Welcome Speech:
All respected Deans, Chairman of all Departments, Chairman of the Examination Committee and
Members, Supervisor, Co-supervisor, all my colleagues, beloved students welcome to my
presentation.
I would like to get permission from Chairman of the Examination Committee to start my
presentation.
The presentation topic is conversion of plastic wastes to sustainable Resources by using
Environment Friendly Technology in Bangladesh.
For the fulfill of my PhD work, I divided my full research work into 6 experiments under the
three year activities.
Environmental friendly Technique: Biodegradation is more suitable or expedient method than
physical and chemical treatment because least hazardous impacts on the environment and could
bring environment friendly technique if we identified efficient microbial strains as plastic
degrader.
Biodegradation refers to the degradation of plastics with the help of enzymes or microbes in a
specified period. It can be applied in in-situ in laboratory conditions or isolating plastic
degrading microbes from the environment. Degadation was shown by observing the
morphological changes on the PE surface using SEM and was further confirmed by the
appearance of additional carbonyl groups formation through FTIR. In addition, biodegradation
can be understood properly from weight loss reduction, loss of mechanical strength, and changes
in surface properties such morphology changes roughness, size etc. Pretreatment caused some
damage to the structure of plastic surface which assisted algal species to make biofilm and
degrade plastic more efficiently. Different microorganisms like algae, bacteria and fungi like
mucilaginous substance by algae, while bacteria and fungi produce laccases, hydrolyses, P/et-ase
which help in cleaving the polymer structure.
Plastic contains a carbon-carbon backbone structure and microbes utilize plastics as a source
offood, energy and reproduction. Microorganisms catalyses energy-producing chemical reaction
in which breakage qof chemical bonds occurs, and electron get transferred from plastics which
are further taken up my microbes.
Aerobic microbes use carbon involves breakdown of polymers into simple biodegradation
products from plastic to produce CO2, water and new cells. Anaerobic microorganisms use
carbon to produce methane, H2S, N2 and biomass.
Example of evidence: Degradation of PVC, LDPE, and HDPE through Bacillus sp isolated from
marine ecosystems. Bacillus cereus isolated from a dumping site soil sample was
documented as PE degrader.
Biological treatment of polyethylene sheet with Anabaena spiroides (blue-green alagae),
Navicula pupula (diatom) and Scenedesmus dimoorphus (green microalga) has been studied and
Anabaena found to be the efficient plastic degrader. Plastic pellets have a slower degradation rate
than other platic powder samples.
Schedule and per: I mentioned before about the two objectives under the 1st year. Here, we have
visited 16th unions in Jashore sadar upazilla to find out the plastic use diversity and sustainable
strategies and utilization of HDPE to produce plastic brick ( to determine its density, WA and
CS).
Chapter 1: I would like to talk/discuss/start the first experiment . The title of my first chapter is.
15th November in 2022, I have discussed the plastic use diversity among 16 th unions using PCA .
Now, I would like to show you the summary of my 1 st chapter where LDPE, HDPE, PET types
plastics are found at large scale. The most common management strategies are open buring about
and open dumping method.
Chapter 2: Brick production from HDPE wastes.Thsese are the experimental produce to make
plastic bricks where discared HDPE were collected from nearby hackery stall then washed
properly to remove unwanted dust and dried. Then grinding machine used to make it powder
form and water and cement mixed to certain % to get different types of bricks. Here, different %
can be used. But from the previous studies, I have gather some ideas that 10-15% increase of
plastic content, the CS increase. For the convenience of my study, I have started with the 25%
HDPE wastes.
Schedule and Per second year activities: Two objectives I have discussed. Here, from the fist
chapter we have seen about the LDPE types wastes are discarded randomly. That’s why, we
wanted to produce alternative resources from LDPE wastes that could be sustainable resources in
near future. Here density, WA, CS, SEM, FTIR, and EDX were analyzed to determine its
durability.
Apart from that PET are used at a large scale. We wanted to find out the degradation capacity of
PET bottles using microorganism (algae).
Schedule and performance of 3rd year: Under the second year, I have discussed about the PET
wastes using algae but after the use of soft drink bottles, PBCaps are discared hare and there.
Being hard polymer types plastics, I went to recycling station where PCaps are used to produce
alternative rope formation.
Viscosity is the quantity that describes a fluids resistance to flow. Lower the viscosity is and the
easier to flow.
TGA analysis: From the TGA curve, we will determine the weight loss % with the change of
temperature. In the pipe residue, in the first phase the PE about 180 0C showed the first phase of
degradation and heating value is 200c and starting temperature 250 c. In the second phase it
become degraded at 370 degree celcious. Previuos studies showed that normal PE degrade at 470
degree celcius. But discarded PE takes short time to degrade.
Compare to the diesel control with the PE diesel showed the first phase of degradation at 180 0 C
and second phase at 3100 C. where as in petrol control compare with the PE petrol showed that
control petrol showed the first phase of degradation at 120 and PE showed 110. Whereas second
phase degradation found at 280 and PE showed 310.
Overall Discussion:
Though my topic is to sustainable technology development but concluding these full works I
would like to ensure that this process could reduce the huge volume of the waste from the
environment. This will increase the physical quality of the environment if proper segregation
system is applied. The main problem is the lack of effective method and several factors can
enhance the sustainable resource formation. This tiles making process follows a local technology
but in the near future this could be eco-friendly green building materials if we could make it in
closed environment. Though Upashahar and chacra union has recycling station but in the rural
areas more training and program should be arranged to manage the waste in a proper way.
My target was to sustainable resources production
Technology- we followed the local technology
Environmental factors-source reduction through following proper separation techniques could
bring it in choosing recycling method. I my study specific types of plastic wastes are separated to
make secondary products to enhance the physical quality of environment.
Regulatory factors: In my study, recycling industries produce secondary products though
reusing the discarded plastic that could minimize the new plastic products formation.
Economic factors: In my study, choosing recycled products will minimize the cost of buying
new plastic products which ultimately give benefits for the recycled industry together with the
scavengers that will increase their income.
Social factors: In my point of view, community participation play vital role to separate plastics
wastes at the household level therefore environmental friendly plastic waste management method
could be chosen. For this, various concerned activities such as volunteers activities to give
food /tree in exchange of plastic products could be sustainable solutions.
nd
Apart from that in the 2 experiment could be used as decorative material which will ultimately
reduce the cost of making concrete tobs.
Analysis:
SEM analysis provided information about micro plastic particles morphology, surface roughness
and size. Most of the samples were lamellar or spherical shape. Some types of products has
round shape.
EDX: In combination of SEM, EDX was used to characterize the type of accumulated metals
and minerals covering the surface of the MPs particles.
FTIR: Chemical groups or functional groups (hydrophobicity) behavior indicated the Eco
toxicological effects. Previous studies showed that FTIR peaks of PE samples were observed on
the 2915-2918/cm, 2845-2850/cm, 1463-1469/cm spectrum respectively.
GC-MS: Petroleum products derived from crude oil are highly purified, and GC-MS is used to
detect contaminants, and determine if the refining process was effective . GC can analyze
compounds with a boiling point range up to and above 400°C .In this analysis, waste PE pyrolysis
gave liquid products that are very complex mixture, containing many aliphatic and aromatic
compound. The liquid and solid products from the pyrolysis of PE contains numerous
hydrocarbos,alkanes alkenes, and halogenated hydrocarbons. In GC-MS analysis, in versus of
retention time different types of hydrocarbon compounds are appeared. Retention time versus
compound determination focused on higher the retention time represents bulky or bigger the
compound size. The pyrolysis of PE has a hydrocarbon chain between C 7-C27 that indicated that
this compound is a compound mixture of kerosene and diesel fractions. Kerosen fraction has a
carbon chain length C8-C19 carbon length whereas for diesel is C7-C27
Algal growth: 4 (a) G Ulva flexuosa (MWA); 4 (b) G Chlorella vulgaris
5D- Rodophyta/Palisada perforata (MWA)(Hydrodictyon) filamentous bloom
Most prevalent algal species were found in freshwater environments includes Volvox, Chlorella
vulgaris, Craticula cuspidate,Navicula pupula, Synedra ulna, etc and in marine environments
includes Palisada perforate, Ulva flexuosa, Cladoptera herpesticaF –
Algal growth in SEM:
A1: alkali treated/biological treated (freshwater media under direct sunlight)
Observed the biofilm formation specially algae;
B1: alkali treated/biological treated (marine media under direct sunlight) Observed
the biofilm formation specially algae;
A2: alkali treated/biological treated (freshwater media under direct sunlight)
Observed the PET film by removing algal biofilm with gentle wiping and washing;
B2: alkali treated/biological treated (marine media under direct sunlight) Observed
the PET film by removing algal biofilm with gentle wiping and washing;
C1: Acid treated freshwater media under direct sunlight. Before wash (though the
algal biofilm formation was scanty) thus difference with C2 was not observed;
D1: Acid treated marine media under direct sunlight. Before wash (though the algal
biofilm formation was scanty) thus difference with D2 was not observed.
Wave Number
Sample ID Bond
(cm-1)
1800 C=O stretching
R0
2349 O=C=O stretching
R1 1800 C=O stretching
1800 Weak C=O stretching
R2
2349 O=C=O stretching
R3 1800 weak C=O stretching
2349
R4 O=C=O stretching
2349
R5 O=C=O stretching
R6 2349 O=C=O stretching
1100 Broad C-O stretching
R8 1600 Wide broad C=C stretching
2900 Weak broad N-H stretching
1800 Weak broad C=O stretching
R9
3400 Medium broad N-H stretching
