March 10, 2015
Virtual Wastewater Treatment Plant
Raw wastewater enters the treatment facility at the beginning of the treatment plant, then pumped to the wastewater treatment facility using pumps, referred to as the "headworks" of the plant.
Operations to eliminate large objects and grit, often referred to as preliminary treatment, are an integral part of the treatment process. Effective removal of these solids may require a combination of unit operations such as screening, grinding, and settling.
Primary Clarifiers slow the speed of the wastewater to allow solids to settle out of the wastewater. Secondary Clarifiers are used to settle out microorganisms from the activated sludge process.
Activated sludge is a biological process whereby oxygen is bubbled through the water, providing aeration. Microorganisms or "bugs" are suspended in the wastewater by the aeration. The mixture is known as "mixed liquor." The bugs breakdown the wastes to carbon dioxide and water.
Final Clarifiers are also used to settle out microorganisms, or "bugs," from the activated sludge process. Clarifiers are usually either round or rectangular in shape.
Disinfection involves destroying harmful bacteria that are present in the wastewater. The most common method of disinfection is chlorine. Ultraviolet light and other chemicals, such as bromine, fluorine, and peroxide, are also occasionally used.
The gravity belt thickener is one way to reduce the amount of water in the bio solids before further treatment.
Anaerobic digestion is the biological degradation of organic matter in an oxygen free atmosphere. Anaerobic digestion converts the bio solids into carbon dioxide, methane, hydrogen sulfide, other gases, and water.
Solids Storage and Land Application
The end product of anaerobic digestion is a biologically stable...