Sediment Basins (Continued) Flashcards
What is “Rill” erosion?
An erosion process in which numerous small channels only several inches deep are formed. It occurs mainly on recently cultivated soils.
What is “Grubbing”?
The operation of removing stumps and roots.
What is “Chemical Neutralization” in mining operations?
It is the process of adding an alkaline compound, such as lime or sodium hydroxide, to an acidic water in order to raise the pH and overcome an acidic condition.
What equipment can be used to remove suspended solids in process wastewater?
Cyclones, sloped-plated clarifiers, flocculation tanks and thickeners.
One of the purposes of an effluent structure from a settling pond or a tank is to control exit velocity. What is the potential adverse effect of high exit velocity?
Scouring, turbulence and short-circuiting.
Inlet and outlet design are very critical to good pond operation regardless of the size or shape of the pond. Two main objectives in designing inlets are:
To reduce the influent velocity and to allow the flow to spread across the width of the pond.
If a pump is used to remove effluent from a settling basin, it is desirable to have a seperate pumping pond. What are the purposes of a pumping pond?
By having a seperate pumping pond (or pool) following a main settling pond, it will prevent turbulence, scouring and short-circuiting in the main pool.
What are the typical maintenance operations of a settling pond?
The pond must be cleaned on a definite schedule to prevent the pond from being completely filled with sediment. The slope on banks of the pond must be protected and maintained. Pipes, weirs and structures should be checked regularly. Solids removed from the pond should be placed in a disposal area so that they do not wash back into the pond or escape to surface waters.
