Purifying waste water with high ammonium nitrogen content

摘要

Process for purifying waste waters with a high ammonium nitrogen content comprises 1) mechanical pre-clarification; 2) physico-chemical purification; then 3) biological purification. Step 2) comprises (2a) percolation through a filter bed of granular material consisting of magnesium hydrogen phosphate-trihydrate (I) as active component and a binder component (II) comprising a reaction prod. of magnesium oxide and phosphoric acid, with ratio (I):(II) = 2:1 and a particle size of 100-500 (100-300) microns; and opt. (2b) percolation through a filter bed of magnesium hydroxide/magnesium oxide granulate.