A Review of the Mechanisms of Faecal Coliform Removal from Algal and Duckweed Waste Stabilization Pond Systems

• Published in: American journal of environmental sciences 2015-01, Vol.11 (1), p.28-34
• Main Authors: Ansa, E. D.O., Awuah, E., Andoh, A., Banu, R., Dorgbetor, W. H.K., Lubberding, H. J., Gijzen, H. J.
• Format: Article
• Language: English
• ISSN: 1553-345X; 1558-3910
• DOI: 10.3844/ajessp.2015.28.34

The purpose of this paper is to provide a concise review of knowledge acquired in recent times on faecal coliform removal mechanisms in algal and duckweed ponds in a comparative way while identifying knowledge gaps that still exist. This review pays particular attention to little known removal mechanisms such as the role of algal biomass, attachment and sedimentation of faecal coliforms and the role of predation by macroinvertebrates and protozoans. Recent experiments showed that algal ponds are more efficient in faecal coliform removal due to the high pH and oxygenation that occur in the former and the rate of inactivation of faecal coliforms increases with increased algal biomass till a certain optimum concentration after which it decreases. This optimal algal concentration for maximum destruction of faecal coliforms can be affected by the quality and strength of the wastewater. Algae also appeared to have a destructive effect on faecal coliforms even in darkness, a phenomenon that may be the effect of toxic substances from the algae.