This document discusses utilizing graphene and its composites to remove dyes from textile effluent through adsorption techniques. It begins with introducing different types of dyes and techniques for dye separation, including physical, chemical and biological methods. It then focuses on using graphene oxide and reduced graphene oxide for dye removal, explaining their structure and synthesis methods. The document discusses the adsorption mechanism and factors affecting adsorption like pH, temperature and contact time. It also examines kinetic and isotherm models for analyzing adsorption data. Finally, it reviews the adsorption capacities of different graphene-based composites and discusses conclusions and future perspectives on dye removal research.

1. Utilizing graphene and its numerous composites to
remove dyes from textile effluent by using adsorption
techniques.
Bapi Mondal
Id No:20151207052
Session: 2019-20
M.Sc. (Engineering) 3rd
Semester
Supervisor
Md. MEHEDI HASAN BABU
Dept. of Applied Chemistry and Chemical Engineering
Bangabandhu Sheikh Mujibur Rahman Science & Technology University

2. CONTENTS
2
DYE Introduction
01
Techniques of Dye separation
02
Adsorption Dye removal
03
Synthesis of Graphene and its
derivatives
04
DYE Removal Mechanism
05
Factors Affecting Adsorption
06
Kinetic and Isotherm analysis
07
Graphene based composites
adsorption capacities
08
Conclusion
09
Future Perspectives and Challenges
10

3. 3
DYE
▸ A dye is a substance that is used to
impart colors to materials like
fabrics, paper, leather, and other
things so that the colors won't be
easily changed by washing, heat,
light, or other elements to which
the material is likely to be
exposed.

4. Transition Headline
DYE Classification
DYE
Acid dye
Basic dyes
Direct dyes
Mordant dye
Sulfur dye
Vat dyes
Reactive dye
Based on
 Source of Production
 Application Methods
 Bond with fiber
 Chemical Structure
 Solubility

5. 5
Routes and fates of dyes in the environment
Fig: Routes and fates of dyes in the environment (Januário et al., 2021)

6. 6
Techniques of Dye separation
DYE Separation Methods
Physical
Adsorption Ion Exchange
Membrane
Filtration
Coagulation and
flocculation
Irradiation
Chemical
Oxidative
Process
Ozonation
Photochemical Photo catalyst
Biological
Aerobic
degradation
anaerobic
remediation
Living/dead
microbial biomass
adsorption
Fig: Various Dye separation methods (Cserhati et al., 2004)

7. 7
Graphene and its derivatives for Dye removal
Figure: Graphene Oxide Structure Figure: Reduced Graphene Oxide Structure

8. 8
Graphene and its derivatives for Dye removal

9. 9
Synthesis
Graphite
Oxidation
Graphene Oxide
Sonication/
Stirring GO Dispersion
Reducing
agent
Reduced Graphene Oxide
Reduction via
PPT, Stirring,
sonication
Fig: Synthesis of GO and rGO (Zhu et al., 2010)

10. 10
Mechanism of DYE Adsorption
 Electrostatic Interaction
 Hydrogen Bonding
 Ion Exchange
 Surface Complexation
 Van der Waals force
 π- π Interaction
Fig: Dye removal mechanism (Yagub et al., 2014)

11. 11
Mechanism of DYE Adsorption
Fig: MB Adsorption on GO (Bradder et al., 2011) Fig: MB Adsorption on rGO (Bradder et al., 2011)

12. 12
Factors Affecting Adsorption
 pH
 Temperature
 Contact Time
 Initial Dye Concentration
Fig: pH Effect on Adsorption process
(Li et al., 2013)
Fig: Contact time Effect on Adsorption process
(Sarkar et al., 2014)

13. 13
Factors Affecting Adsorption
 pH
 Temperature
 Contact Time
 Initial Dye Concentration
Fig: Temperature Effect on Adsorption
process (Lee et al., 2008)
Fig: Initial Dye Concentration Effect on Adsorption
process (Han et al., 2021)

14. 14
Kinetics of Adsorption
 Adsorption kinetics model is used to investigate the mechanism of adsorption.
 Pseudo First and Second order equation is used mainly to analyze adsorption kinetics.
Pseudo-first-order model Pseudo-Second-order model
log( 𝑞𝑒 − 𝑞𝑡) = log 𝑞𝑒 −
𝑘1
2.303
𝑡
𝑡
𝑞𝑡
=
1
𝑘2𝑞𝑒
2 +
1
𝑞𝑒
𝑡
Where,
𝑞𝑡 and 𝑞𝑒= 𝐴𝑑𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦
𝑘1 = 𝑅𝑎𝑡𝑒 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑡 = 𝑇𝑖𝑚𝑒
Where,
𝑞𝑡 and 𝑞𝑒= 𝐴𝑑𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦
𝑘2 = 𝑅𝑎𝑡𝑒 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑡 = 𝑇𝑖𝑚𝑒
 A straight line of 𝒍𝒐𝒈( 𝒒𝒆 − 𝒒𝒕) versus 𝒕 suggests
that process followed first order kinetics.
 If the second order kinetic model is applicable, a
straight line should appear on the plot of
𝒕
𝒒𝒕
vs 𝒕.

15. 15
Adsorption Isotherm
Langmuir Isotherm
1 Freundlich Isotherm
2
 The Langmuir adsorption model is predicated on the notion
that maximum adsorption corresponds to an uninterrupted
saturated monolayer of solute molecules on the adsorbent
surface.
 The Freundlich model can be applied to multilayer
adsorption with non-uniform distribution of adsorption heat
and affinities over the heterogeneous surface.
𝒒𝒆 =
𝒒𝒎𝑲𝒂𝑪𝒆
𝟏 + 𝑲𝒂𝑪𝒆
𝐥𝐧 𝒒𝒆 = 𝐥𝐧 𝑲𝒇 +
𝟏
𝒏
𝐥𝐧 𝑪𝒆
𝐾𝑎 = Langmuir constant
𝑊ℎ𝑒𝑟𝑒,
𝑲𝒇 = Freundlich constant
𝟏
𝒏
= Adsorption Intensity.
𝑊ℎ𝑒𝑟𝑒,
 R2 > 0.99 indicates that the data is fit with the Langmuir
model.
 𝑪𝒆 vs 𝑪𝒆/𝒒𝒆 should yield a straight line.  Log 𝑪𝒆 vs Log 𝒒𝒆 should yield a straight line.

16. 16
Temkin Isotherm
3 D-R Isotherm
4 Henry Isotherm
5
Adsorption Isotherm
 Indirect adsorbate/adsorbate
interactions might affect
adsorption isotherms.
 Adsorption involves multiple
layers
 Adsorption is characterized by a
uniform distribution of binding
energies.
 Used to represent the adsorption
mechanism on heterogeneous
surfaces.
 This isotherm is only applicable
for middle ranges of adsorbate
concentrations.
 This isotherm model explains a
suitable fit to adsorbate adsorption
at low concentrations.
 Describes the relationship between
the equilibrium adsorbate
concentrations in the liquid and
adsorbed phases.

17. 17
Graphene based composites adsorption capacities
243.9
183.15
49.29
357.14
423.15
276.5
MB on GO
MB on Carboxy methyl cellulose
Anionic DR 23 on GO-polyethyleneimine
MB on GO-Sodium alginate composite
MO onGO@AC
MB on GO@AC
Adsorption Capacity (mg/g)
Dye
adsorb
on
Adsorbents

18. 18
Graphene based composites adsorption capacities
Name of dye Type of Composite Removal capacity (% or mg/g)
MG GO and rGO High adsorption capacity
MB GO-MNP 99.6% Removal effectiveness
MB rGO 160 Photocatalytic activity 98.57 %
MG GO and RGO -
MB Magnetic Graphene Oxide
significant removal efficiency around
99.6 % for MB.
MB graphene oxide 243.90 mg/g adsorption capacity
FA
graphene oxide/chitosan
composite fibers
91.3 % removal efficiency
MB and MV Three-Dimensional Graphene Oxide Nanostructure
99.1% removal efficiency for MB and
98.8% of MV.
Anionic DR 23 GO-polyethyleneimine 49.29 mg/g
Indigo Carmin dye GO and Chitosan composite 90% removal efficiency
CR Graphene oxide and Fe3O4 98% removal efficiency
RhB
Nanocomposite of nickel made of graphene
oxide(Ni-GO)
90% removal efficiency

19. 19
Conclusion & Future Perspectives
Fig: Distinct adsorbents used in adsorption procedures (Dutta et al., 2021)

20. 20
References
1. Bradder, P., Ling, S. K., Wang, S., & Liu, S. (2011). Dye Adsorption on Layered Graphite Oxide. Journal of Chemical & Engineering Data, 56(1),
138–141. https://doi.org/10.1021/je101049g
2. Cserhati, E., Frogacs, E., & Oros, G. (2004). Removal of synthetic dyes from wastewater: a review. J. Environ. Int., 953–971.
3. Han, M., Xu, B., Zhang, M., Yao, J., Li, Q., Chen, W., & Zhou, W. (2021). Preparation of biologically reduced graphene oxide-based aerogel and
its application in dye adsorption. Science of The Total Environment, 783, 147028. https://doi.org/https://doi.org/10.1016/j.scitotenv.2021.147028
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M. S. (2021). Advanced graphene oxide-based membranes as a potential alternative for dyes removal: A review. Science of The Total Environment,
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adsorption of titanate nanotubes. Journal of Hazardous Materials, 150(3), 494–503. https://doi.org/https://doi.org/10.1016/j.jhazmat.2007.04.129
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7. Sarkar, C., Bora, C., & Dolui, S. K. (2014). Selective Dye Adsorption by pH Modulation on Amine-Functionalized Reduced Graphene Oxide–
Carbon Nanotube Hybrid. Industrial & Engineering Chemistry Research, 53(42), 16148–16155. https://doi.org/10.1021/ie502653t
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A critical review. Materials Advances, 2(14), 4497–4531. https://doi.org/10.1039/d1ma00354b

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QUESTIONS
???
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