NEET BIOLOGY

Detailed explanation-1: -Dissolved oxygen levels in the aeration tank must be maintained at 1-3 mg/L for effective treatment. Low levels of DO will result in the death of the microbial biomass, which is timely and expensive to reestablish.

Detailed explanation-2: -How does Aeration Work? Aeration provides oxygen to bacteria for treating and stabilizing the wastewater. Oxygen is needed by the bacteria to allow biodegradation to occur. The supplied oxygen is utilised by bacteria in the wastewater to break down the organic matter containing carbon to form carbon dioxide and water.

Detailed explanation-3: -Hydrogen peroxide can be used to increase the dissolved oxygen (DO) concentration in an aerobic bioreactor, often referred to as “DO supplementation.” Using peroxide is rarely a first choice because chemically increasing DO is more expensive than using a mechanical method (diffused aeration, mechanical mixing, etc.).

Detailed explanation-4: -Too much is not good Over-aeration wastes energy and can negatively affect process performance. Most wastewater treatment plants operate their aeration zones and aerobic digesters at 1-3 mg/L dissolved oxygen (DO). Anything more may waste DO and energy.