Microbes in Sewage Treatment — Prelims Strategy

Prelims Strategy

To excel in NEET questions on 'Microbes in Sewage Treatment,' adopt a multi-faceted strategy. Firstly, clearly understand the sequence of treatment stages: primary (physical), secondary (biological), and anaerobic sludge digestion.

Memorize the key processes and what happens in each. Secondly, focus on the specific microbial roles: aerobic bacteria and fungi forming flocs in aeration tanks during secondary treatment, and anaerobic bacteria (methanogens) in sludge digesters producing biogas.

Understand the conditions under which these microbes thrive (aerobic vs. anaerobic). Thirdly, grasp the concept of Biological Oxygen Demand (BOD) thoroughly – what it measures, why its reduction is important, and how it changes across treatment stages.

Remember that a high BOD indicates high pollution. For numerical questions, practice simple percentage calculations related to BOD reduction. Pay attention to trap options that might confuse primary with secondary treatment, or aerobic with anaerobic processes.

For instance, an option suggesting microbial degradation in primary treatment is a common distractor. Always read the question carefully to identify if it's asking for a correct or incorrect statement.

Visualizing the process flow can also aid in better retention.