Global warming and the environment
pollution are critical issues which occur due to the development activities in
the world. Cigarettes also contribute to the environmental pollution mainly not
in a direct way, but due to the improper disposal of the remaining part of the
cigarette after it is used. Since cigarette butts are made of cellulose acetate
(a plastic) [5] they have poor biodegradability and it will take many years to
breakdown and also heavy metals such as Arsenic (As), Chromium (Cr), Nickel
(Ni), and Cadmium (Cd) which are trapped in the cigarette filters leach into
the soil and waterways during that process [4].
Figure 01: prepared cigarette butt for brick production [1] |
Companies produce about 6 trillion of
cigarettes every year and smokers help to make over 1200 million kilograms of
cigarette butts waste. In Sri Lanka tobacco use costs LKR 214 billion per year
(according to the statistics of 2018) in economic loss with substantial human
development losses [6]. Dr.Abbas Mohajerani who led the research project about
the cigarette butt bricks at RMIT University said that these numbers can be
increased by more than 50% by 2025 mainly due to an increase in world
population .Their research results show that if 2.5% of worlds’ brick
production with the addition of 1% of cigarette butt amount can be lead to
completely offset the annual worldwide cigarette butt production [4].
Figure 02 : Trend of smoking in Sri Lanka in Last 10 years by age groups (2009-2018) [6] |
Figure 03 : Dr. Abbas Mohajerani [4] |
Advantages
of Cigarette butt bricks
Conventional fired clay bricks are
one of the most common construction materials since the initial ages of the
building construction due to their durability, compressive strength, flexural
strength and thermal conductivity than other construction materials. Most of
the research activities have proved that incorporation of cigarette butts has
significant advantages on behalf of construction industry and also a solution
for the environmental pollution. Nowadays, engineers and architects encounter
some problems such as the thermal comfort and the noise insulation of dwelling
areas of buildings. Since they have invented some solutions such as cooling
bricks, ventilation systems and alternative materials for concrete and bricks.
Since the cigarette butts have good insulation capability, addition of them
into bricks reduce household cooling and heating demands [1]. Cigarette butts
cause to improve the noise insulation because they improve the porosity of the
bricks than the conventional bricks. In addition to that bricks with CBs
(cigarette butts) are lighter and cost effective rather than using other raw
materials for manufacturing bricks and cuts the energy needed to fire bricks by
up to 58% and that leads to reduce the embodied energy [1]. Since the density
of the filters are less than the other materials which are used in the bricks
production the overall density was reduced up to 30% [3], depending on the
percentage of cigarette butts [4]. Durability of these bricks can be increased
with the addition of filters because their biodegradability is less than other
raw materials which are used in production.
Physical properties of cigarette butt bricks
Cigarette butts have the physical
properties as follows,
• Bulk density – 1.80 𝐠𝐜𝐦−𝟑
• Apparent
porosity – 30 %vol.
• Apparent
density – 2.42 𝐠𝐜𝐦−𝟑
• Water
absorption – 16.65 %wt.
Some of the above mentioned
properties of cigarette butt bricks such as density are less than other raw
materials while properties like water absorption are higher because most of
times the filters consist of tobacco residue, sawdust and grass. Therefore, the
water absorption of the bricks increases linearly with the increase of
cigarette butt content [1].
Figure 04 : Test cigarette butt bricks with different replacement of Cigarette butts [1] |
Physical and mechanical properties of
cigarette butt bricks were tested with different percentages of CBs (2.5%, 5%,
7.5%, and 10% by weight) and with the three different mixing times to
distinguish the results compared to the conventional clay bricks. In 10% CB
bricks the dry density was decreased up to 30% and the compressive strength
decreased by 88% and the compressive strength of bricks with 1% CB was
determined as 19.53 MPa [2] and this is a suitable value for a one or two
storey buildings. Influence of the mixing time was observed by using three
different times (5, 10 and 15 minutes) for the bricks with 7.5% CB and 15
minutes brick shows 114% increment of strength and 12% increment for density
compared to 5 minutes mixing time [7]. Although the values of water absorption,
initial rate of absorption and tensile strength decreased by 22%, 29% and 5%
respectively.
As a sustainable solution
Heavy metals and other pollutants
which are trapped and immobilized in the solid block when the bricks are fired
and they cannot leach and mix with the soil and waterways anymore. In addition
to that this is a cost effective product because the cigarette butts are very
common in our surrounding and it can be supplied without any cost. Therefore,
this can be a turning point of construction industry of Sri Lanka as a
developing country.
E.M.K.G.A.D.B.Ekanayake
Department of Civil
Engineering
Faculty of Engineering
University of Sri
Jayewardenepura.
References
1) Guide,
B. and Masonry, B., 2020. Cigarette
Butt Bricks - Physical Properties And
Advantages. [online] The Constructor. Available at: <https://theconstructor.org/building/cigarette-butt-bricks/29224/>
[Accessed 19 May 2020].
2) 2020.
[online] Available at:
<https://www.researchgate.net/publication/297892222_A_practical_proposal_for_solving_the_world's_cigarette_butt_problem_Recycling_in_fired_clay_bricks>
[Accessed 19 May 2020].
3) 2020.
[online] Available at:
<https://www.researchgate.net/publication/279577246_Recycling_cigarette_butts_in_lightweight_fired_clay_bricks>
[Accessed 19 May 2020].
4) Engineersaustralia.org.au.
2020. Double Advantage To
Using Cigarette Butts To Make Bricks | Engineers Australia. [online]
Available at:
<https://www.engineersaustralia.org.au/News/double-advantage-using-cigarette-butts-make-bricks>
[Accessed 19 May 2020].
6) Tobaccounmasked.lk.
2020. Tobacco Industry Country
Profile – Sri Lanka - Tobaccounmasked. [online] Available at: <http://www.tobaccounmasked.lk/index.php/Tobacco_Industry_Country_Profile_%E2%80%93_Sri_Lanka>
[Accessed 19 May 2020].
This is awesome. An interesting topic.Progressive sustainable solution.Thank you for sharing this.
ReplyDeleteVery informative brother. Keep it up
ReplyDeleteInteresting topic. It shows that how the things can make sustainable
ReplyDeleteThanks for this article. Learnt a lot of things a great piece of share.
ReplyDelete