Municipal solid waste composting methods: which statements are correct about Indore and Bangalore processes and the product formed?

Introduction / Context:
Composting stabilizes organic fractions of municipal solid waste, reducing volume, odour, and pathogens while producing soil-like amendments. Two historically important Indian methods are Indore and Bangalore, each with distinct aeration and handling practices.

Given Data / Assumptions:

• Aerobic conditions imply frequent turning and oxygen supply.
• Anaerobic trench composting limits air ingress.
• End product is expected to be stable, humus-like material.

Concept / Approach:

The Indore method uses aerobic decomposition with turning and layering of refuse and night soil, encouraging thermophilic bacteria. The Bangalore method uses sealed trenches promoting anaerobic digestion; after sufficient time, the stabilized residue resembles humus, suitable for soil conditioning.

Step-by-Step Solution:

Verification / Alternative check:

Classic sanitation texts describe temperature profiles and pathogen reduction under both methods, with different retention times but similar stabilized outcomes.

Why Other Options Are Wrong:

Since (a), (b), and (c) are correct, “All of these” is the most complete answer; “None of these” is false.

Common Pitfalls:

Confusing composting (stabilization) with mere drying; assuming both methods are aerobic; overlooking retention time differences.

Final Answer:

All of these