Activated sludge and aeration role?

Activated sludge and aeration role?

• A. A suspended-growth biological treatment system where aeration provides oxygen for microbial degradation of organics
• B. A fixed-film biological process
• C. A chemical precipitation process
• D. A thermal oxidation process

Answer: (A)

Activated sludge is a suspended-growth biological treatment. In this approach, wastewater is mixed with a concentrated culture of microorganisms that stay suspended in the liquid. Aeration—injecting air or oxygen into the tank—provides dissolved oxygen the microbes need to aerobically break down the organic pollutants. This oxygen enables the microorganisms to metabolize organics, turning them into carbon dioxide, water, and new microbial biomass. The aeration also keeps the solids in suspension and ensures intimate contact between the microbes and the pollutants, which drives efficient degradation and treatment of the wastewater. This description fits activated sludge and its use of aeration, and it differs from fixed-film processes (where microbes grow on surfaces), chemical precipitation (which relies on adding reagents to precipitate contaminants), and thermal oxidation (which uses high heat to oxidize organics).

Activated sludge is a suspended-growth biological treatment. In this approach, wastewater is mixed with a concentrated culture of microorganisms that stay suspended in the liquid. Aeration—injecting air or oxygen into the tank—provides dissolved oxygen the microbes need to aerobically break down the organic pollutants. This oxygen enables the microorganisms to metabolize organics, turning them into carbon dioxide, water, and new microbial biomass. The aeration also keeps the solids in suspension and ensures intimate contact between the microbes and the pollutants, which drives efficient degradation and treatment of the wastewater. This description fits activated sludge and its use of aeration, and it differs from fixed-film processes (where microbes grow on surfaces), chemical precipitation (which relies on adding reagents to precipitate contaminants), and thermal oxidation (which uses high heat to oxidize organics).