Sorption of Ammonium-Ions by Clinoptilolite and by Strongly Acidic Cation Exchangers

The sorption capacity of two natural sorbents of different origin and of Wofatit KPS is determined by dynamic laboratory investigations and the influence of a thermal pretreatment of clinoptilolite, of the type and quantity of regenerants and of the presence of other cations is investigated. There are represented results of the ammonia removal from biologically treated municipal wastewater and of the removal of caesium-ions from laundry wastewaters. The capacity of clinoptilolite is lower than that of the ion-exchange resin, but clinoptilolite has the advantage of a considerably higher affinity for ammonium-ions, so that it can be used also in the presence of other salts in water to be treated. The ammonium concentration should not exceed 30 mg/l, in order to avoid too short filter runs.