Transformation means a process of reduction of waste by volume and weight and recovering the energy from them.

Typically waste transformations are used to improve the efficiency of solid waste and management systems, to recover reusable and recyclable materials, and to recover conversion products and energy which include the following method they are -

• 1) Physical transformation
• 2) Chemical transformation
• 3) Biological transformation

1. Physical transformation

Physical transformations of solid waste typically involve a change of phase. To reduce the volume and to recover conversion products, the principal physical processes used to transform municipal solid waste include:

• a) component separation
• b) Mechanical volume reduction
• c) Mechanical size-reduction

All three of these processes are often classified as volume reduction processes

2. Chemical transformations

Chemical transformations of solid waste typically involve a change of phase. To reduce the volume and to recover conversion products, the principal chemical processes used to transform municipal solid waste include:

• a) Combustion
• b) Pyrolysis
• c) Gasification

All three of these processes are often classified as thermal processes

3. Biological transformation

The biological transformations of the organic fraction of Solid Waste may be used:

• a) to reduce the volume and weight of the material
• b) to produce compost
• c) to produce methane and include: aerobic composting, low-solids anaerobic digestion, high-solids anaerobic digestion