Clean as few non-renewable resources as possible for

Clean technology, or also
known as Cleantech, is used to define a set of technologies that can reduces or
improves the use of natural resources, while at the same time reducing the harmful
effect of technology has on the earth and its ecosystems (Pirolini, 2015). Pirolini
(2015) also stated that, cleantech also used to describe products, processes or
services that reduce waste and require as few non-renewable resources as
possible for example, clean coal technology. Examples above explains how clean
technology is a part of the solutions and have a positive advantage in relation
to climate change and sustainable development. The investment community takes
clean technology as solutions to be economically practical and have the
potential to be profitable. On the other hand, the environmental groups and
governments focuses on the beneficial impacts of clean technology has on the
environment solutions and feels that it is more important than current
profitability calculations.

 

Solid waste management

 

            The
problems related to the wide consumption and depletion of natural resources and
the increasing output of wide-ranging types of waste are becoming more serious
nowadays. This can be caused by the economic development, industrialization and
increasing population (Ministry
of the Environment Japan, 2012). Therefore, the management of solid
waste has to be efficient enough to solve this problem other than limiting the
consumption of natural resources. Ministry of the Environment Japan has
invented some of leading Japanese waste disposal and recycling technologies
which is a cleantech to overcome this problem. The cleantech is used for the
solid waste management from the collection and transportation of   waste to the disposal in landfills.

 

            Under
the collection and transport of waste, the Ministry of the Environment Japan
set up waste transfer stations to transfer from small or medium sized garbage
trucks to larger trucks. The transfer station method commonly adopted in Japan
is the compactor container transfer station. The compactor container able to
compress three of 2 ton trucks into only one container. The improvement in the
efficiency of collection and transport can directly reduce the cost while
maintaining or improving services to residents. Therefore, according to Ministry
of the Environment Japan (2012), transfer of waste to larger trucks at
transport stations improves transport efficiency, reduces cost, reduces fuel
consumption, and reduce CO2 emissions which contribute to the prevention of
global warming.

 

            Another
cleantech used in Japan’s solid waste management is by incinerating garbage. It
is well known that incinerate municipal waste can generate SOx, HC1, NOx, smoke
and dioxin. Therefore, Ministry
of the Environment Japan has taken measures to prevent and reduce
dioxin generation by increasing furnace temperature when starting operation,
and maintain high temperature at the end of operation to completely burn waste.
Moreover,  exhaust cooling is also installed
to prevent the re-synthesis of dioxin, application of bag filters installed to
eliminate dioxin contained in smoke systematically, and the activated coal is
developed, to adsorbs and eliminates dioxin in exhaust fumes and a catalyst
that decomposes dioxin (Ministry
of the Environment Japan, 2012).

 

            Next,
in Japan, they use sanitary disposal technology with high-environment
preservation capability to dispose medical wastes. The risk of contaminated waste being
mixed with general waste increase the possibility of the spread of
contamination and a simple incineration of medical waste may generate hydrogen
chloride and dioxin. Thus, the Ministry of the Environment Japan set up
incinerator specifically for medical waste are to reduce dioxin content in the
gas emissions. In the incinerator, waste is broken down and fully disinfected
so that contagious pathogens cannot spread through the air. Next, gas
temperature in the incinerator is maintained at 800°C or higher, and when the
treatment capacity of the incinerator is less than 2t/hour, dioxin should be
5ng-TEQ/m3 or lower (Ministry
of the Environment Japan, 2012). The
collected bottles are cleaned, and caps and labels taken off to improve their
quality. The bottles are then compressed, bound and passed on to reproduction
contractors.

 

Under the 3R policy (Reduce,
Reuse, Recycle), Japan has been collecting PET bottles, food trays, and cans
separately for reuse as recycle resources in the manufacturing of new products.
Relatively high-grade PET bottles are collected and remade into PET bottles or
other products with the high technology possessed by Japan. The collected
bottles are cleaned, and caps and labels taken off to improve their quality.
The bottles are then compressed, bound and passed on to reproduction
contractors to make recycle products such as shirts, carpets, bottles for
detergents, cosmetic containers, paper packs, containers and etc. To make new
PET bottles, collected bottles are washed, dissolved under high temperature and
filtered to reproduce high quality plastic resin. New PET bottles are made
using 50% recycled resin produced through the material recycle method and 50%
recycled resin produced through the chemical recycle method, for 100% recycled PET
bottles for beverages. Ministry
of the Environment Japan (2012) reported that this reproduction led to
an approximately 90% reduction in the use of petroleum-derived resources and a
60% reduction in CO2 emission.

 

Lastly, the last resort for
solid waste management is by disposal in landfill. Japan has invented a landfill
disposal technology that enables the stabilization of waste in a short time
using a semi-aerobic landfill which is sanitary and has no environmental
problem. The semi-aerobic landfill technology able to stabilize landfill sites rapidly
after the land has completed its role as landfill, allowing it to be used for other
function such as parks and open space for sports. In the semi-aerobic landfill,
 Ministry
of the Environment Japan (2012) stated that leachate collecting pipe is
arranged at the bottom of the landfill to remove leachate from the landfill, so
that leachate will not remain where waste is deposited and natural air is
brought in from the open pit of the leachate collecting pipe to the landfill
layer, which promotes aerobic decomposition of waste. This technologies can
effectively prevent global warming by enables early stabilization of waste,
prevents the generation of methane and also greenhouse gases.

 

Soil & ground water remediation

 

            According
to EPA (2017), one of the method to clean up or remediate contaminated soil and
water is by using nanotechnology. Nanotechnology can be defined as the
understanding and control of matter at dimensions between approximately 1 and
100 nanometers, where unique occurrences allow different applications (Otto et al., 2008). Nano-sized particles have large
surface areas relative to their volumes and may have enhanced chemical and biological
reactivity. Nanotechnology holds promise in remediating sites cost effectively
and addressing challenging site conditions, such as the presence of dense nona-aqueous
phase liquids (DNAPL). Therefore, nanomaterials have been used to remediate
contaminated groundwater and subsurface source areas of contamination at
hazardous waste sites.

 

            Metallic
substances is used due to its properties such as elemental iron to degrade
chlorinated solvent plumes in groundwater and one of the example of an in situ
treatment tools for chlorinated solvent plumes is, the installation of a trench
filled with macroscale zero-valent iron to form a permeable reactive barrier
(PRB) (ITRC, 2005). Studies have found that, nanoscale zero- valent iron (nZVI)
may prove more effective and less costly than macroscale ZVI because it can degrade
trichloroethene (TCE), a common contaminant at Superfund sites, more rapidly
and completely than larger ZVI particles. Also, nZVI can be injected directly
into a contaminated aquifer, eliminating the need to dig a trench and install a
PRB. Research indicates that injecting nZVI particles into areas within
aquifers that are sources of chlorinated hydrocarbon contamination may result
in faster, more effective groundwater cleanups than traditional pump-and-treat
methods or PRBs (Otto et al., 2008).

 

            Nanoscale
iron particles can be altered to include catalysts such as palladium (Pd),
coatings such as polyelectrolyte or triblock polymers or can be encased in
emulsified vegetable oil droplets (Otto et al., 2008). Otto et al. (2008) further stated that to remediate the contaminations
in soil and groundwater, bi-metallic nanoscale particles (BBNPs) have been used
and it contain particles of elemental iron or other metals in conjunction with
a metal catalyst, such as platinum (Pt), gold (Au), nickel (Ni), and palladium.
The combination of metals in the BBNPs cause the increase of kinetics of the
oxidation-reduction (redox) reaction, thus catalyzing the reaction.

 

One of the example of
project that used nanotechnology and showed positive results at full scale is a
former fill area in Hamilton Township, New Jersey, which was treated with a
nanoiron water slurry. The groundwater at the site was contaminated with TCE
and associated daughter products, with an initial maximum volatile organic
compound (VOC) concentration of 1,600 micrograms per liter (?g/L). The nZVI was
then injected in two phases over a total of 30 days. The project reported that
post injection monitoring indicated a decrease in the concentration of
chlorinated contaminants of up to 90 percent. Currently the site is in the
monitoring phase (Varadhi, 2005).

 

            Otto et al. (2008) also reported that previous research has
found that nanoparticles such as nZVI, emulsified zero-valent iron (EZVI) and bi-metallic
nanoscale particles (BNPs) may effectively reduce contaminants such as perchloroethylene
(PCE), TCE, cis- 1, 2-dichloroethylene (c-DCE), vinyl chloride (VC), and
1-1-1-tetrachloroethane (TCA), and also polychlorinated biphenyls (PCBs),
halogenated aromatics, nitroaromatics, and metals such as arsenic or chromium. Nanoparticles
can be highly reactive due to their large surface area to volume ratio and the
presence of a greater number of reactive sites. This allows for increased contact
with contaminants, thus resulting in rapid reduction of contaminant
concentrations.

 

CONCLUSION

 

            Cleantech is a new technology and related business models thus
offering competitive returns for investors and customers while also providing resolutions
to worldwide challenges. Cleantech is focussed by market economics therefore
offering greater financial upside and sustainability. The concept of cleantech
embraces a diverse range of products, services, and processes across industry
that are designed to deliver superior performance at lower costs, reduce or
eliminate negative environmental impact, improve the productive and responsible
use of natural resources.