The Effect of Organics on Shortcut Nitrification and Modification Method of Measured Organics Concentration

To study the modification method of the measured concentration of organics and the effect of organics on the shortcut nitrification in wastewater containing NO₂^-, the effect of NO₂^- on the measurement of organics were investigated by preparing glucose solution, sodium nitrite solution and glucose-nitrite mixed solution in different concentrations, and the degradation of organics and its effect on shortcut nitrification during nitrite accumulation were studied in the SBR which had achieved nitrification. The result showed that as NO₂^- existed in wastewater, the organics concentration had to be modified in terms of the formula (modified COD= measured COD-[NO₂^--N](in COD). In the case of low concentration of DO (0.2-0.8mg/L), the system could endure relatively high concentration of COD and NO2- was not so toxic to the bacteria that COD was unable to be eliminated. Meanwhile denitrification was significant in the system when the concentration of COD was comparatively high.