Table 2: Comparison of Cradle-to-Grave and Cradle-to-Cradle concepts
Cradle-to-Grave
Final destination of the generated waste is the
disposal site
Objective: Minimisation of waste
Use of pollution control technologies for waste
treatment
Cost minimisation
Cradle-to-Cradle
Final destination of the generated waste is the input
of another industry
Objective: Adding value to the waste
Development of network to utilise the waste as
inputs for other process/industry
Revenue increase
CRADLE-TO-CRADLE
The Cradle-to-Cradle approach for SW
management originated from the concept of zero
emission. Instead of sending the generated SW for
final disposal (termed as ‘grave’), this approach
suggests the possibility of using SW as resources
to replace raw materials or inputs for another
process or industry (termed as ‘cradle’). The two
main benefits of this approach are the reduction
of waste volume required for final disposal (or in
other words, prolonging the lifespan of secure
landfill), and resources conservation.
In the traditional waste management model,
residual waste presents after making the best
efforts of minimise the waste generation. The
zero-emission concept is an environmental goal
to eliminate waste from the industry by shifting
the traditional industrial model to an integrated
system, where the residual waste from one industry
is the resource for another industry. Networking
between industries is the key of success for this
concept. The industries need to be reorganised
in such a way to match one industry’s waste with
the input requirement of another industry. Table 2
indicates the comparison of Cradle-to-Grave and
Cradle-to-Cradle concepts.
WASTE MANAGEMENT HIERARCHY
The waste management hierarchy is globally used
as a principle in developing waste management
strategy. Article 4 in EU Directive 2008/98/EC
stated that the waste management hierarchy
should be applied as priority order in waste
prevention and management legislation policy.
The hierarchy starts with prevention followed by
preparing for re-use, recycling and disposal.
REDUCE
REUSE
RECYCLE
RECOVER
DISPOSE
Waste Management Hierarchy
LEAST
PREFERABLE
Reduce
Reduce (or called prevention) is defined as
measures taken before a substance, material or
product has become waste.
Reuse
Reuse is defined as an operation in which the
products or components (which are not waste) are
used again for the same purpose for which they
were conceived. It is practiced widely in industries
that utilise high-temperature processes. An
example is using cooling water via recirculation as
a cooling tower freshwater, or for other purposes
such as cleaning and fire protection.
Recycling
Recycling is defined as a recovery operation in
which the waste materials are reprocessed into
27