accordance with this, the nitrifying bacteria such as Nitrosomonas europaea and Nitrobacter winogradskyi, are ignited on limestone in the moistened, oxygen-rich air stream or gas stream, in which case they oxidise the ammonia to form nitric acid which is neutralised by the limestone to form nitrates. The carbon dioxide released is at least partially utilised as a carbon source for the growth of the microorganisms. The nitrates formed are separated off by wet or dry means with the reactor devices described and are isolated alone or together with unreacted limestone and used as fertiliser.