scale Biological Reactor

Nitrification, the oxidation of ammonia to nitrate catalyzed by bacteria, is a key part of the global nitrogen cycle. In the first step of nitrification, chemolithoautotrophic ammonia oxidizers transform ammonia to nitrite, which subsequently oxidizes to nitrate by nitrite-oxidizing bacteria. This process can be affected by several factors. In this study, the effect of influent COD/N ratio on nitrification rate in a bench-scale biological reactor was investigated. Experiments were carried out using synthetic wastewater. The initial ammonium concentration was 25 mg NH -N L 1. The effect of COD/N ratio between 10.01 0.083 and 24.08 0.22 gCODgN-1 on nitrification rate was investigated by varying the COD loading supplied to the reactor. From the results obtained, it may be concluded that in the range of 10.01 0.083 to 14.15 0.17 gCODgN-1, a direct relationship holds between COD/N ratio and nitrification rate. However, an indirect relationship holds between COD/N ratio and nitrification rate at ratios above 14.15 0.17 up to 24.08 0.22 gCODgN-1.