Step Sludge Recirculation was proposed as multistage configuration to enhance BOD removal with minimal sludge production. SSR proved to be more efficient than conventional multistage at high organic load, resulting in 98% BOD removal with good effluent quality. SSR is assumed to enhance predation phenomena in activated sludge. This assumption was qualitatively verified with a kinetic model.
Experimental validation of a kinetic model for activated sludge process with step sludge recirculation / DI PALMA, Luca; M., Lalla; Merli, Carlo; Pernetti, Mimma. - STAMPA. - 3:(2002), pp. 1175-1178. (Intervento presentato al convegno 5th Specialized Conference on Small Water and Wastewater Treatment Systems tenutosi a Istanbul, Turchia nel 24-26 September 2002).