Main influence factors for shortcut nitrification in a SBR treating anaerobic digested piggery wastewater.

To develop a shortcut nitrification process for treating anaerobic digested piggery wastewater with a high ammonia concentration, a sequencing batch reactor (SBR) was introduced, and the temperature, ammonia nitrogen loading rate (R_nl) and aeration time were investigated as the significant influence factors of the shortcut nitrification. The shortcut nitrification process could be established in the SBR at 28 °C or 15 °C with the identical dissolved oxygen (DO), ranged from 1 to 2 mg ⋅ L^-1. But the ammonia removal and nitrite accumulation rate R_na were decreased from 71. 1% and 96.7% to 52.8% and 85.4%, respectively, when the temperature was dropped from 28 °C to 15 °C. Though the ammonia removal rate was decreased to 48. 6% since the R_nl had been increased from 0. 56 to 2.18 kg ⋅ m^-3 ⋅ d^-1 at 28 °C, a R_na as high as 96. 8% was obtained, indicating that an excellent shortcut nitrification occurred in the SBR. To obtain a superior ammonia oxidation with a higher R_nl, extension of aeration time would be supportive. But an excessive aeration could result in an increase in nitrate and a decrease in R_na, which was unfeasible for the shortcut nitrification process in the SBR. [ABSTRACT FROM AUTHOR]