Guidelines on Design of Aerated Ponds

Construction of Aerated Ponds has to take into account different criteria in order to be fully efficient and serve the needs of wastewater treatment purposes. There are several design considerations that an engineer has to find out in order to determine the best setup such as the overall detention time, pond location, and finally presence of dikes plus embankment including also the pond bottom construction.

Detention Time
Basically the detention time of wastewater is measured by the number of days which is calculated based on a function of percent of total incoming wastewater BOD targeted to be removed (measured in ppm) divided by a reaction coefficient which is dependent on the water temperature. Normally the value is fixed at 0.20 per day for wastewater with temperature at 20 degree Celsius while the value is only 0.08 per day at freezing value. As a guideline, usually the design of aerated pond should have the capacity to retain water for at least 5 to 10 days under normal condition while in colder climate; it has to go higher for at least 8 to 20 days due to slower bacterial metabolism.

Pond Location
The aerated pond should be situated as far as possible from habitation or rainwater catchments area. Roughly the best distance should be about minimum 250 meters in order to prevent odor and health complaints affecting the community there. If possible, determine as well whether the calculated surrounding area might have future development plans based on confirmation and checking with local municipalities. Other than what was mentioned here, the engineer has to also take into account whether there is sufficient land area, in case there’s a need for future expansion plan to upgrade the wastewater aerated pond. All these have to meticulously figured out in details before coming to a final conclusion.

Dikes and Embankment
Both dikes and embankment are other important areas to look into including the pond bottom construction design. Basically the dikes should be made in such a way that seepages are reduced to minimal level so that this will avoid possible contamination to underground water supply. Generally, guidelines on the construction of embankment slopes should be supported by typical bank stabilization and liners and also the area surrounding the embankment should be cleared. All these are important to prevent erosions on the interior slopes which will cause problems later part. Finally the pond bottom should be compacted as well while the level should be as flat as possible.

Understand the concept of Aeration System



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