Biological Treatment for Greywater Reclamation

Abstract

Greywater reclamation is generally recognized as a viable solution to mitigate the challenges caused by water scarcity, increasing wastewater production, and increasingly stringent wastewater discharge permits. Biological processes may provide lower capital and operating costs, and less sludge production, than comparable physicochemical processes. This paper provides a general overview of the biological treatment processes currently available for greywater reclamation, including: rotating biological contactors, sequencing batch reactors, anaerobic sludge blanket bioreactors, constructed wetlands, membrane bioreactors, and hybrid membrane bioreactors. The advantages, disadvantages, and limitations of each of these technologies were examined in detail. The challenges of using reclaimed greywater were also examined in relation to the long-term sustainability of greywater reclamation. On balance, membrane-based processes were found to be among the most promising technologies for decentralized greywater reclamation, due largely to the quality of their treated water and compact size.

Keywords: rotating biological contactor, sequencing batch reactor, anaerobic sludge blanket bioreactor, constructed wetland, membrane bioreactor, hybrid membrane bioreactor