INGENIEUR
products, materials or substances whether for the
original purpose or alternative function. Recycling
includes the reprocessing of organic material
but does not include energy recovery and the
reprocessing into fuels or materials meant for
backfilling operations. Recycling also includes
reclamation or the use of a waste for a different
purpose than originally intended. A material is
reclaimed if it is processed for recovery of useful
product or if it is regenerated. Common SW
reclamation activities involve recovery of metals.
For example, the recovery of lead from car battery.
Recovery
Recovery is defined as the operation in which the
waste could serve a useful purpose by replacing
other materials which would otherwise be used
to fulfill a particular function or being prepared
to fulfill the said function in the plant or wider
economy. Energy recovery in the form of heat
or electricity from SW incineration is a clear-cut
example.
Disposal
Disposal is the last option, where the remaining
waste generated from the aforementioned stages
is sent to the secure landfills. Landfill is the most
traditional yet least desirable option for waste
treatment because of the many potential adverse
impact.
DIFFERENCE BETWEEN SECURE
LANDFILL AND SANITARY LANDFILL
SW can only be disposed at secure landfill while
the sanitary landfill is catered for the disposal
of municipal solid waste. Stringent design
requirements such as double-liner system and
extensive leachate treatment, as well as operating
procedures are imposed for secure landfills to
ensure maximum safety to the environment.
DISCUSSION ABOUT RECOVERY AND
DISPOSAL
Incineration, where the waste is heated at above
850°C under controlled conditions, converts
waste into ash and flue gas. After the incineration,
only the solid residue, that is ash, will be sent
for landfilling. Thus, the incineration effectively
reduces the mass and volume of the waste prior
to final disposal. Even though waste incineration
does not replace landfills in waste management
hierarchy, the waste volume reduction during
incineration is vital to increase the lifespan of
landfills.
According to EU Directive 2008/98/EC,
incineration without energy recovery is considered
as disposal, while incineration with energy recovery
(Waste-to-Energy in the form of heat or power) can
be considered as recovery process. The directive
further defined that only waste incineration with
energy recovery efficiency above 60% can be
fitted under recovery. One of the energy recovery
examples in Malaysia is the clinical waste
incineration plant operated by Edgenta Mediserve
Sdn Bhd (EMSB). Clinical waste is one of the
SW with code SW 404. The high temperature
used during incineration destroys biological and
chemical hazards, thus effectively reducing the
risks posed by the SW. EMSB provides clinical
waste management, together with linen and
laundry services for hospitals. The EMSB facilities
at Kamunting, Perak consists of clinical waste
incinerators and a laundry plant for cleansing
and janitorial, linen and laundry services. The
incinerators produce hot flue gas, which is used
for generation of saturated steam for the laundry
operation. On the other hand, the ash produced
from the incineration is sent to secure landfills for
disposal.
It should be noted that although landfilling is
the least preferable method in waste management,
it cannot be eliminated or replaced. The landfill
option co-exists with other waste management
methods, and plays an important role of receiving
the residual waste from the industry after waste
reduction, reuse, recycling and recovery.
SCHEDULED WASTE GENERATION
SOURCES
In any industry, raw materials will be processed in
order to make a product. Consequently, pollution
generation during the production process, either in
wastewater, gas emission or solid waste. Figure 2
illustrates the generation of SW from a production
28 VOL 82 APRIL-JUNE 2020