Lagoons and Ponds Flashcards
Cattails, bushes, and grass at the water’s edge should be cut or killed in order to discourage…
Mosquito breeding
The embankment of wastewater stabilization ponds should be covered with…
Grass with deep, penetrating roots
Important operations and maintenance aspects of waste stabilization ponds include control of…
Weeds and insects
Scum rafts in a waste pond…
Are undesirable because they will cause odor and reduce sunlight penetration
Surface agitation in a lagoon is a recommended method of controlling…
Cattails
The highest DO content may be expected at
3 PM
The most favorable time for biological activity in wastewater stabilization ponds is in…
Summer
A long hot period may cause overloading of a lagoon by…
Lowering the DO saturation level
When the population of algae and it’s activities increase the pH of a waste stabilization pond usually…
It can fluctuate
The primary cell of a waste stabilization pond…
Provides the same type of treatment as a primary treatment plant
Emergent vegetation on the pond bottom such as cattails may be best controlled by…
Spraying and keeping the water depth greater than 2 feet
In spraying to control rushes and cattails, chemicals should be mixed in…
Plain water
In the design and operation of an oxidation pond, which of these factors is important…
Surface area, depth and shape, inlets and outlets, control of weeds and vegetation around the edges to prevent mosquito breeding.
Depth is an important factor to be considered in the design and operation of an oxidation pond. The 3-ft depth presently recommended has been selected because…
A. Common water plants grow best at 3-ft depth
B. Common water plants are discouraged at this depth, and a reasonable depth of sunlight penetration is obtained
C. Vertical circulation is obtained at greater depths, and horizontal currernts prevail at shallower depths, which seriously interferes with performance
B. Common water plants are discouraged at this depth and a reasonable depth of sunlight penetration is obtained
An aerated cell is followed by _______ or ___________
A standard cell and polishing pond, a clarifier and chlorination
Performance of waste stabilization ponds is a function of…
pH
The gas produced in largest volume as a result of the proper digestion of wastewater solids in a lagoon is…
Carbon dioxide
The basis of operation of a wastewater lagoon for secondary treatment is…
Aerobic organisms and algae
Biological activity within a lagoon is carried on by…
Aerobic and anaerobic bacteria, algae
In a stabilization pond, oxygen for the aerobic bacteria, comes from a form of plant life. This form of plant life is called…
Algae
Most common cause of odors from waste stabilization ponds is…
Hydrogen sulfide
Which of the following produce the most desirable results in an oxidation pond…
Algae
Hydrogen sulfide is ordinarily not a problem in properly designed and operated waste stabilization ponds because…
It’s in very low concentrations
Select the chemical that may be used in attempt to correct septic conditions in a new oxidation pond…
Sodium nitrate
Odors from waste stabilization ponds are usually caused by…
Overloading of the pond
Facultative ponds are…
Aerobic on the top and anaerobic on the bottom
