Production of protein- and carbohydrate-EPS in activated sludge reactors operated at different carbon to nitrogen ratios

BACKGROUNDThis study aimed to clarify how a variation in the carbon to nitrogen (C/N) ratio in influent wastewater affects the production and composition of extracellular polymeric substances (EPS) in activated sludge. In the literature such a comparative analysis is rarely presented, most studies on EPS focus on simultaneous organic carbon removal and nitrification whereas little attention is paid to the case of low organic load or separate-stage nitrification.