Denitrification aided by waste beer in anaerobic sequencing batch biofilm reactor (AnSBBR)

Abstract The goal of research was to examine waste beer as a source of carbon in an anaerobic sequencing batch biofilm reactor (AnSBBR). It was demonstrated that waste beer enhanced denitrification. Observed biomass yield coefficient ( Y obs ) was one size of magnitude lower than for suspended-biomass reactors (0.03 ± 0.03 mgTSS mgCOD −1 ). The kinetic parameters (utilization of organic substrate and denitrification rates) were lower during the start-up period (88.8 mgO 2  L −1  h −1 and 17.37 mgN L −1  h −1 , respectively) than during stable operation of the reactor (212.4 mgO 2  L −1  h −1 and 34.66 mgN L −1  h −1 after 180 cycles). The metagenomic results showed that the abundance of Alcaligenes decreased from 18.39% to 0.88% (in 180 cycle), whereas the read numbers of Trichococcus increased gradually from 2.93% to 52.26% (in 180 cycle). Trichococcus was the dominant microorganism (52.3%). The low value of Y obs most likely resulted from the ability of Trichococcus to degrade complex organic compounds and extracellular polysaccharide substances (EPS), released from dead cells in deeper layers of the biofilm.