Scope of improvement of treatment capacity of activated sludge process by hybrid modification

Abstract

Activated sludge process is widely used for wastewater treatment throughout the world with various needful modifications. The hybrid modification of conventional activated sludge process utilizes a suspended media of appropriate inert material or fixed surface that serves as carrier material for growing active microorganisms on its surface. As a result the carrier media allows the biological reactor to operate at a higher biomass concentration, compared to the conventional activated sludge process. The hybrid modification of conventional activated sludge process can be configured either to provide additional capacity for biochemical oxygen demand (BOD) removal or to facilitate nitrogen control. The process is ideally suited for upgrading the existing system with a nominal modification. The present paper summarizes various research work towards the hybrid system to review the requirements and scope of modification, development and evolution of the hybrid modification. The review concludes with an assessment of financial viability of hybrid modifications.