Retracted: Effects of Carbon Sources on Filamentous Bulking under Alternating Oxic-Anoxic Model

In this study, the effect of different carbon sources on realizing shortcut nitrification-denitrification was investigated. Two lab-scale sequencing batch reactors (SBRs) were operated by using artificial wastewater under alternating oxic-anoxic model. SBR A used starch as carbon source and glucose was used for SBR B. The results showed that the average removal rates of ammonia nitrogen and COD in SBR A and SBR B were 90.23% and 92.85%, 76.22% and 83.44%. Both reactors realized shortcut nitrification-denitrification in the end of test, and the NAR could be above 80%. However, the NOB elutriation ratio of SBR B was faster than SBR A even though that the nitrite accumulation produced in SBR A earlier. SBR A got sludge bulking with the increase of the sludge volume index (SVI), and the systemic removal efficiency of total nitrogen and organic matter reduced. As time went on, the microorganisms in the sludge adapted to the carbon source and the SVI was approximate 300ml/g steadily.