Introduction
Wastewater treatment clarifiers, also known as sedimentation tanks, are used in wastewater treatment plants to remove solid materials from the water being processed. The waste water treatment plant at the Arcata Marsh uses two clarifiers, one 26ft diameter tank and one 60ft diameter tank Fig.1.
Description
Clarification tanks work by allowing waste water become still enough for solids to settle to the bottom or float to the surface. Floating solids and oils are skimmed off of the surface by a large rotating arm called the surface skimmer Fig.2. On the bottom of the tank, which tapers down towards the center, there are rotating arms called scrapers that collect sludge and move it to the outlet at the center of the tank.
Resources
http://www.humboldt.edu/~smg59/clarifier.html
References
- Davis, Mackenzie, and Susan Masten. Principles of Environmental Engineering and Science. McGraw Hill: New York, NY 2004.
- http://www.humboldt.edu/~ere_dept/marsh/flow2.html
- http://en.wikipedia.org/wiki/Sewage_treatment#Sedimentation
- http://www.gc3.com/techdb/manual/clartext.htm