New hybrid reactor concept incorporating a filter mesh for nitritation-anammox treatment of sludge return liquid

A new approach to perform partial nitritation-anammox in a single tank was investigated. The tank incorporated a mesh (opening size 1.0 × 1.2 mm) as permeable barrier to create two distinct reaction zones (aerated and anoxic). The study reports on the operation and optimization of a 13 L laboratory scale reactor to treat sludge reject water with an NH -N concentration of ∼750 mg·L . Performance throughout 250 days at increasing nitrogen loading rates is presented. The maximum loading rate applied was 1.5 kg NH -N·m ·d at a hydraulic retention time of 12 h. Typical composition of the effluent was ∼50 mg·L NH -N;