Achieving partial denitrification using organic matter in brewery wastewater as carbon source

Abstract

To find a cost-effective carbon source for partial denitrification (PD), brewery wastewater was utilized to test the viability of initiating PD. The Sbre (sludge from the biological treatment tank of Tsingtao Brewery Plant sewage treatment station) and Slab (sludge from laboratory) were fed with brewery wastewater at CODCr/NO3−-N (C/N) ratios of 8.0–10.0 and 5.0 for 95 days at 25 ± 1 °C, respectively. The mean NO3−-N to NO2−-N transformation ratio (NTR) in long-term operation was 40.0% in the Sbre system and 83.2% in the Slab system. Batch tests with C/N ratio of 2.2–4.4 were conducted after 95 days incubation and the result suggested that C/N ratio of 4.3 ± 0.1 contributed more to NO2−-N accumulation in both systems. Thauera bacteria, known to be beneficial for NO2−-N accumulation, became the dominant community. The relative abundances of Thauera on day 95 in the Sbre and Slab system were 83.36% and 79.11%, respectively.