Microbes in Sewage Treatment — Prelims Strategy

Prelims Strategy

To effectively tackle NEET questions on 'Microbes in Sewage Treatment', a systematic approach is essential. Firstly, understand the overall flow diagram of a sewage treatment plant, from primary to secondary treatment and sludge digestion.

Visualize each step. Secondly, differentiate clearly between primary and secondary treatment: remember primary is physical (screening, sedimentation), while secondary is biological (microbial action).

Focus on the role of microbes: know that aerobic microbes form 'flocs' in aeration tanks to reduce BOD, and anaerobic microbes in sludge digesters produce 'biogas'. Understand the concept of BOD (Biological Oxygen Demand) – what it measures, why it's important, and how it's reduced.

Pay attention to key terms like 'activated sludge' and its recycling. For numerical problems, practice simple percentage calculations related to BOD reduction. When answering MCQs, carefully read each option.

Trap options often confuse primary and secondary treatment roles, or aerobic and anaerobic conditions. Always link the process to its environmental significance. Drawing a simple flow chart during revision can greatly aid recall.