Environmental Engineering Reference
In-Depth Information
7.2.1.2.1 aerobic Ponds
In aerobic ponds, which are not widely used, oxygen is present
throughout the pond. All biological activity is aerobic decomposition.
7.2.1.2.2 anaerobic Ponds
Anaerobic ponds are normally used to treat high-strength indus-
trial wastes. No oxygen is present in the pond, and all biological activity
is anaerobic decomposition.
7.2.1.2.3 facultative Ponds
The facultative pond is the most common type of pond (based on
processes occurring). Oxygen is present in the upper portions of the
pond, and aerobic processes are occurring. No oxygen is present in the
lower levels of the pond where the processes occurring are anoxic and
anaerobic.
7.2.1.2.4 aerated Ponds
In the aerated pond, oxygen is provided through the use of mechan-
ical or diffused air systems. When aeration is used, the depth of the
pond and the acceptable loading levels may increase. Mechanical or dif-
fused aeration is often used to supplement natural oxygen production
or to replace it.
7.2.2 Process Control Calculations for stabilization Ponds
Process control calculations are an important part of wastewater
treatment operations, including pond operations. More significantly,
process control calculations are an important part of state wastewater
licensing examinations—it is simply not possible to master the licens-
ing examinations without being able to perform the required calcula-
tions. Thus, whenever possible, example process control problems are
provided to enhance your knowledge and skill.
7.2.2.1 Pond Area in Acres
Area (ft )
43,560 ft /acre
2
Area (ac)
=
(7.1)
2
7.2.2.2 Pond Volume in Acre-Feet
Volume (ft )
43,560 ft /ac-ft
3
Volume (ac-ft)
=
(7. 2)
3
