Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 1 Volume 2, Issue 1
Investigating the surface properties of agro-waste derived activated carbon and its versatile
applications to treat water and wastewater via Capacitive Deionization
Madhu Agarwal
a*
, Karishma Maheshwari
a
a
Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur
Jaipur 302017, India
* Corresponding author. Tel.: +91 9549654166 E-mail address: magarwal.chem@mnit.ac.in; madhunaresh@gmail.com
Abstract
Water scarcity is a significant issue faced by most of the population in today’s era, basically due to contamination of water
bodies by discharging the waste stream without prior treatment. For instance, textile waste, reverse osmosis (RO) reject,
chemical industries waste, paper industry waste stream, etc., are the prominent sources from where the waste streams are
discarded in huge quantities. These streams have several harmful effects on humans, animals, plants, and other living
organisms and, therefore, need dire attention for treatment. Several approaches are available in the giant research history;
however, capacitive deionization (CDI) is a recent boon in the water treatment area. Henceforth, the present study aims at
exploring the versatility of CDI for RO reject (R-RO) and Congo red dye (D-CR) treatment via developed biochar based
activated carbon electrode. The study involves characterization of developed material which reveals its high suitability for
sorption of ions over surface due to porous attributes, specific surface area of 268 m
2
/g, presence of graphitic carbon, and
the existence of functional groups comprising carbon, nitrogen, oxygen, hydrogen, etc. vibrations in the structure.
Moreover, the electrochemical performance suggests that developed electrode had a potentially strong specific capacitance
of 58.23 F/g. It was evaluated that a strong sorption capacity for 22.98 mg/g in case of salt whereas for D-CR around 140.8
mg/g was reported. Therefore, it was proposed that biochar based electrode had a great potential for application in water
and wastewater. To the author’s perspective, for achieving enhanced removal the material will need further surface
modifications which will be the future scope of the work.
Keywords: sorption; application; isotherms; electro-chemical aspects; capacity.
1. Introduction
Water scarcity is the most prominent and enormously
augmenting issue in today’s era in front of the whole
world. This major scarcity is due to the exponentially
increasing demands of fresh water and continuously
growing water contaminations. Whole world is suffering
from this issue as only 0.6 % of water is overall
available as clean drinking water. Evaluating the
availability of fresh water, researchers have tried their
most to explore the techniques for treating the
contaminated streams of water from widely adopted
technologies or industries, namely, salt concentrated and
dye contaminated effluent wastewater streams (Ma et al.,
2022; Wang et al., 2022; Zhang and Li, 2022). These
streams need to be monitored as they are highly
hazardous to the environmental health as they are
directly disposed of in the ground leading to impact
living species (Gorri and Urtiaga, 2017; Naidu et al.,
2017; Taylor et al., 2015). Moreover, the discharged
stream has various compositions in it, as there could be
salts, dyes, heavy metals, etc. One of the investigator
reported the actual physicochemical properties of RO
reject revealing high salinity with presence of salt ions
like chloride (1300 mg/L), magnesium (30 mg/L),
potassium (80 mg/L), sulfate (2500 mg/L), nitrate (20
mg/L), etc. and other contaminating elements like silica
around 5 mg/L (Sahinkaya et al., 2018). Moreover,
similarly another research evaluated the composition of
RO concentrate from San Jaoaquin valley sample
comprising exteremely huge TDS up to 30,000 mg/L
with presence of Na, Mg, Ca, etc. ions (Rahardianto et
al., 2010).
The various water and wastewater treatment approaches
includes membrane filtration (Rajaeian et al., 2013; Sun
et al., 2019; Xiao et al., 2021), electrical driven
techniques (Thakur and Mondal, 2017; Thamilselvan et
al., 2018; Zhang et al., 2011), adsorption (Agarwal et al.,
2019; Anantha et al., 2020; Madan et al., 2019;
Maneerung et al., 2016; Sharma et al., 2019; Zhang et
al., 2019), thermal approaches (Bamufleh et al., 2017; Li
et al., 2018; Naidu et al., 2018, 2017; Sanmartino et al.,
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 2 Volume 2, Issue 1
2017), etc. (Article, 2009; Cheng et al., 2021; Dubey et
al., 2019; Maheshwari and Agrawal, 2020; Rajamani,
2019; Rioyo et al., 2018; Selvaraj et al., 2020;
Subramani and Jacangelo, 2014). With the similar view,
in our previous investigation dye contaminated (Congo
red dye) wastewater with initial concentration of 10 ppm
was treated with synthesized adsorbent proposing a great
potential in terms of energy statistics (3.4 kWh) and
efficacy (97.7 %) (Maheshwari et al., 2020).
Furthermore, electrocoagulation was examined for acid
green 20 and reactive yellow 17 treatment proposing
strong efficacies with 92.1 and 86.5 % in a binary
system reporting a current density of 100 mA/cm
2
.
Therefore, it can be suggested that electrochemical
treatment could be significant solution for treatment for
binary system (Moneer et al., 2021). Moreover, there
were membrane techniques adopted for salt removal and
dye irradiation. For instance, Lai et al. (2016) fabricated
graphene oxide-based thin-film NF membrane. They
investigated the attenuation of salts, reporting 95 %, 91
%, and 62 % rejections for sodium sulphate, magnesium
sulphate, and magnesium chloride, respectively (Lai et
al., 2016). A recent study by Sun et al. (2019) supported
the fact by investigating the NF 90 and NF 270
membranes for inorganic salt removal. The research
revealed that significantly massive ion rejections were
reached in the case of NF 90 with 99 %, 98 %, 96 %,
and 84 % for SO
4
2-
, F
-
, Cl
-
, and NO
3-
, respectively (Sun
et al., 2019). However, these instances suggest that
technologies possess strong outputs in terms of removal
but are inefficient considering aspects like energy
consumption. Henceforth, an energy-efficient system is
needed for removal of water contaminating elements like
dyes, and salts as they are heavily discharged in the
natural water bodies. Apart from the stated conventional
techniques, capacitive deionization (CDI) has been
explored as a new and advancement to the areas of water
remediation and wastewater treatment.
There are versatile applications of the CDI process for
water treatment with the advantage of being
environmentally friendly, cost-efficient, lower energy
statistics, easy to handle design, facile electrode
regeneration, and limited voltage implementation (Xing
et al., 2020). The approach has the essential operation of
sorbing ions from the simulated stream using a
connected system of electrodes applying a DC power
(Ding et al., 2019). The practical reason for removing
ions is forming an electrical double layer (EDLC) due to
electrostatic force of attractions between electrodes
surface and existing ions in the stream. Various flow
architectures are used, namely, flow-by, flow-through,
inverted CDI, hybrid CDI, membrane CDI, intercalation
CDI, and the research is still ongoing (Maheshwari and
Agrawal, 2020). The most prominent property to be
considered for CDI is the electrode’s material, which
implies double layer formation over the surface of the
electrode, enhancing desalination properties. Therefore,
the selection of active material is its fundamental
parameter to record performance and carbon, and its
extended families are well-known materials for specific
surface area and morphology (Xie et al., 2018a). So
activated carbon is the most widely reported material for
the fabrication of electrodes (Moneer et al., 2021). Not
only the accessibility for ion sorption but the activated
carbon is said to have potentially electrochemical solid
properties (Xie et al., 2018b).
Activated carbon is the widely used material for
removing dyes, pharmaceuticals, heavy metals, etc., due
to huge surface accessibility (Xie et al., 2018b).
Therefore, CDI would be suitable for removing ionic
species like salts ions. There were many investigations
performed in the literature using activated carbon. For
instance, Kyaw et al. (2021) used dry date palm leaflets
to synthesize activated carbon modified with sodium
hydroxide implemented for fabrication of electrode
treating 100 mg/L NaCl solution implementing 1.2 V
reporting 5.38 mg/g sorption capacity (Kyaw et al.,
2021). Moreover, another researcher also used peanut
shells after impregnation with phosphoric acid for
electrode's synthesis, revealing a sorption performance
of 65 mg/g for 1000 mg/L TDS of the inlet, providing
120 min of electrosorption duration (Wu et al., 2019).
Similarly, another investigation was reported on the
feasibility of pine pollen-derived biomass to develop
activated carbon used for fabricating electrodes. The
investigation reported 7.25 mg/g capacity for 50 µs/cm
inlet concentration of NaCl solution at the operating
voltage of 2.0 V (Liu et al., 2019). A similar pattern was
observed by a study synthesizing activated carbon from
sugar cane bagasse and chemically activating with zinc
chloride reporting a significant increase in capacitance
from 12 to 86 F/g. The sorption capacity increased from
48 – 74 % operating at 1.2 V for the initial concentration
of 600 mg/L (Lado et al., 2017). Therefore, the surface
impregnations and interface modifications are in trend
due to drastic enhancements in material properties like
surface area, porosity, etc. (Rambabu et al., 2020). These
reduce the system's cost and lead to the sustainable
pathway of utilizing agro-based waste discharged
directly into the environment. Therefore, there is a dire
need to implement such materials for electrode
fabrication as it's a green process. The modality for pore
distribution supports the fact that the synthesized
activated carbon can range from 2 mm to 100 mm, i.e.
microporous ( lesser than or equal to 2 mm), mesoporous
( greater than 2 to less than 50 mm ), and macro-porous
(50 mm and greater) divisions (Rambabu et al., 2020).
Moreover, when the base material is synthesized when
clubbed with impregnations coatings, doping can
drastically enhance the desalting performance of the
electrode. They have disordered arrangements with
surface areas ranging from 300 to 5000 m
2
/g.
Henceforth in the present article, the versatility of CDI
has been explored for RO reject (R-RO) and Congo red
dye (D-CR) treatment via developed biochar based
activated carbon electrode. The study involves
characterization of developed material which checks its
suitability for sorption of ions over surface including
Brunauer–Emmett–Teller (BET) for evaluating specific
surface area, Scanning electron microscope (SEM) for
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 3 Volume 2, Issue 1
analysing morphology with energy dispersive
spectroscopy (EDS) for tabulating elemental
composition, X-ray diffraction (XRD) for observing the
nature of developed sample, Fourier transform infrared
(FTIR) for assessing the functional group presence, and
X-ray photoelectron spectroscopy (XPS) for evaluation
of oxidation states. Moreover, the electrochemical
performance were determined, namely, cyclic
voltammetry (CV) and electrochemical impedance
spectroscopy (EIS). The biochar based electrode was
fabricated for the application in water and wastewater.
The possible mechanism was also drawn out evaluating
the key parameters behind sorption of pollutants over the
surface of fabricated electrodes on the application of
potential voltage.
2. Materials and methodology
2.1 Materials
The walnut shells discarded from the grocery stores were
procured from local market in Jaipur, Rajasthan. The
collected waste shells were washed and crushed into
powdered material using a crusher. The powdered
material was carbonized at a high temperature of 400 ℃
for about 3.5 h.
Figure 1. Carbonization of walnut shell powder
derived activated carbon
Figure 2. Experimental Illustrations of CDI set-up
2.2 Characterization and electrochemical Aspects
For surface characteristics analysis, BET approach
was implemented to evaluate the surface area
wherein the synthesized material was kept for
degassing around 800 ℃ at 6 h of contact time.
Moreover, for functional group assessment and
textural property assessment, FTIR and SEM
equipped with EDS was performed using spectrum 2
machines and Nova Nano SEM - 450 device. The
FTIR was scanned in the range of 4000 - 400 cm
-1
wavelength,
and SEM was imaged at 15 kV voltage at vacuum
pressure. XPS analysis was recorded via detector
which is multichannel having Mg-Ka source with
model number 5700 operated around 15 kV. PAN
X’pert diffractometer was used to examine the XRD
pattern with operating conditions at scan rate of
2°/min in between 5 to 80 degrees. The machine was
equipped with CuKα radiations workable around 40
kV and 40 mA from Netherlands.
In the exact string, electrochemical characterization
was assessed using a Bio-logic workstation with
model number 092-CHAS-T-092–150 purchased
from France having SP-150 channel 3 electrode
system of the reference electrode, working electrode
(synthesized electrode), and counter electrode. The
electrical connections were established connected
with electrical wire whereas 1 M NaCl was used as
an electrolyte in the functioning cell, and the data
was decoded using EC lab software.
2.3 Sorption process for dye and salt removal
Batch mode electrosorption study for dye removal
was done using 100 mL dye sample volume with 10
mg/L initial concentration to 50 mg/L and 15 to 120
min electrosorption time. Moreover, for salt
contaminated stream 1000 – 2000 mg/L initial
concentration was selected as feed to the system with
same electrosorption time and volume to be treated.
The coated activated carbon electrodes were
electrically connected to the two ends via electrical
wire using a direct current source, wherein a 100 mL
size beaker was kept over magnetic stirrer as
depicted in fig 2. A UV spectrophotometer was used
to evaluate the feed and treated water concentration
of dye contaminated water stream by developing a
calibration curve based on the standards in the
concentration range from 0 to 100 mg/L. Moreover,
the salt concentration was measured with Hanna’s
multimeter device.
The efficacies for both the cases were evaluated
based on equation (1) given below:
Where C
0
and C
e
symbolizes the inlet and outlet
concentrations in the system respectively. For
analysing the equilibrium states, isotherm models
namely, Langmuir, Freundlich, and Temkin models
were implemented to fit the batch equilibrium
experimental data obtained. Table 1 shows the
mathematical equations with their assumptions used
in the three models. Moreover, the kinetic models of
the system has been tabulated in Table 2
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 4 Volume 2, Issue 1
Table 1: Isotherm Models for capacitive removal of
pollutants
3. Results and interpretation
3.1 Characterization of the developed and modified
material
The scan patterns obtained were as shown in figure 3
for BET, SEM with EDS analysis, FTIR, XRD and
XPS of synthesized. The corresponding BET image
suggests that the specific surface areas were observed
to be 268 m
2
/g as shown in figure 3 (a). The SEM
image pattern suggests that the sample has higher
porous cavities, as visible in figure 3 (b) revealing
the presence of carbon, nitrogen, and oxygen
depicted in the EDS characterization shown in figure
3 (c). The sample has huge unevenly distributed
porous holes, which hypothesize that material is
suitable for higher sorption of ions. However, the
FTIR characterization pattern as shown in figure 3
(d) reveals that the peaks were observed at 2657.3
cm
-1
, 2318.83 cm
-1
, 2118.96 cm
-1
, 1998.64 cm
-1
,
1747.79 cm
-1
, 1554.04 cm
-1
, 1038.07 and 779.06 cm
-
1
which corresponds to O-H stretching, methyl group
vibrations, C-H stretching, and carboxyl group
presence for all the synthesized materials
(Maheshwari et al., 2021). Henceforth, analysing the
morphology and characterization of synthesized
materials, the sample was best suited for the sorption
of pollutants which can easily deionize on
application of potential
. Moreover, the XRD patterns
as shown in in figure 3 (e) reveals that carbon had a
sharp peak 2 theta angle of 27.40° proposing the
existence of carbon element in the similar manner (Li
et al., 2017). Another characterization of XPS
supporting the XRD pattern that carbon was present
in the form of C-C, C-O-C, and O-C=O with the
binding energy 283.5, 286.1, and 288.3 eV as shown
in figure 3 (f).
3.2 Electrochemical aspects of the developed and
modified material
The electrochemical aspects were drawn to evaluate
the capacitance and resistance of the fabricated
electrode. Firstly, the CV was performed applying
the potential voltage from -0.60 V to 1.00 V varying
the scan rates from 10 to 50 mvps with the difference
of 10 mvps. The obtained analysis has been plotted
in figure 4 (a) proposing the strong specific
capacitance at 10 mvps scan rate to be around 58 F/g.
As visible in the graphical representation, there is a
hysteresis curve for all the scan rates from 10 to 50
mvps. However, it can also be seen that lowest scan
rate has a stronger rectangular geometrical behaviour
revealing the capacitive nature of the electrode. This
might be due to the fact that on employing higher
contact time one will obviously found the higher rate
of ionic adsorption over the adhering surface of
fabricated electrode. For the same, evidences were
reported in literature by sufiani et al. (2020) who
experimented to evaluate the insights of
electrochemical process by varying the scan rates
from 5 to 100 mvps. The investigator reported that at
5 mvps the electrode possess relatively higher
specific capacitance than higher scan rates. The
reason behind such process was explained to be the
greater time provides higher sorption of deionized
ions resulting into decreasing pattern of specific
capacitance with increasing scan rates (Sufiani et al.,
2020).
Table 2: Kinetic Models for capacitive removal of
pollutants
Model
Mathematical
representation
of Model
Brief of the
Isotherm Model
Reference
Pseudo
First
Order
kinetics
This model
suggests there is
sorption of solute
entities from the
solution over the
surface of sorbent.
(Maheshwari
et al., 2020)
Pseudo
second
order
kinetics
It proposes that
there is a direct
relation between
the sorption of
pollutants over the
active sites and
vacant sites.
(Agarwal and
Singh, 2017)
Model
Mathematical
representation
of Model
Brief of the
Isotherm Model
Reference
Langmuir
Isotherm
The Langmuir
model suggests that
there are
homogenous active
sites that leads to
monolayer
formations
proposing a
dynamic
equilibrium within
the molecules.
(Maheshwari
et al., 2020)
Freundlich
Isotherm
This isotherm
proposes the
existence of multi-
layer coverage and
the system is
assumed to be
heterogeneous in
nature. There is
uneven distribution
of pores over the
surface of
adsorbent.
(Agarwal
and Singh,
2017)
Temkin
Isotherm
)
It assumes that heat
of sorption is
dependent on
interaction of
adsorbent and
liquid.
(Singh et al.,
2019)
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 5 Volume 2, Issue 1
Moreover, resistance being another prominent factor
for evaluating the electrochemical performance was
examined as represented in figure 4 (b) with the
frequency from 0.01 to 10000 Hz. The potential
voltage was kept to be 0.1 V for drawing out the EIS.
The resulted obtained states that fabricated electrode
had small resistance property of 5.7 Ω which was
calculated based on the small circular section
revealing lesser polarization in the similar way to the
study by (Xie et al., 2018a). Furthermore, as seen
from the graphical analysis we can observe that on
increase in the frequency lead the curve towards a
straight pattern proposing the ideal nature with
capacitive performance. The similar behaviour was
reported in study by (Li et al., 2020). From the
electrochemical aspects and calculations, it can be
proposed that fabricated electrode revealed to have a
greater capacitive nature whereas the developed
electrode has high suitability in terms of resistances.
3.3 Desalination performances of synthesized electrode
For developed electrodes, desalination performance
was significantly increased up to 60 min of sorption
period. After that, the curve was slightly leading
toward a constant % desalination, as shown in Figure
5.
It can be seen that on the increase in electro-sorption
time, the % desalination increases for a constant inlet
concentration of 1000 mg/L due to more incredible
retention time provided for sorption of ions over the
electrode surface, forming an electrical double layer.
Similar patterns were observed by Hu et al. (2018) for
nitrate removal via film electrodes (Hu et al., 2018).
Another investigation by Tsai (2021) supports our
finding with the desalination performance of m-CDI
for concentrated stream reporting 0.2 mmol/g
desalination capacity (Tsai et al., 2021).
Moreover, another important factor of sorption
capacity was examined as shown in figure 5 (c). The
results revealed that higher sorption capacity of 22.98
mg/g electrodes.
3.4 Textile effluent removal
As represented in the figure 6 (a and b), the
experiments were by varying inlet concentration and
electro-sorption duration, respectively. It was
revealed that on priory enhancing the inlet
concentrations of CRD to the system lead to
decreased in sorption performance with the constant
contact time of 2 h. This might be due to the lesser
accessibility of adsorption sites. The similar study
was reported by Xu et al.(2018b) wherein it was
reported that increase in inlet concentration reported
to decrease in % removal. Apart from this, variation
in sorption time range resulted in increased %
removal for constant inlet concentrations indicating
higher performance due to porous surface in similar
way by (Nasseh et al., 2020).
The kinetic model of sorption was fitted and reported
as shown in figure 7 revealing the best fit of second
order model with R
2
to be 0.99 and RMSE (error)
value to be around 0.27. This proposes that initial
concentration has a major role to reach the
equilibrium which has been similar to the experiment
by (Wang et al., 2018). The parameters are evaluated
in table 3.
Isotherms were fitted to the equilibrium data which
stated that the Langmuir isotherm is the best fit
revealing R
2
to be 0.99 as shown in figure 8, which
proposes there is prominently monolayer sorption of
ions over the surface of electrodes revealing root
mean square error to be 0.32 in the similar manner
evaluated by (Renu et al., 2018). The prominent
parameters of isotherm model were calculated as
shown in table 4.
3.5 Textile effluent removal
As represented in the figure 6 (a and b), the experiments
were by varying inlet concentration and electro-sorption
duration, respectively. It was revealed that on priory
enhancing the inlet concentrations of CRD to the system
lead to decreased in sorption performance with the
constant contact time of 2 h. This might be due to the
lesser accessibility of adsorption sites. The similar study
was reported by Xu et al.(2018b) wherein it was reported
that increase in inlet concentration reported to decrease
in % removal. Apart from this, variation in sorption time
range resulted in increased % removal for constant inlet
concentrations indicating higher performance due to
porous surface in similar way by (Nasseh et al., 2020).
The kinetic model of sorption was fitted and reported as
shown in figure 7 revealing the best fit of second order
model with R
2
to be 0.99 and RMSE (error) value to be
around 0.27. This proposes that initial concentration has
a major role to reach the equilibrium which has been
similar to the experiment by (Wang et al., 2018). The
parameters are evaluated in table 3.
Table 3: Sorption kinetic model Parameters for
Capacitive removal of CRD
Table 4: Sorption Isotherm model for capacitive
removal of CRD
Langmuir
Model
Parameters
q
m
k
L
R
2
RMSE
140.84 mg/g
0.04 L/g
0.99
0.32
Freundlich
Model
Parameters
K
f
n
R
2
RMSE
2.05 mg
1-
1/n
L
1/n
/g
12.06
0.98
0.43
Temkin
Model
Parameters
a
b
R
2
RMSE
0.42
0.04
0.97
0.52
Pseudo First Order
Kinetics
Second Order Kinetics
K
1
=0.01
q
e
=10.95 mg/g
R
2
=0.98
RMSE=0.79
q
e
=20.80 mg/g
K
2
=0.002
R
2
=0.99
RMSE=0.27
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 6 Volume 2, Issue 1
Figure 3. (a) BET, (b) SEM, (c) EDS, (d) FTIR, (e) XRD, and (f) XPS characterization of developed
material
Figure 4. (a) CV and (b) EIS characterization of developed material
(b)
(c)
(d)
(e)
(f)
(a)
(b)
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 7 Volume 2, Issue 1
Figure 5. (a) Desalinating RO Reject via developed
electrode
Isotherms were fitted to the equilibrium data which
stated that the Langmuir isotherm is the best fit
revealing R
2
to be 0.99 as shown in figure 8, which
proposes there is prominently monolayer sorption of
ions over the surface of electrodes revealing root
mean square error to be 0.32 in the similar manner
evaluated by (Renu et al., 2018). The prominent
parameters of isotherm model were calculated as
shown in table 4.
Figure 6. (a) Decolorizing Dye effluent via developed
electrode
Figure 7. (a) Kinetics of the capacitive dye removal
Figure 8. (a) Isotherms of the capacitive dye removal
4. Conclusion
The present study revealed that CDI has versatility
for its applications in water and wastewater
treatment. It was explored that the CDI had a great
potential to treat RO reject (R-RO) and Congo red
dye (D-CR). The treatment was done via developed
biochar based activated carbon electrode. The
investigation revealed that surface characteristics of
the developed material has high suitability for
sorption of ions over surface due to porous attributes,
specific surface area of 268 m
2
/g, presence of
graphitic carbon, and the existence of functional
groups comprising carbon, nitrogen, oxygen,
hydrogen, etc. vibrations in the structure. Moreover,
the electrochemical performance suggested that
developed electrode had a potentially strong specific
capacitance of 58.23 F/g. It was evaluated that a
strong sorption capacity for 22.98 mg/g in case of
salt whereas for D-CR around 140.8 mg/g was
reported. Therefore, it was proposed that biochar
based electrode had a great potential for application
in water and wastewater. Furthermore, it was
examined that the selectivity of the electrode for
particular pollutant treatment will be the future work
of recommendation, which will be based on the
surface modifications and bimetallic nanoparticles
incorporations.
Acknowledgements
Authors would like to thank MRC, MNIT Jaipur for
the characterization done in the present article. Also,
the authors like to thanks MNIT Jaipur for providing
the laboratory facilities to research and explore new
approaches in the field.
References
Agarwal, M., Kumari, P., Dubey, S., Gupta, R.,
Kumar Dohare, R., 2019. Adsorption Behavior of
Azo Dyes on Carbon Nanotubes Grown on Alumina:
Process Optimization, Kinetics, and Equilibrium
Study. J. Environ. Eng. (United States) 145, 1–16.
https://doi.org/10.1061/(ASCE)EE.1943-
7870.0001482
Agarwal, M., Singh, K., 2017. Removal of copper ,
cadmium , and chromium from wastewater by
modified wheat bran using Box – Behnken design :
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 8 Volume 2, Issue 1
Kinetics and isotherm. Sep. Sci. Technol. 00, 1–14.
https://doi.org/10.1080/01496395.2017.1417316
Anantha, M.S., Olivera, S., Hu, C., Jayanna, B.K.,
2020. Environmental Technology & Innovation
Comparison of the photocatalytic , adsorption and
electrochemical methods for the removal of cationic
dyes from aqueous solutions. Environ. Technol.
Innov. 17, 100612.
https://doi.org/10.1016/j.eti.2020.100612
Article, R., 2009. Application of Ultrasonic
Technology for Water and Wastewater Treatment 38,
1–17.
Bamufleh, H., Abdelhady, F., Baaqeel, H.M., El-
Halwagi, M.M., 2017. Optimization of multi-effect
distillation with brine treatment via membrane
distillation and process heat integration. Desalination
408, 110–118.
https://doi.org/10.1016/j.desal.2017.01.016
Cheng, X., Qin, Y., Ye, Y., Chen, X., Wang, K.,
Zhang, Y., Figoli, A., Drioli, E., 2021. Finely
tailored pore structure of polyamide nanofiltration
membranes for highly-efficient application in water
treatment. Chem. Eng. J. 417, 127976.
https://doi.org/10.1016/j.cej.2020.127976
Ding, Z., Xu, X., Li, Y., Wang, K., Lu, T., Pan, L.,
2019. Significantly improved stability of hybrid
capacitive deionization using nickel
hexacyanoferrate/reduced graphene oxide cathode at
low voltage operation. Desalination 468, 114078.
https://doi.org/10.1016/j.desal.2019.114078
Dubey, S., Agrawal, M., Gupta, A.B., 2019.
Advances in coagulation technique for treatment of
fluoride-contaminated water: A critical review. Rev.
Chem. Eng. 35, 109–137.
https://doi.org/10.1515/revce-2017-0043
Gorri, D., Urtiaga, A., 2017. Ef fi cient treatment of
per fl uorohexanoic acid by nano fi ltration followed
by electrochemical degradation of the NF
concentrate Alvaro 112, 147–156.
https://doi.org/10.1016/j.watres.2017.01.043
Hu, C., Dong, J., Wang, T., Liu, R., Liu, H., Qu, J.,
2018. Nitrate electro-sorption / reduction in
capacitive deionization using a novel Pd / NiAl-
layered metal oxide fi lm electrode. Chem. Eng. J.
335, 475–482.
https://doi.org/10.1016/j.cej.2017.10.167
Kyaw, H.H., Al-mashaikhi, S.M., Tay, M., Myint, Z.,
Al-harthi, S., Al-abri, M., 2021. Activated carbon
derived from the date palm leaflets as multifunctional
electrodes in capacitive deionization system. Chem.
Eng. Process. Process Intensif. 108311.
https://doi.org/10.1016/j.cep.2021.108311
Lado, J.J., Zornitta, R.L., Calvi, F.A., Martins, M.,
Anderson, M.A., Nogueira, F.G.E., Ruotolo, L.A.M.,
2017. Enhanced capacitive deionization desalination
provided by chemical activation of sugar cane
bagasse fly ash electrodes. J. Anal. Appl. Pyrolysis
126, 143–153.
https://doi.org/10.1016/j.jaap.2017.06.014
Lai, G.S., Lau, W.J., Goh, P.S., Ismail, A.F., Yusof,
N., Tan, Y.H., 2016. Graphene oxide incorporated
thin fi lm nanocomposite nano fi ltration membrane
for enhanced salt removal performance. DES 387,
14–24. https://doi.org/10.1016/j.desal.2016.03.007
Li, D., Ning, X. an, Yuan, Y., Hong, Y., Zhang, J.,
2020. Ion-exchange polymers modified bacterial
cellulose electrodes for the selective removal of
nitrite ions from tail water of dyeing wastewater. J.
Environ. Sci. (China) 91, 62–72.
https://doi.org/10.1016/j.jes.2020.01.002
Li, F., Huang, J., Xia, Q., Lou, M., Yang, B., Tian,
Q., Liu, Y., 2018. Separation and Puri fi cation
Technology Direct contact membrane distillation for
the treatment of industrial dyeing wastewater and
characteristic pollutants. Sep. Purif. Technol. 195,
83–91. https://doi.org/10.1016/ j.seppur.2017.11.058
Li, S., Han, K., Li, J., Li, M., Lu, C., 2017.
Preparation and characterization of super activated
carbon produced from gulfweed by KOH activation.
Microporous Mesoporous Mater.
https://doi.org/10.1016/j.micromeso.2017.02.052
Liu, Q., Li, X., Wu, Y., Qing, M., Tan, G., Xiao, D.,
2019. Pine pollen derived porous carbon with
efficient capacitive deionization performance.
Electrochim. Acta 298, 360–371.
https://doi.org/10.1016/j.electacta.2018.12.072
Ma, J., Shen, G., Zhang, R., Niu, J., Zhang, J., Wang,
X., Liu, J., Li, X., Liu, C., 2022. Small Particle Size
Activated Carbon Enhanced Flow Electrode
Capacitive Deionization Desalination Performances
by Reducing the Interfacial Concentration
Difference. Electrochim. Acta 431, 140971.
https://doi.org/10.1016/j.electacta.2022.140971
Madan, S., Shaw, R., Tiwari, S., Kumar, S., 2019.
Applied Surface Science Adsorption dynamics of
Congo red dye removal using ZnO functionalized
high silica zeolitic particles. Appl. Surf. Sci. 487,
907–917.
https://doi.org/10.1016/j.apsusc.2019.04.273
Maheshwari, K., Agrawal, M., 2020. Advances in
capacitive deionization as an effective technique for
reverse osmosis reject stream treatment. J. Environ.
Chem. Eng. 8, 104413. https://doi.org/10.1016/
j.jece.2020.104413
Maheshwari, K., Agrawal, M., Gupta, A.B., 2021.
Experimental investigation for treating the RO reject
stream through capacitive deionization. Sep. Purif.
Technol. 276, 119261. https://doi.org/10.1016/
j.seppur.2021.119261
Maheshwari, K., Solanki, Y.S., Ridoy, M.S.H.,
Agarwal, M., Dohare, R., Gupta, R., 2020. Ultrasonic
treatment of textile dye effluent utilizing microwave-
assisted activated carbon. Environ. Prog. Sustain.
Energy. https://doi.org/10.1002/ep.13410
Maneerung, T., Liew, J., Dai, Y., Kawi, S., Chong,
C., Wang, C., 2016. Bioresource Technology
Activated carbon derived from carbon residue from
biomass gasification and its application for dye
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 9 Volume 2, Issue 1
adsorption : Kinetics , isotherms and thermodynamic
studies 200, 350–359.
https://doi.org/10.1016/j.biortech.2015.10.047
Moneer, A.A., El-mallah, N.M., El-sadaawy, M.M.,
Khedawy, M., Ramadan, M.S.H., 2021. Kinetics ,
thermodynamics , isotherm modeling for removal of
reactive Red 35 and disperse yellow 56 dyes using
batch bi-polar aluminum electrocoagulation.
Alexandria Eng. J. 60, 4139–4154.
https://doi.org/10.1016/j.aej.2021.02.061
Naidu, G., Jeong, S., Choi, Y., Vigneswaran, S.,
2017. Membrane distillation for wastewater reverse
osmosis concentrate treatment with water reuse
potential. J. Memb. Sci. 524, 565–575.
https://doi.org/10.1016/ j.memsci.2016.11.068
Naidu, G., Zhong, X., Vigneswaran, S., 2018.
Comparison of membrane distillation and freeze
crystallizer as alternatives for reverse osmosis
concentrate treatment. Desalination 427, 10–18.
https://doi.org/10.1016/j.desal.2017.10.043
Nasseh, N., Arghavan, F.S., Rodriguez-Couto, S.,
Hossein Panahi, A., 2020. Synthesis of
FeNi3/SiO2/CuS magnetic nano-composite as a
novel adsorbent for Congo Red dye removal. Int. J.
Environ. Anal. Chem. 7319.
https://doi.org/10.1080/03067319.2020.1754810
Rahardianto, A., Mccool, B.C., Cohen, Y., 2010.
Accelerated desupersaturation of reverse osmosis
concentrate by chemically-enhanced seeded
precipitation. DES 264, 256–267.
https://doi.org/10.1016/j.desal.2010.06.018
Rajaeian, B., Rahimpour, A., Tade, M.O., Liu, S.,
2013. Fabrication and characterization of polyamide
thin film nanocomposite (TFN) nanofiltration
membrane impregnated with TiO2 nanoparticles.
Desalination 313, 176–188.
https://doi.org/10.1016/j.desal.2012.12.012
Rajamani, S., 2019. Sustainable tannery effluent
treatment system with TDS management. 35th
IULTCS Congr. 2019 "Benign by Des. Leather -
Futur. Through Sci. Technol. 1–6.
Rambabu, K., Bharath, G., Hai, A., Luo, S., Liao, K.,
Abu, M., Banat, F., Naushad, M., 2020.
Development of watermelon rind derived activated
carbon / manganese ferrite nanocomposite for
cleaner desalination by capacitive deionization 272.
Renu, Agarwal, M., Singh, K., 2018. Removal of
copper, cadmium, and chromium from wastewater by
modified wheat bran using Box–Behnken design:
Kinetics and isotherm. Sep. Sci. Technol. 53, 1476–
1489.
https://doi.org/10.1080/01496395.2017.1417316
Rioyo, J., Aravinthan, V., Bundschuh, J., Lynch, M.,
2018. Research on ‘high-pH precipitation treatment’
for RO concentrate minimization and salt recovery in
a municipal groundwater desalination facility.
Desalination 439, 168–178.
https://doi.org/10.1016/j.desal.2018.04.020
Sahinkaya, E., Sahin, A., Yurtsever, A., Kitis, M.,
2018. Concentrate minimization and water recovery
enhancement using pellet precipitator in a reverse
osmosis process treating textile wastewater. J.
Environ. Manage. 222, 420–427.
https://doi.org/10.1016/ j.jenvman.2018.05.057
Sanmartino, J.A., Khayet, M., García-Payo, M.C.,
El-Bakouri, H., Riaza, A., 2017. Treatment of
reverse osmosis brine by direct contact membrane
distillation: Chemical pretreatment approach.
Desalination 420, 79–90.
https://doi.org/10.1016/j.desal.2017.06.030
Selvaraj, M., Hai, A., Banat, F., Haija, M.A., 2020.
Application and prospects of carbon nanostructured
materials in water treatment: A review. J. Water
Process Eng. 33, 100996. https://doi.org/10.1016
/j.jwpe.2019.100996
Sharma, A., Syed, Z., Brighu, U., Gupta, A.B., Ram,
C., 2019. Adsorption of textile wastewater on alkali-
activated sand. J. Clean. Prod. 220, 23–32.
https://doi.org/10.1016/j.jclepro.2019.01.236
Singh, Y., Agarwal, M., Gupta, S., Shukla, P., 2019.
Journal of Environmental Chemical Engineering
Application of synthesized Fe / Al / Ca based
adsorbent for de fl uoridation of drinking Water and
its signi fi cant parameters optimization using
response surface methodology. J. Environ. Chem.
Eng. 7, 103465.
https://doi.org/10.1016/j.jece.2019.103465
Subramani, A., Jacangelo, J.G., 2014. Treatment
technologies for reverse osmosis concentrate volume
minimization : A review. Sep. Purif. Technol. 122,
472–489.
https://doi.org/10.1016/j.seppur.2013.12.004
Sufiani, O., Tanaka, H., Teshima, K., Machunda,
R.L., Jande, Y.A.C., 2020. Enhanced electrosorption
capacity of activated carbon electrodes for deionized
water production through capacitive deionization.
Sep. Purif. Technol. 247.
https://doi.org/10.1016/j.seppur.2020.116998
Sun, L., Zhou, J., Mai, Z., Zhang, Z., 2019.
Experimental Study on Removing Inorganic Salts
from Groundwater Through Nanofiltration
Membrane Process Under Low Operating Pressure
Key Words :
Taylor, P., Bazrafshan, E., Alipour, M.R., Mahvi,
A.H., 2015. Desalination and Water Treatment
Textile wastewater treatment by application of
combined chemical coagulation , electrocoagulation ,
and adsorption processes 37–41.
https://doi.org/10.1080/19443994.2015.1027960
Thakur, L.S., Mondal, P., 2017. Simultaneous
arsenic and fluoride removal from synthetic and real
groundwater by electrocoagulation process:
Parametric and cost evaluation. J. Environ. Manage.
190, 102–112. https://doi.org/10.1016/
j.jenvman.2016.12.053
Thamilselvan, A., Govindan, K., Nesaraj, A.S.,
Maheswari, S.U., Oren, Y., Noel, M., James, E.J.,
2018. Investigation on the effect of organic dye
Proceedings of CUChE Alumni Symposium 2022
On “Circular Economy on Sustainable Basis: The Role of Chemical Engineers”
CUChEAA ISBN: 978-81-954649-1-3
December 2022
P a g e | 10 Volume 2, Issue 1
molecules on capacitive deionization of sodium
sulfate salt solution using activated carbon cloth
electrodes. Electrochim. Acta 279, 24–33.
https://doi.org/10.1016/j.electacta.2018.05.053
Tsai, S., Hackl, L., Kumar, A., Hou, C., 2021.
Exploring the electrosorption selectivity of nitrate
over chloride in capacitive deionization ( CDI ) and
membrane capacitive deionization ( MCDI ).
Desalination 497, 114764.
https://doi.org/10.1016/j.desal.2020.114764
Wang, K., Liu, Y., Ding, Z., Chen, Z., Xu, X., Wang,
M., Lu, T., Pan, L., 2022. Chloride pre-intercalated
CoFe-layered double hydroxide as chloride ion
capturing electrode for capacitive deionization.
Chem. Eng. J. 433, 133578.
https://doi.org/10.1016/j.cej.2021.133578
Wang, Yin, Du, B., Wang, J., Wang, Yun, Gu, H.,
Zhang, X., 2018. Synthesis and characterization of a
high capacity ionic modified hydrogel adsorbent and
its application in the removal of Cr(VI) from aqueous
solution. J. Environ. Chem. Eng. 6, 6881–6890.
https://doi.org/10.1016/ j.jece.2018.10.048
Wu, H., Chen, R., Du, H., Zhang, J., Shi, L., Qin, Y.,
Yue, L., Wang, J., 2019. Synthesis of activated
carbon from peanut shell as dye adsorbents for
wastewater treatment. Adsorpt. Sci. Technol. 37, 34–
48. https://doi.org/10.1177/0263617418807856
Xiao, Y., Zhang, W., Jiao, Y., Xu, Y., Lin, H., 2021.
Metal-phenolic network as precursor for fabrication
of metal-organic framework (MOF) nanofiltration
membrane for efficient desalination. J. Memb. Sci.
624, 119101.
https://doi.org/10.1016/j.memsci.2021.119101
Xie, Z., Shang, X., Yan, J., Hussain, T., Nie, P., Liu,
J., 2018a. Biomass-derived porous carbon anode for
high-performance capacitive deionization.
Electrochim. Acta 290, 666–675.
https://doi.org/10.1016/ j.electacta.2018.09.104
Xie, Z., Shang, X., Yan, J., Hussain, T., Nie, P., Liu,
J., 2018b. Biomass-derived porous carbon anode for
high-performance capacitive deionization.
Electrochim. Acta 290, 666–675.
https://doi.org/10.1016/j.electacta.2018.09.104
Xing, W., Liang, J., Tang, W., Luo, Y., Tang, N.,
Huang, M., He, D., Yan, M., Wang, X., 2020.
Versatile applications of capacitive deionization (
CDI ) -based technologies 482.
https://doi.org/10.1016/j.desal.2020.114390
Zhang, X., Yang, Y., Lv, X., Wang, Y., Liu, N.,
Chen, D., Cui, L., 2019. Adsorption/desorption
kinetics and breakthrough of gaseous toluene for
modified microporous-mesoporous UiO-66 metal
organic framework. J. Hazard. Mater. 366, 140–150.
https://doi.org/10.1016/j.jhazmat.2018.11.099
Zhang, Y., Ghyselbrecht, K., Meesschaert, B., Pinoy,
L., Van der Bruggen, B., 2011. Electrodialysis on
RO concentrate to improve water recovery in
wastewater reclamation. J. Memb. Sci. 378, 101–
110. https://doi.org/10.1016/j.memsci.2010.10.036
Zhang, Z., Li, H., 2022. Reconfiguring the interface
charge of Co@Carbon polyhedron for enhanced
capacitive deionization. Chem. Eng. J. 447, 137438.
https://doi.org/10.1016/j.cej.2022.137438
