Resuspension and oxygen uptake of sediments in combined sewers

Abstract Combined sewer sediment properties were studied in small-scale laboratory flumes. Physical and biological characteristics of freshly remoulded sediment beds and beds undisturbed for 1–4 days were examined. When sediment beds were incubated for 1–2 days, the beds became covered with biofilm and the bed volumes increased by 20–40% due to the formation of methane-filled cavities. The bed strength decreased with increasing incubation time. The oxygen uptake rates of biofilm-covered sediment beds were on average five times higher than those for biofilm-free beds.