A review on promising strategy to decrease sludge production: Oxic-settlinganoxic/anaerobic process

Abstract

Recently, as environmental regulation for the removal of nutrients and excess sludge produced through wastewatertreatment has become more restricted, many wastewater treatment plants face serious challenges in terms of wasteproduction. Nowadays, the issue of excess sludge production has received considerable critical attention. Recentdevelopments in sludge treatment technologies have heightened the need for more promising strategies to reducesludge levels in a cost-effective and environmentally friendly manner. The purpose of this paper is to review recentresearch into the oxic-settling-anaerobic/anoxic (OSA) technology for sludge minimization. The OSA process is amodification of a conventional activated sludge system with the addition of interchange bioreactor parallel to recycledactivated sludge line. The OSA process seems to be a revolutionary and cost-effective alternative for sludge reductionapproach in the future. It is hoped that this research will contribute to a deeper understanding of the OSA process interms of sludge reduction efficiency, carbon and nutrient removal, operational parameters, possible reductionmechanisms and microbial community changes after the implementation of the OSA system and applied in thetreatment of real wastewater at full-scale.