What is the primary purpose of biomining in the closure of old dumps?
- ATo use the stabilized matter as organic manure
- BTo reduce the volume of waste before cappingCorrect
- CTo prevent groundwater contamination by removing the toxic material
- DTo extract valuable material from the waste
Solution
Concept
Biomining excavates old dumps and sorts the waste to recover land and reduce volume.
Step-by-step solution
1. Biomining means excavating and processing old waste with screening and sorting. 2. Stabilized fine material, recyclables and RDF are separated. 3. The remaining residue is much less in volume. 4. This residue is then capped or landfilled, so volume reduction before capping is the main aim.
Explanation
Biomining is done to reclaim land and cut down the waste volume at old dumps. The sorted material is reused and only a small residue is left for capping.
Why the other options are wrong
A: manure is only a by-product. C: groundwater protection is a result, not the main step. D: extracting valuables is secondary.
Shortcut
Old dump + biomining = volume reduction and land recovery.
Common mistake
Choosing D because biomining sounds like mining of valuable material.
Correct answer: B) To reduce the volume of waste before capping