Aerated Pond

An aerated pond is a large, mixed aerobic reactor. Mechanical aerators provide oxygen and keep the aerobic organisms suspended and mixed with water to achieve a high rate of organic degradation.

Increased mixing and aeration from the mechanical units means that the ponds can be deeper and tolerate much higher organic loads than a maturation pond (see waste stabilisation ponds). The increased aeration allows for increased degradation and increased pathogen removal. As well, because oxygen is introduced by the mechanical units and not by light-driven photosynthesis, the ponds can function in more northern climates.  

Design Considerations

Influent should be screened and pre-treated to remove garbage and coarse particles that could interfere with the aerators. Because the aeration units mix the pond, a subsequent settling tank is required to separate the effluent from the solids.

The pond should be built to a depth of 2 to 5 m and should have a detention time of 3 to 20 days, depending on the treatment target.

To prevent leaching, the pond should have a liner. This can be made from clay, asphalt, compacted earth, or any other impervious material. A protective berm should be built around the pond, using the fill that is excavated, to protect it from runoff and erosion. 

Appropriateness

A mechanically aerated pond can efficiently handle concentrated influent and significantly reduce pathogen levels. It is especially important that electricity service is uninterrupted and that replacement parts are available to prevent extended downtimes that may cause the pond to turn anaerobic.

Aerated ponds can be used in both rural and peri-urban environments. They are most appropriate for regions with large areas of inexpensive land located away from homes and businesses. Aerated lagoons can function in a larger range of climates than Waste Stabilization Ponds and the area requirement is smaller compared to a maturation pond.

Health Aspects/Acceptance

The pond is a large expanse of pathogenic wastewater; care must be taken to ensure that no one comes in contact with or goes into the water. The aeration units can be dangerous to humans and animals. Fences, signage, or other measures should be taken to prevent entry into the area.

Operation and Maintenance

Permanent, skilled staff is required to maintain and repair aeration machinery and the pond must be desludged every 2 to 5 years.

Care should be taken to ensure that the pond is not used as a garbage dump, especially considering the damage that could result to the aeration equipment.

References

Further Readings

  • Cover image of a reference book or miscellany.

    TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; SCHERTENLEIB, R.; ZURBRUEGG, C. (2014): Compendium of Sanitation Systems and Technologies (Arabic). 2nd Revised Edition. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). PDF

    This is the Arabic version of the Compendium of Sanitation Systems and Technologies. The Compendium gives a systematic overview on different sanitation systems and technologies and describes a wide range of available low-cost sanitation technologies.

  • Cover image of a reference book or miscellany.

    EAWAG/SANDEC (Editor) (2008): Sanitation Systems and Technologies. Lecture Notes . Duebendorf: Swiss Federal Institute of Aquatic Science (EAWAG), Department of Water and Sanitation in Developing Countries (SANDEC). PDF

    Lecture notes on technical and non-technical aspects of sanitation systems in developing countries.

  • Cover image of a reference book or miscellany.

    CRITES, R.; TCHOBANOGLOUS, G. (1998): Small and Decentralized Wastewater Management Systems. New York: The McGraw-Hill Companies Inc.

    Decentralised wastewater management presents a comprehensive approach to the design of both conventional and innovative systems for the treatment and disposal of wastewater or the reuse of treaded effluent. Smaller treatment plants, which are the concern of most new engineers, are the primary focus of this book.

  • Cover image of a reference book or miscellany.

    KONE, D. (2002): Epuration des eaux usées par Lagunage a Microphytes et a Macrophytes en Afrique de l'Ouest et du Centre- Etat des lieux, performances épuratoires et critères de dimensionnement. Lausanne: Swiss Federal Institute of Technology (EPFL).. PDF

    Stabilization ponds are a very promising sustainable centralized wastewater treatment option for West Africa due to the favourable climate. Pilot studies could demonstrate their performance in the local context; however none of the full-scale applications works. Besides the poor economic situation and little political support, it is also the lack of training and research that contributes to this situation. This work presents the establishment of an international research collaboration network and main technical recommendations based on an exhaustive assessment on the state-of-the-art of stabilization ponds in the West-African context.

    Language: French

  • Cover image of a reference book or miscellany.

    TCHOBANOGLOUS, G.; BURTON, F. L.; STENSEL, H. D.; METCALF & EDDY Inc. (Editor) (2003): Wastewater Engineering, Treatment and Reuse. New York: McGraw-Hill Companies, Inc.. PDF

  • Cover image of a reference chapter of a book/miscellany.

    SPERLING, M. von (2005): Part Three: Stabilization Ponds. In: SPERLING, M. von; LEMOS CHERNICHARO, C.A. de (2005): Biological Wastewater Treatment in Warm Climate Regions Volume 1. London, 495. URL [Accessed: 16.02.2011].

    Almost 200 pages on the treatment process and design parameters of waste stabilisation ponds. Very exhaustive.

Case Studies

  • Cover image of a reference book or miscellany.

    RUAF (Editor) (2008): Water for Urban Agriculture. Leusden: Resource Center on Urban Agriculture and Food security (RUAF) Foundation. PDF

    Various case studies on the reuse of pond and lagoon treated water in urban agriculture.

Training Material

  • Cover image of a reference chapter of a book/miscellany.

    SPERLING, M. von (2005): Part Three: Stabilization Ponds. In: SPERLING, M. von; LEMOS CHERNICHARO, C.A. de (2005): Biological Wastewater Treatment in Warm Climate Regions Volume 1. London, 495. URL [Accessed: 16.02.2011].

    Almost 200 pages on the treatment process and design parameters of waste stabilisation ponds. Very exhaustive.

  • Cover image of a reference book or miscellany.

    WHO (Editor) (1987): Wastewater stabilization ponds: Principles of planning and practice.. Alexandria: World Health Organization Regional Office for the Eastern Mediterranean. PDF

    The book has been divided in two parts. Part A provides a comprehensive summary concerning the various aspects of constructing, operating and maintaining pond systems. It also considers aspects such as management and safety. Part B is intended for persons making the preliminary designs on which cost estimates and, hence, choices can be made. In particular, the appendix and annex provide a working example and a simple methodology to help the designer in preparing adequately detailed designs.