Plastic production from 2 million metric tonnes in 1950 to over 350 million metric tonnes by 2015
worldwide while cumulatively. The entire world has produced almost 7.8 billion metric tonnes in
2015, in other words more than one tone of plastic for every person on earth at that time.
However, it has now already crossed the 8 billion metric tonnes mark for cumulative production
of plastic. The growth is tremendous and surpasses every man made material in every sector with
few exceptions like steel and cement which are used in the construction sector and in other such
uncountable ways.
The above image depicts the statistical representation of the global plastic use.
Image courtesy: www.ourworldindata.org
According to the Centre for science and environment (CSE) this COVID-19 pandemic has also
impacted it and made plastic waste problems more frightening with increased use of disposable
and single use plastic. A recent study published in peer reviewed journal science advances states
that out of 8.3 billion metric tons of plastic that has been produced, almost 6.3 billion metric tons
have become waste. Further, only 9 %t of the total plastic waste in the world is recycled while 79
% of it accumulates in our environment. Moreover, a central pollution control board (CPCB)
report (2018-19) shows that 3.3 million metric tons of plastic waste is generated annually in
India. If this trend continues, it is estimated that by 2050 almost 12 billion metric tons of plastic
will be in the ecosystem. Further, the study has also compiled data of several polymers used in
different industries and the findings were surprising. Almost 42% of all non-fiber plastic
produced has been used in the packaging industry which is majorly composed of polyethylene
(PE), polypropylene (PP) and polyethylene terephthalate (PET). Further, most of the packaging
plastics leave the use in the same year they are produced which is not the case in other industries.
This results in making the packaging industry the major contributor of the plastic waste.
Most of the produced plastic lies under single use and disposable plastic category which
eventually results in trash. Although plastic waste is India's and world's one of the most
challenging environmental issues. But can we solve it?
The traditional solution was to use a thermo-mechanical recycling process. Recycle the major
contributor such as PET and use recycled products. But there are some limitations of the
traditional method, only clear plastic can be recycled in closed loops and every cycle there is a
loss of quality which makes it not so cost effective and difficult to recycle and may be harmful to
the environment directly or indirectly.
Here comes the biotechnology addressing the problem with the development of bio plastics in
order to solve it. Bio plastics are made of renewable sources such as plants, vegetables,
agricultural waste, etc. These are biodegradable, and have less carbon footprints than single use
plastics. Biotech companies such as Truegreen, based in Ahmedabad, make bio plastics and take
a step towards sustainability. Use of bio plastics instead of single used plastic seems promising
but it is not cost effective yet. And it is for this reason that it is bit difficult to use it in industries
such as the packaging industry.
Another solution that biotechnology has provided is enzyme based recycling which was quite
difficult to use a few years back on a large scale due to inefficiency. But the development of a
newly engineered PET depolymerase which is capable of breaking down a minimum 90% PET
in just over 10 hours makes it a doable solution for us. Further, from monomers generated from
this enzymatically depolymerized PET waste we can synthesize biologically recycled PET which
has the same properties as petrochemical PET. Moreover, with this enzymatic method we can
recycle not only clean plastics but also the complex and soiled plastics which are not the case in
traditional recycling.
In the near future with the help of these new developing methods, we may be able to reduce the
plastic waste and introduce recycled plastic waste into the industries which eventually decrease the production of the non-biodegradable plastic.
Aman Chamadiya
Department of Biochemistry and Biotechnology
St Xavier’s College, Ahmedabad
References:
1. R. Geyer, J. R. Jambeck, K. L. Law, Production, use, and fate of all plastics ever made.
Sci. Adv. 3, e1700782 (2017).
2. Tournier, V., Topham, C.M., Gilles, A. et al. An engineered PET depolymerase to break
down and recycle plastic bottles. Nature 580, 216–219 (2020). https://doi.org/10.1038/s41586-020- 2149-4