Effect of temperatures and alternating anoxic/oxic sequencing batch reactor (SBR) operating modes on extracellular polymeric substances in activated sludge

In order to investigate the effect of temperatures and operating modes on extracellular polymeric substances (EPS) contents, three sequencing batch reactors (SBRs) were operated at temperatures of 15, 25, and 35 °C (R , R , and R , respectively), with two SBRs operated under alternating anoxic/oxic conditions (R and R , respectively). Results showed that higher contents of tightly bound EPS (TB-EPS) and total EPS appeared in R , while loosely bound EPS (LB-EPS) dominated in R . In all three kinds of EPS (LB-EPS, TB-EPS and total EPS) assessed, protein was the main component in R and R , while polysaccharides dominated in R . Moreover, compared with R , R was favorable for the production of the three kinds of EPS. Furthermore, three kinds of EPS and their components were augmented during the nitrification process, while they declined during the denitrification process under all conditions except for R .