Effect of lag-phase in the transition from oxic to anoxic conditions on the performance of the sequencing batch reactor

Sequencing batch reactors (SBRs) are usually preferred as small and decentralized wastewater treatment systems. Using a frequent enough switching between oxic and anoxic conditions, it is possible to bypass the second step of nitrification (i.e. conversion of nitrite to nitrate nitrogen) in SBR. The effect of oxic/anoxic ratio (R) on nutrient removal from municipal wastewater was examined in 5 m3 pilot-scale SBR operated at ambient temperature. During the react phase, the reactor was intermittently aerated specific aeration intervals. DO, pH and oxidation