GATE CE 2017 Set 2 — Question 10

MCQ+2 / -0.67EasyActivated Sludge ProcessWastewater Treatment ProcessesEnvironmental Engineering

Environmental Engineering → Wastewater Treatment Processes → Activated Sludge Process

Last updated 5 September 2026

Question

The most important type of species involved in the degradation of organic matter in the case of activated sludge process is

Correct answer (B) heterotrophs Solution In the activated sludge process, the primary organisms responsible for the degradation of organic matter (BOD removal) are heterotrophic bacteria. These bacteria utilize organic carbon as both their energy and carbon source. While autotrophs (such as nitrifying bacteria) are present, they are primarily involved in the oxidation of nitrogenous compounds rather than the bulk degradation of organic matter. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (B) heterotrophs Solution In the activated sludge process, the primary organisms responsible for the degradation of organic matter (BOD removal) are heterotrophic bacteria. These bacteria utilize organic carbon as both their energy and carbon source. While autotrophs (such as nitrifying bacteria) are present, they are primarily involved in the oxidation of nitrogenous compounds rather than the bulk degradation of organic matter.

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