FREE Wastewater Operator Chemistry and Biology Questions and Answers
What is the main purpose of nitrogen removal in wastewater treatment?
Excess nitrogen in treated wastewater can lead to eutrophication, which causes algae blooms, oxygen depletion, and harm to aquatic ecosystems. Nitrogen is removed through processes like nitrification and denitrification.
Which of the following is an example of a disinfection method used in wastewater treatment?
Chlorination is a common disinfection method that kills harmful pathogens in treated wastewater before it is discharged into the environment. Other methods include UV disinfection and ozonation.
What role do microorganisms play in the activated sludge process?
In the activated sludge process, microorganisms break down organic matter, reducing BOD and converting it into water, carbon dioxide, and cellular biomass.
What does Biochemical Oxygen Demand (BOD) measure?
BOD measures the amount of oxygen required by microorganisms to decompose organic material in wastewater over a specified time, typically five days. It is an indicator of the organic pollution level in water.
What is the typical pH range of wastewater suitable for biological treatment?
Microorganisms used in biological treatment thrive in a neutral to slightly alkaline pH range (6.5 to 8.5). Extreme pH levels can inhibit microbial activity and harm the treatment process.