heavy metal removal from wastewater

Adsorption of Cd2+ and Pb2+ from wastewater using surfactant-modified chitosan beads
and their subsequent use for dye removal
School of Environmental Science and Engineering,
Indian Institute of Technology, Kharagpur-721302, India
(e-mail: pal.preiti@iitkgp.ac.in)
Supervisor: Prof. Anjali Pal (anjalipal@civil.iitkgp.ac.in)
Indian Institute of Technology Kharagpur,
India, 721302
Synopsis Seminar
1
Preeti Pal

Cadmium and lead in environment
2
Cadmium Lead
Properties Highly toxic
Carcinogenic
Non degradable
Persistent metal
Corrosion resistant
Very stable
Highly toxic
Carcinogenic and
non degradable
Uses PVC products
Alloys
Color pigments
Ni-Cd batteries
Pb-acid batteries
Color pigments
Alloys
Anticorrosion agent
Health
effects
Liver
Kidney
Respiratory system
Skeletal system
Brain
Liver
Kidney and ones
Developing fetus
Half-life In kidney 38 years
liver 19 years
Limit :0.003 mg/L
(WHO)
1 month in blood,
1-1.5 months in soft
tissue,
About 25-30 years in
bone
Introduction Methodology
Results and
Discussion
Inference from
the study
Conclusions Acknowledgement References
(Ades and Kazantzis 1988; Elinder et al. 1985; WHO, 2008; USEPA, 1999, ATSDR, 2010)
Cosmetics
Drinking water
Paints
Food containers
Exposure of cadmium and lead occurs through
4000-13000
tons Cd/year
agricultural
field and
natural water
bodies
(Center for food safety, cadmium-in-rice2013)

Speciation of cadmium and lead in water
3

4
Dyes used in this study
Results and
Discussion
Summary of the
results
Conclusions Acknowledgements References
Crystal violet
Methylene blue
Tartrazine
Main uses: Laboratory, textiles, leather and food processing
Reduction of Tartrazine may produce
sulphonated aromatic amines compounds
• Hyperactivity
• Asthma
• Migraines
• Thyroid cancer
• Causes respiratory tract irritation.
• Nausea, vomiting, diarrhea, and
gastritis.
• Causes skin irritation.
• Causes eye irritation and possible
injury.
• Carcinogen and mutagen
• Persistent in environment for a long
period of time
• Pose toxic effects and act as a poison
• Potent carcinogen
• Tumor growth in some species of fish
Uses: mutagenic and bacteriostatic
agent in medical antimicrobial agent
to prevent the fungal growth.
Lethal dose
(human) 50-500
mg/kg (for 70 kg
person).
14 ug/kg
(0.014 mg/kg)
>7 mg/kg can
cause
restlessness
Source: U.S. National Library of Medicine.
Crystal violet
Methylene blue
Tartrazine

U.S. chitosan market revenue, by
application, 2014 - 2025 (USD million)
Data source: https://www.grandviewresearch.com/industry-analysis/global-chitosan-market 5
Chitosan
Special characteristics
Hydrophilicity
Biocompatibility
Biodegradability
Nontoxicity
Adsorption properties
Poly-functionality
•Chitosan is second abundant
biopolymer after cellulose.
•Prepared by chitin deacetylation,
which is obtained by treating the
shrimp and crab shells with
sodium hydroxide.
Structural properties
A linear polysaccharide
composed of β (1-4)linked
D-glucosamine and N-
acetyl-D-glucosamine
Presence of –OH and –NH2
groups make it feasible for
modifications.
Introduction
Literature
review
Results and
Discussion
Summary of the
results
What? Why?

Gel
beads
Chitosan and
its different
forms
Nano-Fibres
Flakes Fibers Membranes
Nano-
particles
Powder
Introduction
Literature
review
Results and
Discussion
Summary of the
results

7
Modification of
chitosan beads using
surfactants
Binding of SDS with Chitosan:
• The cooperative binding (above CMC)
• Anti-coopertaive binding (between CAC and CMC)
• Non-cooperative binding (below CAC)
(Bain et al., 2010; Guzmán et al., 2016)
An anionic surfactant
Used in
• Cosmetics
• Pharmaceutical
• Food products
• Industrial cleaning
• Laundry
• Dairy processing
Can cause
• Skin and eye irritation
• Can hinder the normal activities of
macromolecules such as peptides, enzymes, and
DNA.
Tolerance limits for inland
surface waters and drinking
water: 1.0 mg/L (IS
10500:2012)
Industrial Discharge limit: 15
mg/L (Environment Protection
(Standards for effluent
discharge) Regulations
2003.
Pal and Pal, 2018a
Introduction
Literature
review
Results and
Discussion
Summary of the
results
Sodium dodecyl sulfate
(SDS)

8
Raw Material Adsorbent prepared Contaminant removed Adsorption capacity (mg/g) Reference
Chitosan CS beads Ni2+ 10.0 (Kongarapu et al., 2017)
Surfactant Modified PRECS 18.56
POSTCS 37.82
Chitosan CS beads MG 171.35 (Das and Pal, 2016)
Surfactant Modified CSC 239.47
SPEC 352.52
CSCS 359.42
Raw CS beads CR 162.32 (Chatterjee et al., 2009)
Surfactant Modified CS/CTAB CR 352.5
Chitosan CB MB 99.01 (Chatterjee et al., 2011)
Surfactant Modified CSB 226.24
Surfactant Modified CS/SDS CR 1490.65 (Lin et al., 2017)
CS/SDOS 1539.98
CS/SDBS 1637.58,
CS/AOT 1766.20
CS/DTM-12 1732.89
Raw Wheat straw MB 55.0 (Azadeh et al., 2015)
Surfactant Modified SDS modified wheat straw 126.60
Laterite soil SDS modified laterite soil Cu2+ 185.0 (Pham et al., 2017)
Hydrotalcite-iron oxide
magnetic
organocomposite
HT-DS/Fe MB 110.05 (Miranda et al., 2014)
HT-DSB/Fe 94.69
Adsorption capacities of some of the raw materials and their surfactant modified
forms.
Introduction
Literature
review
Results and
Discussion
Summary of the
results

9
Objectives
• Preparation and modification of chitosan beads for removal of Cd2+ and Pb2+ from
aqueous medium by surfactant-modified chitosan beads as adsorbent.
Results and
Discussion
Summary of the
results
Conclusions Acknowledgements
Objectives
• Column study using Cd2+ as model contaminant and surfactant-
modified chitosan beads as adsorbent.
• Application of the prepared adsorbent for Cd2+ adsorption
from mixed wastewater.
• Further use of these waste beads to remove dyes such as methylene blue,
crystal violet and tartrazine.

10
Chitosan (CS) beads preparation
Preparation of surfactant-modified chitosan (SMCS) beads
Characterization of SMCS beads
•SEM (Scanning electron microscopy)
•EDAX
•FTIR (Fourier transform infrared
spectroscopy)
•XRD (X-ray powder diffraction)
Removal of heavy
metals
Applications of SMCS beads
Removal of Cd2+
Removal of Pb2+ Removal of Cd2+ from
mixed wastewater
Cd2+ adsorption
in continuous
column
CdL-SMCS beads PbL-SMCS beads
Methylene blue removal Crystal violet and
tartrazine removal
Flow chart of the work done
Results and
Discussion
Summary of the
results

11
Preparation and characterization of CS and SMCS beads

12
Flow chart showing the preparation of CS and SMCS beads
Results and
Discussion
Summary of the
results
CS powder= 3 g/ 250 mL of acidic solution
SDS concentration= 6000 mg/L
Beads taken for weighing 50
Wet weight per bead 2.43× 10-2 gm
Dry weight per bead 4.5 × 10-4 gm
Moisture content (%) 97.71%
% weight (100- moisture
content)
2.09%
Figure: Photograph of the SMCS beads prepared.

13
CS beads
SDS>>CMC
SMCS bead
SDS solution
Step-1
CS powder
Step-2
Metal ion solution
Added to
SDS solution
Step-3
Pictorial presentation of formation of CS beads to metal loaded-SMCS beads
Results and
Discussion
Summary of the
results
MB, CV and TZ removal by
metal loaded-SMCS beads
Step-4
Metal loaded-SMCS bead
SMCS bead after
metal adsorption

14
Metal loaded SMCS
beads
SMCS beads
Removal of Cd2+
Removal of Pb2+
Pictorial presentation of the work done
Results and
Discussion
Summary of the
results
Metal ions
Recovery of adsorbent
and adsorbate
Desorption
Reuse of metal
loaded-SMCS beads
for dye removal
Tartrazine (TZ)
Reuse for other
purpose
Methylene blue (MB)
Crystal violet (CV)

15
Application of SMCS beads for cadmium ion (Cd2+) removal from
aqueous medium

16
0
20
40
60
80
100
120
0
10
20
30
40
50
60
70
80
90
100
10 20 30 40 50 100
%
Removal
Cadmium conc. (mg/L)
CS beads (% R)
SMCS beads (% R)
CS beads (mg/g)
SMCS beads (mg/g)
Adsorbate
adsorbed
(mg/g)
Comparison of Cd2+ removal performance by CS and SMCS beads
Figure: Comparison of Cd2+ removal by CS and SMCS beads.
Cd conc. (mg/L) 10 20 30 40 50 100
CS (% R) 40.08 35.9 22.89 17.35 15.84 14.66
SMCS (% R) 95.01 93.79 90.04 79.45 72.78 59.79
CS (mg/g) 7.41 13.05 12.48 12.62 14.40 29.98
SMCS (mg/g) 17.27 34.10 49.60 54.87 71.67 108.72
Table: Comparison of Cd2+ removal performance by CS and SMCS beads.
Results and
Discussion
Summary of the
results

17
0
10
20
30
40
50
60
70
80
90
100
5 30 60 120 240 480 720 1440 2160 2880
%
Removal
Time (min)
0
20
40
60
80
100
120
140
5 30 60 120 240 480 720 1440 2160 2880
Adsorbate
adsorbed
on
SMCS
beads
(mg/g)
Time (min)
10 mg/L 20 mg/L 30 mg/L 40 mg/L 50 mg/L 100 mg/L
Kinetic study
Figure: Effect of contact time on the % removal (a) and
adsorption capacity (b) for Cd2+ adsorption by SMCS
beads. Dose (0.45 g/L).
[Cd] % R
10
>90
20
30
~80
40
50
>50
100
(b)
Results and
Discussion
Summary of the
results

18
Cd2+ Conc.
(mg/L)
Pseudo first order Pseudo second order
qt (mg g−1) k1 (min−1) R2 qt(mg g−1) k2 (g mg−1 min−1) R2
10 14.01 0.0023 0.948 22.73 4 x10-4 0.997
20 27.183 0.0019 0.966 45.45 2.12 x10-3 0.995
30 44.625 0.0017 0.982 66.66 1.2 x10-4 0.993
40 46.279 0.0021 0.928 83.33 1.34 x10-4 0.997
50 56.042 0.0016 0.982 100.00 8.07x10-5 0.991
100 52.56 0.0069 0.865 125.00 2.82 x10-4 0.997
Table: Parameters of the kinetics study of Cd adsorption onto the SMCS beads.
0
20
40
60
80
100
120
0 500 1000 1500 2000 2500
t/q
t
(min
g/mg)
Time (min)
10 mg/L 20 mg/L
30 mg/L 40 mg/L
50 mg/L 100 mg/L
Figure: Pseudo-second order model for Cd2+ adsorption onto
SMCS beads.
0
20
40
60
80
100
120
140
0 300 600 900 1200 1500 1800 2100 2400 2700
q
t
(mg/g)
Time (min.)
Cal (10 mg/L) Expl (10 mg/L) Cal (20 mg/L) Exp(20 mg/L)
Cal (30 mg/L) Exp(30 mg/L) Cal (40 mg/L) Exp (40 mg/L)
Cal (50 mg/L) Exp (50 mg/L) Cal (100 mg/L) Exp (100 mg/L)
Figure: Plot of qt vs. t for experimental data and theoretical data
based on the pseudo-second order model.
Theoretical and
experimental
curve fitting
Results and
Discussion
Summary of the
results

19
0
20
40
60
80
100
120
0.09 0.225 0.36 0.45 0.675 0.9 1.125 1.35
%
Removal
Dose (g/L)
10 mg/L
40 mg/L
100 mg/L
0
10
20
30
40
50
60
70
80
90
100
4 5 6 7 8
%
Removal
pH
% R
Fig: Effect of dose on the % removal of Cd2+
by SMCS beads (contact time: 10 hours).
Fig: Effect of pH on Cd2+ removal with 30 mg/L
Cd2+ conc., dose:0.45 g/L, time: 10 h.
Optimum dose- 0.45 g/L
Optimum pH- 7
(For standard deviation calculation ;n= 3)
100 mg/L>50 % removal
10-40 mg/L >80 % removal
30 mg/L ~90 % removal
Adsorbent dose and pH study
Results and
Discussion
Summary of the
results

20
Isotherm models R2 Linear equation Equation
Langmuir qm (mg/g) 125 0.996 Ce/qe = 1/(qm.KL) + (1/qm).Ce y = 0.008x + 0.013
KL (L/mg) 0.615
Freundlich KF(mg/g)(L/mg)1/n 46.94 0.855 ln qe = ln KF + (1/n) ln Ce y = 0.2829x + 3.8496
1/n 0.282
0
1
2
3
4
5
6
-2 -1 0 1 2 3 4 5
ln
(qe)
ln (Ce)
(b)
Fig: (a) Langmuir, (b) Freundlich adsorption isotherm for removal of Cd2+ using SMCS beads.
Table: Values of isotherm constants for Langmuir and Freundlich isotherms and their corresponding R2 values.
0.00
0.10
0.20
0.30
0.40
0.50
0 10 20 30 40 50
C
e
/q
e
(g/L)
Ce (mg/L)
(a)
Equilibrium isotherm study
Results and
Discussion
Summary of the
results

21
Initial conc. (mg/L) Temperature (K) ΔG (kJ/mol) ΔH (kJ/mol) ΔS (kJ/mol K) R2
20
293 -5.63
39.076 0.152 0.970
303 -6.76
313 -8.69
30
293 -4.61
38.157 0.146 0.997
303 -6.18
313 -7.52
40
293 -2.57
33.852 0.125 0.900
303 -4.45
313 -5.04
Table: Values of thermodynamic parameters for adsorption of Cd2+ onto SMCS beads.
Fig: Van’t Hoff plot of ln Ke vs. 1/T for Cd2+ adsorption onto SMCS beads.
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
3.2E-03 3.2E-03 3.3E-03 3.3E-03 3.4E-03 3.4E-03 3.5E-03
ln
K
e
1/T (K-1)
20 mg/L
30 mg/L
40 mg/L
Thermodynamic study
Results and
Discussion
Summary of the
results

22
Scanning electron microscopic analysis
FTIR analysis
Figure: SEM images of chitosan (CS) beads (a), surfactant modified
chitosan (SMCS) beads (b) cadmium loaded SMCS beads (CdL-SMCS
beads) (c).
Characterization of CS and SMCS beads before and after adsorption of cadmium
Results and
Discussion
Summary of the
results
4000 3500 3000 2500 2000 1500 1000 50
1468
815
890
890
1063
1272
1425
580
809
890
1085
1653
3451
%
Transmittance
Wavenumber
CdL-SMCS beads
1154
1468
1248
1425
667
895
1093
1637
2853
2845
2921
2921
3439
SMCS beads
1154
1376
1428
1652
2862
2917
3439
CS
1212
630
846
980
1082
1253
1468
2845
3461
SDS
2917
(a)
(b)
(c)
(d)
Figure: SEM images of SDS (a), chitosan (CS) beads (b),
surfactant modified chitosan (SMCS) beads (c) cadmium
loaded SMCS beads (CdL-SMCS beads) (d).
SMCS bead as a whole
Surface morphology of
SMCS bead
Surface of SMCS bead
after cadmium adsorption
(a)
(b)
(c)

24
Fig: XRD images of (a) CS powder, (b) SDS powder, (c) SMCS beads, (d)
CdL-SMCS beads.
XRD pattern of adsorbents
At 2Ɵ=18.36o and 22o SDS and at 20o chitosan
showed high intensity peak due to the crystalline
structure
The intensity of the SMCS composite has been
decreased due to the disruption of hydrogen bonds
Decrease in crystallinity results in improvement of
metal adsorption capacity
(a)
(b)
(d)
(c)
2Ɵ (degree)
Results and
Discussion
Summary of the
results

25
Summary of the results
Parameters Optimized value
Dose (g/L) 0.45
pH 6.0-7.0
Adsorption isotherm Langmuir
Kinetics Pseudo second order
Maximum adsorption
capacity (mg/g)
125.00
Equilibrium Time 10 h
Results and
Discussion
Summary of the
results
Material Qmax mg/g Dose (g/L) Isotherm Reference
Chitosan 3.764 40.0 - (Dhanesh and Anjali,
2012)
Composite chitosan
biosorbent (CCB)
108.7 4.0 L (Madala et al., 2013)
Chitosan pyruvic
acid (PA) derivative
98.04 2.0 L (Boamah et al., 2015)
PEO/Chitosan 68.0 1.0 L (Aliabadi et al., 2013)
Chitosan-MAA 1.84 5.0 F (Heidari et al., 2013)
SMCS beads 125.0 0.45 L (Pal and Pal, 2017a)
Conference presentation: Oral
11th Asia Pacific Chitin and Chitosan Symposium & 5th Indian Chitin and Chitosan Society Symposium 28-30th September, 2016,
Kochi, India.

26
Application of SMCS beads for lead ion (Pb2+) removal from
aqueous medium

Fig: Pictorial presentation of formation of SMCS beads and PbL-SMCS beads from CS beads.
(Pal and Pal, 2017b)
Pb2+ removal using SMCS beads
Results and
Discussion
Summary of the
results

Pb2+ conc. (mg/L) 10 20 30 50 100
CS (% R) 94.68 91.68 36.44 22.74 22.15
SMCS (% R) 96.62 92.11 90.64 89.67 70.23
0
20
40
60
80
100
10 20 30 50 100
%
Removal
Pb2+ concentration (mg/L)
CS beads
SMCS beads
Figure: Assessment of CS and SMCS beads for Pb2+ removal efficiency.
Table: Percentage removal of Pb2+ by CS and SMCS beads and their comparison.
Evaluation of the adsorbents (CS and SMCS) for lead removal
Results and
Discussion
Summary of the
results

Kinetic Study
Figure: Effect of contact time on the % removal (a)
and capacity (b) of Pb2+ by SMCS beads. Dose (0.45
g/L).
Optimum time: 8 hrs.
[Pb] mg/L % R
30 ~98
50 ~90
0
20
40
60
80
100
5 10 30 120 240 480 720 1440
%
Removal
Time (min)
30 mg/L
50 mg/L
(a)
0
20
40
60
80
100
120
5 10 30 120 240 480 720 1440
q
t
(mg/g)
Time (min)
30 mg/L 50 mg/L
(b)
Results and
Discussion
Summary of the
results

Table: Parameters of the kinetics study of Pb2+ adsorption onto the SMCS beads.
[Pb]
(mg/L)
qe(expt.)
(mg/g)
Pseudo first order Pseudo second order
qe (mg g−1) k1 (min−1) R2 qe (mg g−1) k2 (g mg−1 min−1) R2
30 64.61 32.52 0.004 0.685 66.67 6.2×10-4 0.998
50 97.76 58.38 0.003 0.933 100.0 4.5×10-4 0.999
Results and
Discussion
Summary of the
results
0
1
2
3
4
5
0 200 400 600 800
ln(q
e
-q
t
)
Tme (min.)
[Pb] 30 mg/L [Pb] 50 mg/L (a)
0
5
10
15
20
25
0 500 1000 1500
t/q
t
(min
g/mg)
Time (min.)
[Pb] 30 mg/L
[Pb] 50 mg/L
(b)
0
50
100
0 250 500 750 1000 1250 1500
q
t
(mg/g)
Time (min)
Experimental qt (50 mg/L)
Theoretical qt (50 mg/L)
Experimental qt (30 mg/L)
Theoretical qt (30 mg/L)
(c)
Figure: Plots of kinetic data for (a) pseudo-first order, (b) pseudo-second
order model, (c) experimental and calculated values of qt (mg/g).
Experimental conditions: Conc. of Pb2+=30 and 50 mg/L, pH=5.0±0.2,
contact time=5-1440 min.
Kinetic models

0
20
40
60
80
100
2 2.5 3 3.5 4 4.5 5 5.5
%
Removal
pH value
50 mg/L
Figure: Role of pH in adsorption of Pb2+ by using SMCS beads.
Experimental conditions: Concentration of Pb2+ = 50 mg/L, dose= 0.45
g/L, temperature= 28oC, pH=2-5.5.
0
10
20
30
40
50
60
70
80
90
100
0.09 0.225 0.36 0.45 0.675 0.9 1.125 1.35
%
Removal
Dose (g/L)
50 mg/L
Figure: Effect of adsorbent dose for adsorption of Pb2+
Experimental conditions: concentration of Pb2+= 50 mg/L, pH= 5.0,
contact time=8 h, temperature= 28oC.
Effect of dosage
Effect of pH
Parameter Optimization
Results and
Discussion
Summary of the
results

32
Figure: Effect of initial concentration of Pb2+ on
adsorption process.
Experimental conditions: Pb2+ conc.= 10-100 mg/L,
dose=0.68 g/L, pH= 5.0±0.2, contact time=8 h,
temperature=28±2ºC.
Results and
Discussion
Summary of the
results
20 30 40
91.96 90.23
81.20
%
Removal
Temperature (ºC)
50 mg/L
Figure: Percentage removal of Pb2+ at different temperature.
Experimental conditions: Conc. of Pb2+=50 mg/L, pH=5.0±0.2,
dose=0.675 g/L, contact time=8 h.
Effect of temperature
Effect of initial concentration

33
Pb2+
concentration
Temperature
(K)
ΔG (kJ/mol) ΔH (kJ/mol) ΔS (J/mol K) R2
293 -5.94
50 mg/L 303 -5.60 -36.91 -104.95 0.894
313 -3.81
Table: Values of thermodynamic parameters for the adsorption of Pb2+ on SMCS beads.
Figure: van’t Hoff plot of ln Ke vs. 1/T (K-1) for Pb2+ adsorption by SMCS beads.
Results and
Discussion
Summary of the
results
Thermodynamic study
0.00
0.50
1.00
1.50
2.00
2.50
3.00
0.00315 0.00320 0.00325 0.00330 0.00335 0.00340 0.00345
ln
K
e
1/T (K-1)

Isotherm Models R2 χ2
=
�
𝐢𝐢=𝟏𝟏
𝒏𝒏
(𝒒𝒒𝐞𝐞 𝒆𝒆𝒆𝒆𝒆𝒆𝒆𝒆 −𝒒𝒒𝐞𝐞 𝒄𝒄𝒄𝒄𝒄𝒄 )𝟐𝟐
𝒒𝒒𝐞𝐞 𝒄𝒄𝒄𝒄𝒄𝒄
Linear Equation
Langmuir qm (mg/g) 100.00 0.984 1.01 Ce/qe = 1/(qm.KL) + (1/qm).Ce
KL (L/mg) 0.084
Freundlich KF(mg/g)(L/mg)1/n 16.44 0.967 1.26 ln qe = ln KF + (1/n) ln Ce
1/n 0.424
Fig: Adsorption isotherm of Pb2+ on SMCS beads by Langmuir
(a) and Freundlich (b) models,
(c) Shows the comparison between the measured and modelled
qe values at different doses .
Experimental conditions: Dose=0.09-1.35 g/L,Pb2+ conc.= 50
mg/L, volume=10 mL, temperature=28±2 ºC, equilibrium
time=8 h.
Table: Values of isotherm constants for Langmuir and Freundlich isotherms and their corresponding R2 values.
Equilibrium isotherm study
Results and
Discussion
Summary of the
results
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0 10 20 30 40 50
Ce/qe
(g/L)
Ce (mg/L)
(a)
0
1
2
3
4
5
1.5 2.0 2.5 3.0 3.5 4.0
Ln
(qe)
Ln (Ce)
(b)
0
20
40
60
80
100
0.09 0.225 0.36 0.45 0.54 0.675 1.125 1.35
q
e
(mg/g)
Dose (g/L)
Experimental (qe)
Langmuir (qe)
Freundlich (qe)
(c)

35
Results and
Discussion
Summary of the
results
Figure: Effect of coexisting anions (a) and cations (b) on Pb2+removal from binary mixtures(Pb2+ conc.=50 mg/L); (c) Removal of other
cations from Pb2+ containing (50 mg/L) binary mixtures.
Exp. Conditions: Conc. of coexisting ions=10, 50, 100 mg/L, volume=10 mL, pH=4.5, temperature=30ºC
Ionic interference study
Anions chosen
NO3
−, SO4
2−, PO4
3 −
Effect of anions :
Nitrate >>sulphate >>phosphate ions
Cations chosen
Cd2+, Zn2+, Ni2+
Negative effect of cations:
Zn2+ >>Cd2+>>Ni2+
Ionic radii: Pb2+>Cd2+>Zn2+>Ni2+
The electronegativity: Zn2<Cd2+<Pb2+<Ni2+
52-60 % Cd2+
42-50 % Zn2+
30-50 % Ni2+
from the binary mixtures
containing 50 mg/L of Pb2+

36
Results and
Discussion
Summary of the
results
Desorption study
0
20
40
60
80
100
98.79 %
0
37.67
15.992 13.69
10.28
8.262
6.702
Desorption
Percentage
(%)
pH value
Desorption with HCl
Desorption with HNO3
Figure: Desorption study performed for recovering Pb2+ from SMCS beads.
Exp. conditions: Pb2+conc.=50 mg/L, pH=3-5.5, contact time=24 h,
agitation speed=100 rpm, temperature=30ºC).
• 98.79 % of Pb2+ (initial concentration=50
mg/L)
• HNO3 and HCl were used for maintain the pH
• pH maintained for the study: 3.0-5.5
Outcome:
• HNO3 showed better results than HCl
• 30-40 % of Pb2+can be recovered at pH 3.0

Figure: SEM images of SMCS (a, b) and PbL-SMCS (c, d)
beads.
(a) (b)
(c) (d)
SEM and FTIR analysis
Results and
Discussion
Summary of the
results
Figure: FTIR spectra of SMCS beads powder(a), and PbL-SMCS
beads powder (b).

Dose (g/L) 0.68
pH 4.5-5.0
Adsorption isotherm Langmuir
Kinetics model followed Pseudo second order
Maximum adsorption
capacity (qmax) (mg/g)
100.00
Inference from the study
Results and
Discussion
Summary of the
results
Material Qmax mg/g Dose
(g/L)
Isotherm Reference
ChB 15.00 6.67 F (Futalan et al., 2012)
Chitosan/PVA hydrogel beads 0.9 25.0 L (Jin and Bai, 2002)
Chitosan from the crab shells 100.0 - F (Bamgbose et al.,
2010)
EGTA-modified chitosan 103.6 0.15 Bi-L (Zhao et al., 2013)
Chitin nanofibers (CNFs) 60.24 1.0 F (Siahkamari et al.,
2017)
Chitosan nanoparticles (CNPs) 94.34 L
SMCS beads 100.0 0.68 L (Pal and Pal, 2017b)
International conference on Energy, Environment and Sustainable Development (ICEESD-2017, 19-20th Oct, 2017), Wembley, London, UK.

39
Methylene blue removal using the waste beads generated after
cadmium adsorption

Figure: Schematic of the formation of CS beads and its modification with SDS for removal of Cd2+ to form CdL-
SMCS beads followed by the adsorption of MB.
4
CS beads
SMCS beads
CdL-SMCS beads
MBL-SMCS beads
CS powder
Step 1
Step 2
Step 3
Step 4
Methylene Blue Removal: After Adsorption of Cadmium onto SMCS Beads
Results and
Discussion
Summary of the
results
MB removal using CdL-SMCS beads

0
100
200
300
400
10 20 50 100 250
q
t
(mg/g)
MB concentration (mg/L)
CS beads
CdL-SMCS beads
Figure: Evaluation of the CS and Cd2+ loaded SMCS beads (Cd2+
loading = 125 mg/g) for removal of MB.
Experimental conditions: [MB]: 10-250 mg/L, adsorbent dose: 0.45g/L,
time: 72 h, agitation speed: 100 rpm, temperature: 30oC.
Evaluation of the CS and CdL-SMCS beads for
removal of MB
5
Type of
adsorbent
[MB] (mg/L) *qt (mg/g)
CS beads 250 64.35
CdL-SMCS
beads
250 366.46
*qt = mg of adsorbate (MB) adsorbed on the adsorbent (CdL-SMCS) in a given time
Results and
Discussion
Summary of the
results
0
10
20
30
40
50
60
70
80
90
100
0
50
100
150
200
250
10 20 30 50 100
%
Removal
of
MB
q
t
(mg/g)
Cd2+ concentration used for SMCS beads loading
(mg/L)
qt (mg/g) for MB removal
qt (mg/g) for Cd2+ removal
% Removal (MB)
Figure: Effect of Cd2+ loading on removal of MB by CdL-
SMCS beads.
Experimental conditions: [MB]: 50 mg/L, dose: 0.45g/L, time:
72 h, agitation: 100 rpm, temperature: 30oC.
Selection of beads after Cd2+
loading

Effect of contact time and dosage on adsorption of MB on CdL-SMCS beads
88.75
92.06
92.75
0
10
20
30
40
50
60
70
80
90
100
0 0.083 0.5 1 2 4 12 24 48 72 96
%
Removal
of
MB
Time (h)
Figure: Time dependency on removal of MB using CdL-SMCS
beads.
Exp. conditions: [MB]: 50 mg/L, dose: 0.45g/L, agitation: 100
rpm, temperature: 30oC.
7
Time (h) % R of MB
48 88.75
72 92.06
96 92.75
Results and
Discussion
Summary of the
results
0
50
100
150
200
250
300
350
400
450
500
50
60
70
80
90
100
0.09 0.225 0.45 0.675 0.9 1.35
q
t
(mg/g)
%
Removal
of
MB
Dose (g/L)
% Removal
Capacity (mg/g)
Dose (g/L) % R of MB
0.45 95.63
0.68 96.15
Figure: Effect of adsorbent dosage on removal of MB by CdL-
SMCS beads.
Exp. conditions: [MB]: 50 mg/L, time: 72 h, agitation speed:
100 rpm, temperature: 30oC.

Figure: Effect of MB concentration on its removal by CdL-SMCS beads. The photograph showing (a) SMCS beads, (b)
CdL-SMCS beads, (c) 10 mg/L MB loaded beads (d) 50 mg/L MB loaded beads.
Exp. conditions: [MB]: 10-250 mg/L, dose: 0.45 g/L, time: 72 h, agitation speed: 100 rpm.
Effect of MB concentration
9
Results and
Discussion
Summary of the
results
%
Removal
of
methylene
blue
Methylene blue (MB) concentration ((mg/L)

Model Pseudo first order Pseudo second order
Equation of linear fit
line
Ln (qe-qt) =-0.0009x + 3.6812 t/qt = 0.0097x + 0.4675
R2 0.878 0.999
qe (mg/g) 39.69 103.09
Constant (k) kS1 =9.0×10-4 (min−1) kS2=2.0×10-4 (g mg−1 min−1)
Kinetic study for adsorption of MB on to CdL-SMCS beads
Figure: Kinetics on MB removal by CdL-SMCS beads. (a) The fitting of pseudo first order and pseudo second order model, and (b)
plot of qt vs. t for experimental data and calculated values of qe (based on the pseudo-second order model).
Exp. conditions: [MB]: 50 mg/L, dose: 0.45g/L, time: 72 h, agitation: 100 rpm, temperature: 30oC.
Table: Pseudo first order and pseudo second order rate constants of MB adsorption onto the CdL-SMCS beads.
10
-1
0
1
2
3
4
5
0
10
20
30
40
50
60
0 2000 4000 6000
Ln
(qe-qt)
t/q
t
Time (min)
Pseudo second order curve fitting
Pseudo first order curve fitting
(a)
0
20
40
60
80
100
120
0 1000 2000 3000 4000 5000 6000
q
t
(mg/g)
Time (min)
qt calculated
qt experimental
(b)
Results and
Discussion
Summary of the
results

0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0 50 100 150
C
e
/q
e
(g/L)
Ce (mg/L)
(a)
0
1
2
3
4
5
6
7
-1 0 1 2 3 4 5 6
ln
(qe)
ln (Ce)
(b)
Figure: Langmuir (a) and Freundlich (b) adsorption isotherm model for removal of MB using CdL-SMCS beads. [MB]: 10-250
mg/L, dose: 0.45g/L, time: 72 h, agitation: 100 rpm, temperature: 30oC.
Equilibrium adsorption isotherm study on MB removal by CdL-SMCS beads
11
Model Parameters Values
Langmuir isotherm model
Equation Ce/qe = 0.002Ce + 0.062
qmax (mg/g) (Maximum
adsorption capacity)
500.0
KL 0.0323
R2 0.922
Freundlich isotherm model
Equation lnqe = 0.516 lnCe + 3.342
KF [(mg/g)(L/mg)1/n]
(constant related to
adsorption capacity)
28.76
1/n (adsorption intensity) 0.516
R2 0.985
Table: Adsorption isotherm model equations, values of isotherm constants and their corresponding R2 values.
Results and
Discussion
Summary of the
results

Summary of the result
13
Parameters Methylene blue
Dose (g/L) 0.45
pH 6.0-7.0
Adsorption isotherm model Freundlich
Kinetic model Pseudo second order
Maximum adsorption capacity
(mg/g)
500.0
Results and
Discussion
Summary of the
results
Adsorbent qmax (mg/g) Reference
Chitosan (CB) 99.01 (Chatterjee et al., 2011)
Surfactant Modified (CB) 226.24 (Lin et al., 2017)
Chitosan hydrogel beads (CSB) 129.44 (Chatterjee et al., 2011)
Raw wheat straw 55.0 (Azadeh et al., 2015)
Surfactant modified wheat straw 126.60
Hydrotalcite-iron oxide magnetic
organocomposite (HT-DS/Fe)
110.05 (Miranda et al., 2014)
CdL-SMCS beads 500.0 Pal and Pal, 2018
National Conference on Sustainable Advanced Technologies for Environmental Management (SATEM-2017) June 28-30th, 2017,
Shibpur, India.

47
Crystal violet and tartrazine removal using the waste beads
generated after lead adsorption

Flow chart for CV and TZ removal by PbL-SMCS beads
48
1
Results and
Discussion
Summary of the
results
Figure: Pictorial presentation of formation of SMCS beads and PbL-SMCS
beads from CS beads (Pal and Pal, 2019a).

Figure: Assessment of CS, SMCS and PbL-SMCS beads for dyes removal.
Selection of the adsorbent and dye for experiment
Results and
Discussion
Inference from
the study
49
CS
SMCS
PbL-SMCS
MB CV MO TZ
CS 7.33 6.78 27.19 66.16
SMCS 43.59 96.27 13.90 71.53
PbL-SMCS 57.93 92.34 46.66 87.35
7.33
6.78
27.19
66.16
43.59
90.27
13.90
71.53
57.93
92.34
46.66
87.35
%
Removal
Type of dye
CS
SMCS
PbL-SMCS

Optimum time: 2 h
50
Effect of contact time on adsorption of CV and TZ by PbL-SMCS beads
Figure: Time dependency on removal of CV and TZ using PbL-SMCS beads.
Experimental conditions: [dye]: 20 mg/L, dose: 0.45g/L, agitation: 100 rpm,
temperature: 30oC.
Time
(min)
% R of dye
CV TZ
120 85.44 85.05
Results and
Discussion
Summary of the
results
0
20
40
60
0
20
40
60
80
100
5 10 30 60 90 120 240 360 480 720 1440 2160 2880 4320
Adsorbate/gm
of
adsorbent
(mg/g)
%
Removal
of
CV
and
TZ
Time (min)
CV (% R) TZ (% R) CV (capacity mg/g) TZ (capacity mg/g)

Table: Pseudo second order rate constants of CV and TZ adsorption onto the PbL-SMCS beads.
Figure: Pseudo-second order model for CV and TZ adsorption on PbL-SMCS beads (a) and experimental and theoretical curve plot
on the basis of pseudo-second order model equation (c). Conc. of CV and TZ: 20 mg/L, pH: 6.0 for CV and 3.0 for TZ, temperature:
30 oC.
Results and
Discussion
Inference from
the study
51
Kinetic models
0
20
40
60
80
100
120
0 1000 2000 3000 4000
t/q
t
Time (min.)
CV TZ
(a)
Dye
Equation of linear fit
line
R2 qe(Exp)
Pseudo-second order model
parameters
Values for constants
CV y = 0.0247x + 2.3721 0.993 39.25
KS2 (g/mg/min) 2.57×10-4
qe(theo.) mg/g 40.48
TZ y = 0.0212x + 0.6379 0.999 46.91
KS2 (g/mg/min) 7.04×10-4
qe(theo.) mg/g 47.16
0
5
10
15
20
25
30
35
0 1000 2000 3000 4000
q
t
(mg/g)
Time (min)
Theoretical qt (mg/g) (CV)
Expermimental (CV)
Theoretical qe (mg/g) (TZ)
Experimental qt (mg/g) (TZ)
(b)

52
0
20
40
60
80
100
3 4 5 6 7 8 10
%
Removal
pH of the dye solution (CV and TZ both)
CV TZ
Figure: Effect of pH on the % removal CV and TZ by PbL-SMCS beads.
Exp. conditions: [dyes]: 20 mg/L, time: 2 h, agitation speed: 100 rpm, temperature: 30oC.
Effect of pH on adsorption of CV and TZ
Dye Optimum pH % R of dye
CV 6.0 91.16
TZ 3.0 80.61
Results and
Discussion
Summary of the
results

54
0
10
20
30
40
50
60
70
80
90
100
0.18 0.27 0.36 0.45 0.72 0.9 1.08 1.35
%
Removal
Dose (g/L)
CV (%R) TZ (%R)
Dye Optimum dose (g/L) % R of dye
CV 0.36 88.88
TZ 0.72 86.17
Figure: Effect of adsorbent dosage on removal of CV and TZ by
PbL-SMCS beads.
Exp. conditions: [dyes]: 20 mg/L, time: 2 h, agitation speed: 100
rpm, temperature: 30oC.
Figure: The photograph showing the colour of dye
before and after adsorption (a) CV, (b) TZ. (dose study)
Effect of adsorbent dose on adsorption of CV and TZ
Results and
Discussion
Summary of the
results

55
Effect of dye concentration on % removal efficiency of PbL-SMCS beads
Figure: Effect of dyes concentration on removal by PbL-SMCS
beads.
Exp. conditions: [dyes]: 5-100 mg/L, dose: 0.36 g/L for CV and 0.72
g/L for TZ, time: 2 h, agitation speed: 100 rpm.
(a)
(b)
(d)
(c)
Results and
Discussion
Summary of the
results
Figure: The photograph showing
(a) color of the solution of different CV concentrations after
adsorption
(b) CV loaded PbL-SMCS beads
(c) color of the solution of different TZ concentrations after
adsorption
(d) TZ loaded PbL-SMCS beads.
0
20
40
60
80
100
0
20
40
60
80
100
5 10 20 30 50 100 Adsorbate
per
gm
of
adsorbent
(mg/g)
%
Removal
of
dyes
Concentration of CV and TZ (mg/L)
% R (CV) % R (TZ)
Capacity (mg/g) (CV) Capacity (mg/g) (TZ)
(a)
The standard deviation (SD) and standard error (std. error) calculation
shows that, the SD varies in the range from 1.13-5.12 for CV and 0.97-
7.3 for TZ.

Figure: Langmuir (a), Freundlich (b), Temkin (c), and
Dubinin-Radushkvich (DR) (d) adsorption isotherm on
removal of CV and TZ using PbL-SMCS beads.
Exp conditions: dye conc:10-100 mg/L, dose: dose: 0.36 g/L
for CV and 0.72 g/L for TZ, time: 2 h, pH 6.0 for CV and 3.0
for TZ
Isotherm study
Results and
Discussion
Inference from
the study
56
Adsorption isotherm models Parameters CV TZ
Langmuir qm (mg/g) 97.097 30.030
KL (L/mg) 0.2219 0.173
R2 0.989 0.907
Freundlich KF (mg/g)(L/mg)1/n (constant related to adsorption
capacity)
18.31 6.659
1/n (adsorption intensity) 0.540 0.401
R2 0.952 0.9696
Temkin At (L/mg) 2.645 2.949
b (J/mol) 126.82 464.19
R2 0.969 0.893
D-R BD 3.0×10-7 3.0×10-7
qm (mg/g) 64.321 23.25
E (mean free energy)(kJ/mol) 1.29 1.29
R2 0.863 0.547

Table: Values of thermodynamic parameters for the adsorption of Pb2+ on SMCS beads.
Thermodynamic parameters
Results and
Discussion
Inference from
the study
57
• Spontaneous and favorable
• Endothermic
• Increased randomness with
increasing the temperature
CV
Temperature
(K)
Initial metal ion
concentration (mg/L)
ΔG
(kJ/mol)
ΔH
(kJ/mol)
ΔS
(J/mol K)
303 20 -4.97 27.82 108.84
313 20 -6.65
323 20 -7.12
TZ
303 20 -0.86 16.47 56.95
313 20 -1.21
323 20 -2.01
0
5
10
15
20
Co (mg/L) 303 313 323
Remaining
Concentration
of
CV
and
TZ
(mg/L)
Temperature (K)
CV
TZ
(a)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.1E-033.1E-033.2E-033.2E-033.3E-033.3E-033.4E-03
ln
Ke
1/T (K-1)
CV
TZ
(b)
Figure: Effect of temperature on CV and TZ removal (a), and van’t Hoff plot Ke vs. 1/T (K−1) for CV and TZ adsorption by
PbL-SMCS bead (b). ([dye]: 20 mg/L, dose: 0.72 g/L, agitation: 120 rpm, time: 2 h, pH 6.0 for CV and 3.0 for TZ).

Figure: SEM images of PbL-SMCS (a, d), CV- PbL-SMCS (b, e),
and TZ- PbL-SMCS beads (c, h).
SEM analysis
58
Results and
Discussion
Inference from
the study
FTIR analysis
Figure: FTIR spectra of SMCS (a), PbL-SMCS (b), CV-Pb-
SMCS (c), and TZ-Pb-SMCS (d) beads.

59
Parameters CV TZ
Dose (g/L) 0.36 0.72
pH 6.0 3.0
Adsorption isotherm
model
Langmuir Freundlich
Kinetics model Pseudo second
order
Pseudo second
order
Maximum
adsorption capacity
(mg/g)
97.09 30.03
Equilibrium Time 2 h 2 h
Results and
Discussion
Summary of the
results
Adsorbent used qm (mg/g) Reference
CV
Eco-friendly activated carbon
from sargassm wightii sea weeds
21.05 (Jayganesh et al., 2017)
CMRS (Citric acid modified rice straw) 90.82 (Chowdhury, 2013)
Cucumis sativa activated carbon 34.24 (Smitha et al., 2012)
Coniferous pinus bark powder (CPBP) 32.78 (Ahmad, 2009)
Modified bambusa tulda 20.84 (Laskar and Kumar 2018)
PbL-SMCS beads 97.09 (Pal and Pal, 2019a)
TZ
Chitosan 350 (Dotto et al., 2012)
Chitin 4.04
Commercial activated carbon 4.84 Jibril et al., 2019)
Saw dust 4.71 (Banerjee and
Chattopadhyaya, 2017)
Activated carbon biosorbents from Lantana
camara weed
90.90 (Gautam et al., 2015)
PbL-SMCS beads 30.03 (Pal and Pal, 2019a)
Paper considered for revision in Journal of Water Process Engineering
Submission ref: JWPE_2019_161
Submission title: Dye removal using waste beads: Efficient utilization of surface-modified chitosan
beads generated after lead adsorption process
Authors: Preeti Pal, Anjali Pal
Journal: Journal of Water Process Engineering
Conference presentation: Poster presentation
8th International Colloids Conference 2018, Shanghai, China, June 10 – 13th, 2018.

60
Applicability of SMCS beads for Cd2+ removal from mixed
wastewater

61
Pictorial presentation of formation of SMCS beads and its application for Cd2+ removal from mixed
wastewater
Stepwise flow diagram of the process
Results and
Discussion
Summary of the
results

62
Adsorption study in Real Wastewater (RWW)
Parameters RWW Instrument used
pH 7.25 5.8 Eutech
instruments pH 510
(India)
Conductivity 1415 Conductivity meter
Salinity 0.71
Multi parameter kit
Total dissolved
solids (TDS)
708
ORP 78.2
Cations (mg/L)
Na 650.66 Ion chromatography
DIONEX ICS-2100,
ThermoScientific
(column:CS-11)
K 13.04
Ca 62.11
NH4 20.83
Mg 29.8
Cd 12.0±2 atomic absorption
spectrophotometer
(AAS)
(ThermoScientific,
iC3300)
Pb 6.7
Mn -
Cu 7.15
Fe -
Ni -
0
10
20
30
40
50
0
10
20
30
40
50
60
70
80
90
0
5
10
15
20
30
60
90
120
240
360
480
720
1200
1440
2160
2880
Capacity
(mg/g)
%
Removal Time (min)
% R Cd2+
Capacity (mg/g)
Effect of contact time on the % removal of Cd2+ by SMCS beads
Exp. conditions: dose= 0.72 g/L,
agitation=100 rpm, temperature=30oC.
Characteristics of RWW before treatment
Results and
Discussion
Summary of the
results

63
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
3.2E-03 3.2E-03 3.3E-03 3.3E-03 3.4E-03 3.4E-03 3.5E-03
ln
K
e
1/T (K-1)
Temperature (K) Δ G
(kJ/mol)
ΔH
(kJ/mol)
Δ S
(J/K/mol)
R2
293 -1.75
42.14 108.84 0.990
303 -3.01
313 -4.75
0
20
40
60
80
100
0 0.18 0.36 0.54 0.72 0.9 1.08 1.44 1.8
%
Removal
Dose (g/L)
Effect of adsorbent dosage on removal of
Cd2+ from RWW by SMCS beads
Effect of temperature and van’t Hoff plot Ke vs. 1/T (K−1)
for Cd2+ removal onto SMCS beads.
• Optimum dose: 0.9 g/L
• Spontaneous and favorable
• Endothermic
• Increased movement of molecules
with increasing the temperature
Results and
Discussion
Summary of the
results
Table: Values of thermodynamic parameters for Cd2+ removal using
SMCS beads in RWW.

64
y = -0.0023x + 1.7877
R² = 0.9197
-4
-3
-2
-1
0
1
2
3
0 500 1000 1500 2000 2500
ln
(q
e
-q
t
)
Time (min)
y = 0.0933x + 12.255
R² = 0.9891
0
50
100
150
200
250
300
0 500 1000 1500 2000 2500 3000
t/q
t
Time (min)
0
2
4
6
8
10
12
14
0 5 10 15 20 25 30 35 40
q
t
(mg/g)
time0.5
0
2
4
6
8
10
12
0 250 500 750 1000 1250 1500
q
t
(mg/g)
Time (min)
Throretical qe (mg/g)
Experimental qe (mg/g)
Pseudo-first and pseudo-second order model curve fitting for Cd2+
adsorption onto SMCS beads.
Plot of qt vs. t for
experimental data and
theoretical data based on the
pseudo-second order model.
Intra-particle diffusion model curve
fitting for Cd2+ adsorption
Kinetic model Kinetic parameters
Pseudo first
order
ks1 (min−1) 2.3×10-3
qe (mg g−1) 5.98
R2 0.919
Chi-square 315.19
SAE* 41.66
Pseudo second
order
ks2 (g mg−1 min−1) 6.2×10-4
qe(theo) (mg g−1) 10.72
qe(expt.) (mg g−1) 9.98
R2 0.989
Chi-square 6.741
SAE* 10.91
Intra-particle
diffusion
kid 0.164
Ci 3.46
R2 0.617
Exp. conditions: Time 5 min to 48 h, dose=
0.72 g/L, agitation=100 rpm,
temperature=30oC.
Results and
Discussion
Summary of the
results

65
Isotherm
models
Constants and their
values
R2
Langmuir qm (mg/g) 18.73 0.978
KL (L/mg) 2.59
Freundlich Kf 11.44 0.982
1/n 0.252
Temkin At (L/mg) 102.78 0.946
bt (mg/g) 948.18
B 2.66
D-R BD 2×10-8 0.943
qD (mg/g) 13.26
E (kJ/mol) 5.0
Langmuir (a), Freundlich (b), Temkin (c), and Dubinin-Radushkvich (d) adsorption isotherm on
removal of Cd2+ using SMCS beads
0
5
10
15
20
-4.0 -2.0 0.0 2.0 4.0
q
e
(mg/g)
ln Ce
0
1
1
2
2
3
3
4
0.0E+0 5.0E+7 1.0E+8
ln
Ce
(RT ln (1+ (1/Ce))2
(c)
0.0
0.1
0.2
0.3
0.4
0.0 2.0 4.0 6.0 8.0
C
e
/q
e
(g/L)
Ce (mg/L)
0.0
1.0
2.0
3.0
4.0
-4.0 -2.0 0.0 2.0 4.0
ln
(q
e
)
ln (Ce)
(b)
(d)
Experimental conditions: Time 24 h, dose=
0.72 g/L, agitation=100 rpm,
temperature=30oC.
Results and
Discussion
Summary of the
results
0
5
10
15
20
0.18 0.36 0.54 0.72 0.9 1.08 1.44 1.8
Adsorption
capacity
(mg/g)
Dose (g/L)
Experimental capacity (mg/g)
Langmuir qe(calc)
Freundlich qe(calc.)
Temkin qe(calc.)
D-R qe(calc.)
(e)
Comparison between the experimental
and calculated qe (mg/g) values for Cd2+
adsorption onto SMCS beads from
RWW

66
(RWW)
Optimized value
(CCDW)
Dose (g/L) 0.9 0.45
pH 7.0 6.0-7.0
Adsorption isotherm model Freundlich Langmuir
Kinetics model Pseudo second order Pseudo second order
Maximum adsorption capacity
(mg/g)
18.72 125.00
Equilibrium Time 24 h 10 h
Summary of the results obtained in mixed WW and its comparison with the
results obtained in cadmium containing distilled water (CCDW)
Results and
Discussion
Summary of the
results
Conference presentation: Oral presentation
14th International Chitin and Chitosan Conference (14th ICCC) & 12th Asia‐Pacific Chitin and Chitosan Symposium (12th APCCS),
Kansai University, Osaka, Japan, 27th to 30th August, 2018

67
Applicability of SMCS beads for Cd2+ removal in continuous
column mode

68
Application of SMCS beads in continuous column mode
Results and
Discussion
Summary of the
results
Figure: Schematic diagram of continuous column
for cadmium ion removal.
0
0.2
0.4
0.6
0.8
1
5 10 15 20 25 30 35 40 45 50 60 90 120 180 240
C/C
0
Time (min)
SMCS beads CS beads
Comparison of CS and SMCS in continuous
column mode
Figure: Curves for Cd2+ removal by CS and SMCS beads.
Column height: 30 cm
Column diameter: 1.5 cm
Column material: glass column
Bed
Height Influent
Glass column
Glass wool
Glass wool
SMCS beads
Effluent
Water flow
Flow controlling knob

69
Heavy metal Bed depth (cm) Ttotal (min) qtotal (mg) qeq (mg/g) Mtotal (mg) Removal
efficiency
Cd2+
4.5 90 0.46 1.022 1.24 36.98
5.5 120 0.48 0.722 1.66 29.26
9.0 180 0.58 0.64 2.48 23.213
Table: The effect of bed depths on the qtotal, qeq, Ttotal, and percentage removal efficiency of Cd2+ adsorption on SMCS beads.
Results and
Discussion
Summary of the
results
Effect of variation of dose/bed depth
Effect of various parameters on the removal efficiency of SMCS beads in continuous column
Figure: Breakthrough curves for Cd2+ removal by SMCS beads column for
different bed depths.
Conc. Flow rate
(mL/min)
Bed depth
(cm)
No. of
beads
Weight of SMCS
gel beads
10 mg/L 1.0 4.5 100
0.45
5.5 150
0.68
9.0 200
0.9
Experimental
conditions
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
5 10 15 20 25 30 35 40 45 50 60 90 120 180 240
C/C
0
Time (min)
4.5 cm
5.5 cm
9 cm
95 % saturation line
*Maximum column capacity: qtotal (mg), Total amount of metal ions sent to column: Mtotal, Column exhaust time: Ttotal, Adsorption capacity at exhaust point: qeq (mg/g)

70
Heavy
Metal
Flow rate
(mL/min)
qtotal (mg) qeq (mg/g) ttotal (min) Mtotal (mg) Removal
efficiency
Cd2+
1.0 0.53 1.18 240 3.31 16.49
1.5 0.69 1.53 180 3.72 18.87
2.0 0.77 1.72 60 4.9 15.93
Table: The effect of flow rate on the qtotal, qeq, ttotal, and percentage removal efficiency of Cd2+ adsorption on SMCS beads.
Figure: Breakthrough curves for Cd2+ removal by SMCS in continuous column
for different flow rates (1.0, 1.5, 2.0 mg/L).
Results and
Discussion
Summary of the
results
Effect of variation of flow rate
Conc. Bed depth (cm) Flow rate (mL/min)
10 mg/L 4.5 cm or
100
SMCS beads or
0.45 g dry weight
of the beads
1.0
1.5
2.0
Experimental
conditions
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 5 10 15 20 25 30 35 40 45 50 60 90 120 180 240
C/C
0
Time (min)
1.0 mL/min
1.5 mL/min
2.0 mL/min

71
Table: The effect of flow rate on the qtotal, qeq, ttotal, and percentage removal efficiency of Cd2+ adsorption on SMCS beads.
Results and
Discussion
Summary of the
results
Experimental
conditions
Effect of variation of cadmium concentration
Figure: Breakthrough curves for Cd2+ removal by SMCS in continuous column at
different Cd2+ concentration ([C0]=5, 10, and 20 mg/L).
Flow rate
(mL/min)
Bed depth (cm) Conc. (mg/L)
1.0
4.5 cm or
100
SMCS beads or
0.45 g dry weight of
the beads
5
10
20
Heavy metal C0 (mg/L) qtotal (mg) qeq (mg/g) ttotal (min) Mtotal (mg)
Removal
efficiency (%)
Cd2+
5 0.091 0.20 240 1.40 36.48
10 0.38 0.84 120 1.42 26.56
20 0.49 1.09 60 0.73 45.89
0
0.2
0.4
0.6
0.8
1
5 10 15 20 25 30 35 40 45 50 60 90 120 180 240 300
C/C
0
Time (min)
5 mg/L
10 mg/L
20 mg/L

72
• Volume of the effluent treated:
Veff = Q × t
• Mass of pollutants adsorbed or the column capacity at a given flowrate and inlet concentration can be calculated by the
given formula:
qtotal =
Q × A
1000
where A = �
t0
ttotal
(C0 − Ct)dt
Where, C0 and Ct are the influent and effluent metal ions concentration (mg/L), A is the area under the breakthrough curve (mg min/L)
and ttotal is the total time of flow up to the exhaustion (min), Q (mL/min) is the flow rate at which Cd2+ solution is flowing through the
column.
• Total mass of Cd2+ pass through the column:
Mtotal =
C0 × Q × ttotal
1000
• Capacity at equilibrium can be calculated by dividing total mass of the Cd2+ passed through the column (mg) by mass of
adsorbent (m) used in the column (mg).
qeq =
Mtotal
m
• The removal efficiency :
Removal efficiency =
qtotal
Mtotal
× 100
Formulae used for the calculation of column adsorption parameters

73
Results and
Discussion
Summary of the
results
Modelling of breakthrough curves
-5
-3
-1
1
3
5
0 10 20 30 40 50 60 70
ln
((C
0
/C
t
)-1)
Time (min)
4.0 cm- 1.0 mL/min
5.5 cm-1.0 ml/min
9.0 cm-1.0 mL/min
4.0 cm-1.5 mg/L
4.0 cm-2.0 mL/min
Bed depth
(cm)
Flow rate (Q)
(mL/min)
C0
(mg/L)
kYN τ Y-N model
R2
KTH q0 (mg/g) Thomas
model R2
4 1.0 10 0.124 26.98 0.963 8.5×10-3 0.81 0.979
5.5 1.0 10 0.098 28.30 0.921 7.2×10-4 4.87 0.948
9.0 1.0 10 0.086 40.60 0.91 6.1×10-3 0.49 0.947
4.0 1.5 10 0.13 32.75 0.97 9.7×10-3 1.01 0.972
4.0 2.0 10 0.12 33.48 0.95 8.8×10-3 1.03 0.956
(b) Thomas plot
-6
-4
-2
0
2
4
6
0 10 20 30 40 50 60 70
ln
(C
t
/(C
0
-C
t
))
Time (min)
4.5 cm- 1.0 mL/min
5.5 cm-1.0 mL/min
9.0 cm-1.0 mL/min
4.0 cm-1.5 mL/min
4.0 cm- 2.0 mL/min
Figure: Yoon-Nelson and Thomas kinetic plot for adsorption of Cd2+ on SMCS beads at different bed depth and flow rates.
(a) Yoon-Nelson plot
y = 2.0149x + 2.2388
R² = 0.9067
y = 19.254x + 8.0597
R² = 0.9856
0
50
100
150
200
3.5 5 6.5 8 9.5
Time
(min)
Bed depth (cm)
Breakthrough time
Exhaust time
Metal h (cm) Vt (mL) Service time Overall zorption
zone (min)
Mass
transfer
zone
N0
(mg/L)
V
(cm/min)
Removal
efficiency
BT (min) ET (min)
Cd2+ 4.5 90 10 90 80
3.56 1.17 0.045 36.97
5.5 120 15 120 115
4.81 0.89 0.034 29.22
9.0 180 20 180 160
8.0 0.57 0.022 23.21
Figure: BDST model plot for different breakthrough points.
BDST plot

74
Results and
Discussion
Summary of the
results
• SMCS were successfully prepared and used for the removal of various contaminants in our study.
• The removal of Cd2+ occurred within the equilibrium time of 10 h with the optimum dose of 0.45 g/L.
The adsorption followed Langmuir isotherm and Langmuir adsorption capacity was found to be 125
mg/g .
• The removal of Pb2+ occurred within the equilibrium time of 8 h with the optimum dose of 0.68 g/L.
The adsorption followed Langmuir isotherm and Langmuir adsorption capacity was found to be 100.0
mg/g .
• On the basis of interference study for Pb+ removal, we can conclude that the adsorption onto SMCS is
competitive rather than selective.
• Cd2+ loaded SMCS beads were efficiently removed MB from aqueous solution with the dose of 0.45
g/L with the adsorption capacity of 500 mg/g.
• Pb2+ loaded-SMCS beads successfully removed CV and TZ from aqueous solution with the adsorption
capacity of 97.09 and 30.03 mg/g.
• Experiments on Cd2+ containing ([C0]=12±2.0 mg/L) industrial wastewater by SMCS resulted in the
removal efficiency of ~80% within 24 h with the adsorption capacity of 18.20 mg/g.
• Column study have resulted in the maximum removal efficiency of near about 36 % with the 5.0 mg/L
Cd2+ concentration, when the flow rate was 1.0 mL/min.
Conclusions

75
1. Preeti Pal, Anjali Pal, 2017, Surfactant-modified chitosan beads for cadmium ion adsorption, International Journal of Biological Macromolecules, vol. 104, Part
B, 1548-1555.
2. Preeti Pal, Anjali Pal, 2017, Enhanced Pb2+ removal by anionic surfactant bilayer anchored on chitosan bead surface, Journal of Molecular Liquids, vol. 248,
713-724.
3. Preeti Pal, Anjali Pal, 2017, Modification of chitosan for cadmium removal: A short review, Journal of polymer Materials, vol. 34, 331-341.
4. Preeti Pal, Anjali Pal, 2018, Lead cleanup from environment using altered form of chitosan: A review, Recent Patents on Engineering, vol. 12, 175-185.
5. Preeti Pal, Anjali Pal, 2018, Methylene Blue Removal: An approach towards sludge management after adsorption of cadmium onto surfactant-modified chitosan
beads, Journal of Indian Chemical Society, vol. 95, 357-364.
6. Preeti Pal, Anjali Pal, 2018, Role of surfactants in enhancing the biosorption capacity of chitosan, Chapter 9 in book: Chitosan-based adsorbents for wastewater
treatment, Materials Research Forum, 34, 218-229.
7. Preeti Pal, Anjali Pal, 2019, Treatment of real wastewater: Kinetic and thermodynamic aspects of cadmium adsorption onto surfactant-modified chitosan beads,
International Journal of Biological Macromolecules, vol. 131, 1092-1100.
8. Preeti Pal, Asmaa Benettayab, Anjali Pal, 2019, Environmentally safe biosorbents for crystal violet removal from wastewater. Nova Science publishers, Inc.,
NY, USA (accepted, in press).
9. Preeti Pal, Anjali Pal, Dye removal using waste beads: Efficient utilization of lead-loaded surfactant-modified chitosan beads generated after lead adsorption
process (considered for revision in Journal of Water Process Engineering).
10. Pau Loke Show, Preeti Pal, Hui Yi Leong, Joon Ching Jaun, Tau Chuan Ling, 2019, A review on the advanced leachate treatment technologies and their
performance comparison: an opportunity to keep the environment safe, Environ Monit Assess., 2019, 191-227.
11. Preeti Pal, Anjali Pal, Applications of chitosan in environmental biotechnology. (under review).
12. Preeti Pal, Anjali Pal, Utilization of Bengal gram husk as an efficient and cost effective adsorbent for heavy metal and dye removal in single and binary system
(under review).
13. Pau Loke Show, Preeti Pal, Joon Ching Jaun, Tau Chuan Ling, 2019, Green treatment for landfill leachate via physicochemical and adsorption process: A
Review (under review)
Contribution by the scholar during PhD
Results and
Discussion
Summary of the
results
Conclusions
Contribution by
scholar
References

76
• 14th International Chitin and Chitosan Conference (14th ICCC) & 12th Asia‐Pacific Chitin and Chitosan Symposium (12th APCCS), Kansai University, Osaka, Japan,
27th to 30th August, 2018
Topic of the paper presented (oral): Treatment of real wastewater: Kinetic and thermodynamic aspects of cadmium adsorption onto surfactant-modified
chitosan beads
• 8th International Colloids Conference 2018, Shanghai, China, June 10 - 13, 2018
Topic of the paper presented (poster): Dye removal using waste beads: Efficient utilization of lead-loaded surfactant-modified chitosan beads generated
after lead adsorption process.
• International Conference on Emerging Trends in Biotechnology for Waste Conversion (ETBWC) 2017 and XIV Annual Convention of “The Biotech Research Society
(BRSI)”, India, Organized by CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur Maharashtra (October 8-10,2017).
Topic of the poster presented: Utilization of Bengal gram husk as an efficient and cost effective adsorbent for heavy metal and dye removal in single and
binary system
• International conference on Energy, Environment and Sustainable Development (ICEESD-2017, 19-20 Oct, 2017), Wembley, London, UK.
Topic of the paper presented: Surfactant-Modified Chitosan Beads: An Efficient and Cost Effective Material for Adsorptive Removal of Lead from
Aqueous Solutions
• National Conference on Sustainable Advanced Technologies for Environmental Management (SATEM-2017) June 28-30, 2017
Topic of the paper presented: Methylene Blue Removal: An Approach towards Sludge Management after Adsorption of Cadmium onto Surfactant
Modified Chitosan Beads.
• 11th Asia Pacific Chitin and Chitosan Symposium & 5th Indian Chitin and Chitosan Society Symposium 28-30th September, 2016
Topic of the paper presented: Surfactant-modified chitosan beads for cadmium adsorption.
Papers presented in conferences

• World Health Organization., 2008. Guidelines for drinking-water quality. World Health Organization, Geneva, Vol I, Third edition.
• U. S. Agency for Toxic Substances and Disease Registry. Syracuse Research Corporation. Toxicological profile for lead. Agency for Toxic Substances and Disease
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aqueous solution. Chem. Eng. Process Technol. 6, 1–9.
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anionic surfactant. Bioresour. Technol. 100, 3862–3868. doi:10.1016/j.biortech.2009.03.023
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system. Sustain. Environ. Res 22, 345–355.
• Heidari, A., Younesi, H., Mehraban, Z., Heikkinen, H., 2013. Selective adsorption of Pb(II), Cd(II), and Ni(II) ions from aqueous solution using chitosan-MAA
nanoparticles. Int. J. Bol. Macromol. 61, 251–263.
• Järup, L., Hellström, L., Alfvén, T., Carlsson, M., Grubb, A., Persson, B., Pettersson, C., Spång, G., Schütz, A., Elinder, C., 2000. Low level exposure to cadmium
and early kidney damage: the OSCAR study. Occup. Environ. Med. 57, 668–672.
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Inference from
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• Madala, S., Nadavala, S.K., Vudagandla, S., Boddu, V.M., Abburi, K., 2013. Equilibrium, kinetics and thermodynamics of Cadmium (II) biosorption on to composite
chitosan biosorbent. Arab. J. Chem.
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• Pal, P., Pal, A., 2017a. Surfactant-modified chitosan beads for cadmium ion adsorption. Int. J. Biol. Macromol. 104, 1548–1555.
• Pal, P., Pal, A., 2017b. Enhanced Pb2+ removal by anionic surfactant bilayer anchored on chitosan bead surface. J. Mol. Liq. 248, 713–724.
• Siahkamari, M., Jamali, A., Sabzevari, A., Shakeri, A., 2017. Removal of lead(II) ions from aqueous solutions using biocompatible polymeric nano-adsorbents: A
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Results and
Discussion
Inference from
the study

Results and
Discussion
Inference from
the study
79
Acknowledgements
My sincere thanks to
• School of Environmental Science and Engineering (SESE),
• Civil Engineering Department
and
• Central Research Facility (CRF), IIT Kharagpur
for providing the instrumental facility and financial support to carry out this research.
• My supervisor Prof. Anjali Pal, HoS Prof. M.M. Ghangrekar and former HoS Prof. J. Bhattacharya,
research scholar coordinator Prof. Sudha Goel and all my DSC members for giving their valuable time,
guidance and support.
• All my lab mates from SESE and from civil engineering department, all the staff members for helping
during the PhD tenure.

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