12 5 ESPR-S-15-05957

Environmental Science and Pollution Research
Efficient removal of lead (II) and methylene blue from aqueous solution using ecofriendly Rosmarinus officinalis waste: Kinetic, isotherm and thermodynamic studies.
--Manuscript Draft-Manuscript Number:
Full Title:
Efficient removal of lead (II) and methylene blue from aqueous solution using ecofriendly Rosmarinus officinalis waste: Kinetic, isotherm and thermodynamic studies.
Article Type:
Research Article
Keywords:
Eco-friendly biosorbent,
methylene blue,
lead (II),
Rosmarinus officinalis,
Waste materials valorization,
thermodynamics parameters.
Corresponding Author:
Amel CHAABOUNI, Doctor
Faculté des Sciences de Sfax
Cité Elhabib Rue de Soukra Km3, Sfax TUNISIA
Corresponding Author Secondary
Information:
Corresponding Author's Institution:
Faculté des Sciences de Sfax
Corresponding Author's Secondary
Institution:
First Author:
Zied MARZOUGUI, Ph.D
First Author Secondary Information:
Order of Authors:
Zied MARZOUGUI, Ph.D
Amel CHAABOUNI, Doctor
Boubaker ELLEUCH, Professer
Order of Authors Secondary Information:
Funding Information:
Abstract:
The biosorption of lead (II) ions and methylene blue from aqueous solution using an
eco-friendly adsorbent ROBW (e.g., Rosmarinus officinalis biowaste obtained as byproduct from locally extraction industries of essential oils) has been considered in this
work. The biosorption experiments were carried out batch wise where the influence of
physicochemical key parameters such as initial pH solution, contact time, initial
adsorbate concentration, the amount of biosorbent, temperature and biosorbent
particle size were evaluated. The results of the study indicated that with the increased
adsorbent doses the adsorption capacity values decreased while the removal
percentage of adsorbate increased, whereas, no influence of particles size was
evidenced. The maximum biosorption occurred at pH 8.0 and 5.0, for methylene blue
and lead (II) ions respectively. The biosorption kinetic data were properly fitted with the
pseudo-second-order kinetic model. The equilibrium data fitted very well to the
Langmuir model with a maximum monolayer biosorption capacity of 52.63 and 43.47
mg/g, for methylene blue and lead (II) ions respectively. Thermodynamic parameters
such as Gibbs free energy, enthalpy and entropy were determined. Our study suggests
that ROBW can be used as cost-effective and efficient adsorbents for the removal of
heavy metals and cationic dyes from contaminated waters.
Suggested Reviewers:
Raja Ben Ammar , Professer
University of Sfax
[email protected]
I suggest Pr. Ben Ammar as reviewer because she is an expert in their field;
environemental process and wastewater treatment
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation
Nesrine BOUJELBENE, Dr
University of Sfax
[email protected]
I suggest Dr Boujilben because she is an expert in her Environmental Chemistry,
Green Chemistry, and Analytical Chemistry
Ragab Ragab, Professer
center for ecology and hydrology
[email protected]
I suggest Pr Ragab as reviewer because he is an expert in her Environmental impact
assesment, Environmental science and water ressources
Opposed Reviewers:
Additional Information:
Question
Response
Are you submitting to a Special Issue?
No
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation
Manuscript
Click here to download Manuscript Manuscrit ROBW_ 29_10_2015..docx
Click here to view linked References
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Efficient removal of lead (II) and methylene blue from aqueous solution
using eco-friendly Rosmarinus officinalis waste: Kinetic, isotherm and
thermodynamic studies.
Zied MARZOUGUI, Amel CHAABOUNI, Boubaker ELLEUCH
Laboratory Water-Environments and Energy (3E), National School of Engineers of Sfax
B.P. 1173, 3038, Sfax-Tunisia.
Correspondence to: Amel Chaabouni: [email protected]
1
Abstract
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
The biosorption of lead (II) ions and methylene blue from aqueous solution using an ecofriendly adsorbent ROBW (e.g., Rosmarinus officinalis biowaste obtained as by-product from
locally extraction industries of essential oils) has been considered in this work. The
biosorption experiments were carried out batch wise where the influence of physicochemical
key parameters such as initial pH solution, contact time, initial adsorbate concentration, the
amount of biosorbent, temperature and biosorbent particle size were evaluated. The results of
the study indicated that with the increased adsorbent doses the adsorption capacity values
decreased while the removal percentage of adsorbate increased, whereas, no influence of
particles size was evidenced. The maximum biosorption occurred at pH 8.0 and 5.0, for
methylene blue and lead (II) ions respectively. The biosorption kinetic data were properly
fitted with the pseudo-second-order kinetic model. The equilibrium data fitted very well to the
Langmuir model with a maximum monolayer biosorption capacity of 52.63 and 43.47 mg/g,
for methylene blue and lead (II) ions respectively. Thermodynamic parameters such as Gibbs
free energy, enthalpy and entropy were determined. Our study suggests that ROBW can be
used as cost-effective and efficient adsorbents for the removal of heavy metals and cationic
dyes from contaminated waters.
Key words:
Eco-friendly biosorbent, methylene blue, lead (II), Rosmarinus officinalis, Waste materials
valorization, and thermodynamics parameters.
2
1. Introduction
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Rapid industrialization and urbanization have resulted in the generation of large quantities
of aqueous effluents, many of which contain high levels of toxic pollutants such as dyes and
heavy metals; Dyes are widely used in many industries like textile, leather, cosmetics, paper
printing, plastic, pharmaceuticals, food, etc… to color their products. Dyes can be toxic to the
aquatic life in receiving waters, being some of them mutagenic and carcinogenic. Most of the
manufacturers always go for the most stable dyes making them highly persistent in the
environment (I.A. Aguayo-Villarreal et al. 2013; I.D. Mall et al. 2006). In addition, the
degradation by-products of some synthetic organic dyes represent a potential environmental
hazard since they contain aromatic amine compounds that are toxic to many organisms
(Jenifer et al. 2014). Particularly, textile industries usually discharge huge amount of
wastewater mainly containing synthetic dyes. In a typical dyeing and finishing mill, about 100
liters of water is consumed on an average for every ton of clothes processed (Md. Motiar et al.
2011). On the other hand, metal processing and metal working industry, particularly
electroplating and surface finishing, is an important sector producing enormous amounts of
wastewaters containing mainly heavy metals ions (Bozic et al. 2009). The major concern with
heavy metals is their ability to accumulate in living organisms, causing severe disorders and
diseases. Detrimental effects on ecosystems and the health hazards associated with dyes and
heavy metals have been established beyond any doubt, making it absolutely necessary to be
removed (Marina et al 2014). Various treatment procedures have been developed for the
removal of these contaminants from industrial effluents such as ion exchange, reduction,
chemical precipitation and coagulation, membrane separation, osmosis and reverse osmosis,
and electrolytic technologies (Saliha et al. 2007; Yuying et al. 2015). However, the necessity
of using expensive chemicals in some methods as well as accompanying disposal problem are
among the drawbacks of these conventional methods (Yuying et al. 2015) and therefore limit
their wide scale application (Muhammad et al. 2009). As a result of these short comings,
adsorption is considered as an efficient and economical method that can be used for the
removal of toxic pollutants from effluents and industrial wastewaters with high retention
efficacy when applied with the proper adsorbent (Jenifer et al. 2014), especially if the
adsorbent is inexpensive and readily available. Indeed the cost of used adsorbents is the most
important restricted factor in view of applicability of the adsorption process (A. Ozer. 2007).
Currently activated carbon is the most widely used adsorbent for dyes and metal ions removal
but due to its expensive production and regeneration, it is still considered uneconomical.
3
Therefore, there is a growing need to find up low-cost, locally available, and effective
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
adsorbent for contaminants treatments (Vesna et al. 2014). This difficulty can be overcome by
using raw biomass wastes generated in agriculture and forestry industries. The native
exchange capacity and general biosorption characteristics of these biological materials derive
from their components: cellulose, hemicelluloses, pectin, lignin, and proteins; which are biopolymeric materials containing a variety of functional groups that can adsorb certain
contaminants in water (Litza et al. 2013). The advantage of using agricultural and forestry
solid wastes as adsorbents is that it saves disposal costs while alleviating potential
environmental problems (Chun-Shui et al. 2009). Therefore, in recent years, extensive
research has been undertaken to investigate the application of a number of natural resources
including agro-industrial waste as efficient, locally available and low-cost biosorbent to
remove several contaminants from water and wastewater.
Recent studies have shown that various types of biomasses, Viscum album L (Saliha et al.
2007), coir pith (Md. Motiar et al. 2011), deciduous trees sawdust (D. Bozic et al. 2009),
Mango peel waste (Muhammad et al. 2009), agave bagasse (Litza et al. 2013), sugar extracted
spent rice biomass (Muhammad et al. 2012), dried cactus cladodes (Noureddine et al. 2013),
pine bark (Ali et al. 2009), etc. have the potential to be efficient and cost-effective biosorbent.
In continuation of these efforts, the waste biomass of Rosemary (Rosmarinus Officinalis)
was evaluated to determine its potential as metals and dyes biosorbent. Rosemary is a woody
shrub with a pine needle like leaves. Its trusses of blue flowers last through spring and
summer, R. officinalis is growing wild in bioclimatic zones in Tunisia; e.g., 38 thousand tons
are generated annually in Tunisia (The Tunisian Ministry of Agriculture, Water and Fisheries
Resources). High quantities of Rosemary’s biomass are used in several local distilleries for
the extraction of essential oil by hydro-distillation. After extraction of the oil, the remained
biomass of Rosemary, is considered to be a waste and is discharged or incinerated, becoming
a problem for environmental protection. Therefore, an advantageous waste management
process for that remained biomass is by utilizing them as a biosorbent for purifying effluents.
At present, there is no information about using Rosemary’s waste biomass as a biosorbent
earlier.
In this study, Rosemary’s waste biomass obtained at no-cost from a local distillery in
Kasserine-Tunisia, was evaluate as a new, inexpensive and environment-friendly adsorbent
material (ROBW) for treating aqueous solution containing toxic metals and dyes. Lead ions
(Pb2+) and methylene blue (MB) were selected as representatives of heavy metal and dye,
respectively. The study includes an evaluation of the effects of various process parameters
4
such as, the pH solution, adsorbent concentration, contact time, contaminants concentration
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
and temperature. The kinetics, isotherms and thermodynamics of MB and Pb(II) adsorption
onto ROBW were also evaluated..
2. Materials and methods
2.1. Biosorbent preparation
Rosmarinus officinalis biowaste (ROBW) after the extraction of the essential oil was
collected from a local distillery in Kasserine-Tunisia, the biowaste was thoroughly washed
with tap water, then washed twice with distilled water to remove dirt particles. Afterward
samples were cut into small pieces and were oven dried at 70°C for 24 h, then ground and
sieved to a particle size of 63- 500 µm. The adsorbent thus obtained ROBW was stored in a
glass bottle for future use without further treatment.
2.2. Adsorbates preparation
Methylene blue (MB), used as a cationic dye model for this experiment, was purchased
from Sigma Aldrich and used without further purification. A stock solution (1000 ppm) of
MB dye was prepared by dissolving 1.0 g of MB in 1 L of distilled water. The experimental
solutions of desired concentration were prepared by diluting the stock solution with distilled
water. The concentration of MB dye was measured at λmax= 665 nm using UV–visible
spectrophotometer (Spectro UV-VIS Double PC UVD-2950 LABOMED, INC).
Lead ions Pb(II) which is one of the most toxic heavy metal for human was used as a
cationic heavy metal model for this study. Pb(NO3)2 was purchased from Sigma Aldrich. A
stock solutions (1000 ppm) of Pb(II) ions was prepared by dissolving appropriate amount of
Pb(NO3)2 in distilled water. The experimental solutions of desired concentration were
prepared by diluting the stock solution with distilled water. The initial and final metal
concentrations were determined by atomic absorption technique using flame atomic
absorption Thermo Scientific, model ICE 3000 AA Spectrophotometer. The desired pH value
of solution was adjusted by adding either 0.1 M HCl (0.1 M) or NaOH (0.1 M) solution and
was measured using a WTW in Lab pH-720 Meter.
2.3. Biosorbent characterization
2.3.1. Point of zero charge
The point of zero charge (pHPZC) of the ROBW, which corresponds to the point of balance
between positive and negative charges on the material surface, was determined by the solid
5
addition methods (V. Ponnusami et al. 2008; Muhammad et al. 2009; Dahu et al. 2013; Vesna
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
et al. 2014). To a series of 100 mL stoppered flask, 50 ml of NaCl (0.1 M) solution was
transferred. The initial pH (pHi) values of the solutions were roughly adjusted from 2 to12 by
adding either 0.1 HCl or NaOH. The pHi values of the solutions were then accurately noted,
and 0.2 g of ROBW was added to each flask, which were securely capped immediately. The
suspensions were then shaken at 250 rpm using an orbital shaker, allowed to equilibrate for 7
hours and the pH values of the supernatant (pHf) were measured. The difference between the
initial and final pH value, (ΔpH= pHi - pHf ) was plotted against the pHi and the point of
intersection of the resulting curve at which ΔpH=zero gave the pHPZC.
2.3.2. FTIR and SEM analysis
FTIR spectroscopy (PerkinElmer Spectrum Version 10.00.00) was done to identify the
chemical functional groups present on ROBW. IR absorbance data were obtained in wave
numbers in the ranging from 4000 to 400 cm−1. The surface morphology of the ROBW was
performed with scanning electron microscopy QUANTA 200 (FEI), operating at an
acceleration voltage of 20 kV. The granules were mounted on circular aluminum stubs with
double sided adhesive tape and coated with gold for test.
2.4. Batch adsorption experiments
The ability of ROBW to adsorb MB and Pb(II) was tested at different conditions (see
Table 1) using a series of batch tests in a shaker-incubator instrument (OI®SI50). For each
test, 25 mL of the adsorbate solution with the desired composition was poured into a 50 mL
stoppered flask, a given amount of ROBW was added, the temperature of the incubator was
adjusted to the desired level, and the instrument was used to stir the mixture at 200 rpm for a
preset time. As soon as the mixing time was completed, the mixtures were centrifuged and the
clear supernatant liquids were analyzed for the residual Pb2+ concentrations by using atomic
absorption spectrophotometer, and for the residual MB concentrations by using UV–visible
spectrophotometer.
The adsorption capacity (qe) and removal efficiency (R %), were calculated according to
the following equations (1) and (2), respectively:
Ci − Cf
V
W
Ci − Cf
R% = (
) x 100
Ci
qe =
6
(1)
(2)
Where Ci and Cf (mg/L) are the initial and final adsorbate concentrations in solution,
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
respectively, V (L) is the volume solution and W (g) is the used adsorbent mass. For timedependent data, Ct replaces Ceq and qt replaces qe in Eq (1).
The effect of the experimental operational parameters such as the initial pH, the adsorbate
concentration, the ROBW dose, the ROBW particles size, the contact time, and the
temperature on MB and Pb (II) removal was analyzed by plotting either qe or R% versus the
investigated variable. After finding the optimum conditions for the tested variables, the
kinetics, equilibrium, and thermodynamics parameters of MB and Pb (II) adsorption onto
ROBW were determined and evaluated.
3. Results and discussion
3. 1. Biosorbent characterization
3. 1.1. FT-IR of ROBW
The FTIR spectrum of ROWB is shown in Fig. 1. The spectra are complex due to
numerous different types of functional groups on the surface of adsorbent. Peaks were
assigned to various groups in accordance with their respective wave numbers (cm−1) as
reported in literature, the wide band observed at 3351 cm-1 indicates that free and
intermolecular bonded O-H groups were present, which is consistent with the peak at 1028
cm-1 and assigned to alcoholic C-O stretching vibration. The band at near 2925 cm-1 was
assigned as the stretching vibration of the C-H in -CH, -CH2 and -CH3 groups that were
present in the lignin structure. The peak observed at 1601 cm−1 is assigned to C= C ring
stretch of aromatic rings. In addition, the bands at 1508 and 1423 cm−1 confirm the presence
of C=C relating to aromatic rings. The band at 1238 cm−1 is assigned to phenolic hydroxyl
groups present in lignin. The spectrum also displays a strong band at1734 cm−1, which is
assigned to the carbonyl group stretching from ester or carboxylic acid group. The band at
1641 cm−1 is assigned to carboxylate ion groups. These FTIR bands indicate that the ROBW
presents different surface structures, e.g., aliphatic, aromatic, cyclic and different functional
groups such as, hydroxylic, phenolic and carboxylic groups (A.A. Jalil et al. 2012; María
Ángeles et al. 2010; Betina et al. 2009) that can be deprotonated thus being potential
adsorption sites for interaction with cationic dyes such as the MB and with cationic metal
such as Pb (II).
Fig. 1. FTIR Spectrum of ROBW.
7
3. 1.2. SEM analysis of ROBW
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
The surface morphology of ROWB, as visualized by SEM is depicted in Fig. 2. It was
found that ROBW belongs to a nonporous solid material with respect to its surface
smoothness. Such arrangement is similar to what was reported for rice straw; Felycia Edi et
al. 2013.
Fig. 2. SEM micrograph of Rosmarinus officinalis biowaste.
3.2. Effect of initial pH
The initial pH of metal and dye solutions has been recognized by many authors as the
major parameter controlling metal and dye adsorption processes (Biswajit et al. 2013). This is
mainly due to the fact that protons are strong competing adsorbate ions and partly due to the
chemical speciation of the metal ions and dye in solution and the fact that the pH of a solution
influences the ionization of the functional groups of the adsorbents, hence consequently sets
the surface charge of adsorbent (Lei et al. 2014; D. Bozic et al. 2009). The pHZPC plot for
ROBW is shown in Fig.3 and was determined as 5.3. This indicates that at pH lower than
pHpzc the surface of adsorbent will be positively charged, and it will be negatively charged if
the pH is made greater than the pHpzc (I.D. Mall et al. 2006; Milan et al. 2013; Dahu et al.
2013).
Fig. 3 Point of zero charge (pHpzc) curve of ROBW.
Investigation of the effects of initial pH on the adsorption of the dye is important because
industrial dye wastewater is discharged at a pH that differs from the environmental pH (A.A
Jalil et al. 2012). In this study, the effects of initial pH on MB adsorption capacity and
removal efficiency using ROBW adsorbent were evaluated, and the results were illustrated in
Fig. 4. The uptake of MB is low under conditions that are highly acidic and become higher as
the pH increases reaching a maximum at pH 8 (see Fig. 4. a), the maximum adsorption
capacity reaches (45.49 mg/g) while the maximum removal efficiency reaches (72.78 %).
Further increase in the pH shows no significant change. The H+ ions effectively competed
with the MB cations, which caused dye uptake to reduce at low pHs, when the pH increases,
competing effect of hydronium ions for binding sites on ROBW surface decreased, so the
retention is favored. Furthermore at pH higher than the pHzpc, the negative charge density at
the adsorbent surface increases hence positively charged MB uptake increases. Similar
observation was also reported in literature (Biswajit et al. 2013; V. Ponnusami et al. 2008). In
order to continue this work, the pH value for the rest of the experiments was fixed at 8, as
8
being an intermediate value of acidity of the optimized pH range.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Fig. 4 Effect of initial pH on the adsorption capacity and removal efficiency for MB (a) and
Pb(II) (b) of ROBW.
The effect of the pH on the Pb(II) biosorption onto the ROBW was evaluated, and the
results were illustrated in Fig. 4. b. It can be observed, that the biosorption of Pb(II) is highly
pH-dependent, The uptake of Pb(II) ions is low under highly acidic conditions (qe=1.82 mg/g
and R%= 8.72 %) and increases as the pH increases, the maximum adsorption capacity of
ROBW for Pb(II) reaches (19.90 mg/g) and the removal efficiency of Pb(II) reaches the
optimum value of (95.5%) at pH 5. Low adsorption capacities observed for Pb(II) ions in
high acidic medium may be due to the fact that hydrogen ion strongly compete with Pb(II) for
binding sites on the adsorbent. As solution pH increases, the hydrogen ion concentration of
the solution decreases, there by competing effect of hydronium ions for binding sites on
ROBW surface decreased, so Pb(II) uptake was increased (Augustine. 2009). Another aspect
that must be considered is the dissociation degree of functional groups from biosorbent
surface which increases as the pH increases and so does the number of negatively charged
sites, and in consequence, the number of electrostatic interactions will increase, so this
increases Pb(II) uptake (Dumitru et al. 2012). This is in accordance with the earlier
observations of Ali Gundogdu et al. 2009, and D. Božić et al. 2009. In order to continue this
work, the pH value for the rest of the experiments was fixed at 5 since experiments could not
be conducted beyond pH 6.0 to avoid precipitation of Pb(II) ions as Pb(OH)2. From an
engineering point of view, it is important to note that the stripping of adsorbed metal from the
loaded ROBW can be performed by high acidic solutions, transferring the adsorbed heavy
metals from the adsorbent back into the aqueous phase.
3.3. Effect of particle size
In order to see how adsorbent particle size affects the MB and Pb(II) uptake, a series of
experiments was performed using different particles size (63-500 µm) keeping the other
parameters constant as indicated in table 1. MB or Pb(II) uptake versus particle size adsorbent
are represented in Fig. 5.
Fig. 5. Influence of the ROBW particle size on the uptake of MB (a) and Pb(II) (b).
Fig. 5 show that there is no remarkable change on the capacity uptake when the particle
size change, so the uptake can be considered as being independent of particles size as
indicated by some authors (Noureddine et al. 2013; Yanfang et al. 2013). This phenomenon
9
can be explained by the specific shape of the particles which was flaky, as shown in the
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
optical photograph (see Fig. 6). Therefore, this geometrical surface for these particular
particles is higher than spherical particles of the same volume. Changing the particle size in
the chosen sieve fractions, particles size range from 63 to 500 µm, does not change
significantly the real surface area and the adsorption degree remains almost constant with
changing particles size. Such arrangement is similar to what was reported by D. Božić et al.
2009.
Fig. 6. Optical photograph of the Rosmarinus officinalis waste: particle size < 100 µm.
3.4. The effect of contact time and biosorption kinetics
The results of sorption studies, carried out as a function of contact time, for MB and Pb(II)
were presented in Fig. 7. The initial high rate of adsorption of metal ions is due to free active
binding sites on the surface of the adsorbent. As the number of available sites decrease the
rate of adsorption of metal ions also decreases. It suggested that the removal of MB or Pb(II)
by the ROBW adsorbent took place in two distinct steps: a relatively quick phase, followed by
a slow increase until the equilibrium was reached. The necessary time to reach the
equilibrium was about 60 min. Though there was a slight increase of adsorption quantity after
60 min, it did not bring any remarkable effect, so a contact time of 60 min was selected for all
further studies.
Fig. 7. Effect of contact time on the adsorption capacity for MB (a) and Pb(II) (b) by ROBW.
The kinetics of the ROBW-adsorbate interactions was tested with different kinetic models
including pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The
pseudo-first-order equation is among the most widely used to predict metal and dye
adsorption experiments (Gholamreza and Rasoul. 2011; Ali et al. 2009; A. Ozer. 2007;
Muhammad et al. 2009). The model has the following form:
𝑑𝑞
= 𝐾1 (𝑞𝑒 − 𝑞𝑡 )
𝑑𝑡
Where qt (mg/g) is the adsorption capacity of adsorbate adsorbed at time t, qe is adsorption
capacity of adsorbate adsorbed at equilibrium (mg/g), and k1 is the rate constant of the
adsorption (min−1). After definite integration by applying the conditions qt=0 at t=0 and qt=qt
at t=t, it turns into the following equation:
ln(q e − q t ) = lnq e − K1 t
10
Straight line in the graph (see Fig. 8) of ln (qe−qt) versus (t) can suggest the applicability of
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
this kinetic model, qe.cal and k1 are determined from the intercept and slope of the plot,
respectively and presented in table 2.
The pseudo-first-order data do not fall on straight lines. The correlation coefficient is less
than 0.88, which is indicative of a poor correlation and the theoretical qe,cal values found from
this model is not in a good agreement with the experimental qe,exp. Values. Therefore, the
pseudo-first-order model is not suitable for modeling the biosorption of MB and Pb(II) onto
ROBW.
The pseudo-second-order kinetic model is in the following form
𝑑𝑞
= 𝐾2 (𝑞𝑒 − 𝑞𝑡 )2
𝑑𝑡
Where k2 (g/mg.min) is the rate constant of the second order equation; qt (mg/g) the
adsorption capacity at time t (min), and qe (mg/g) is the adsorption capacity at equilibrium.
After definite integration by applying the conditions qt=0 at t=0 and qt=qt at t=t the equation
above turns into the following:
t
1
1
= t+
qt qe
K 2 q2e
The plot of t/qt versus (t) should give a straight line if second order kinetics is applicable,
and qe and k2 can be determined from slope and intercept of the plot, respectively (Ali et al.
2009; E.I. El-Shafey et al. 2010; I.D. Mall et al. 2006). The linear plot of t/qt versus t for the
pseudo-second-order kinetic model is shown in figure 8. The pseudo-second-order rate
constant k2 and the value of qe were determined from the model and are presented in table 2.
The value of correlation coefficient is close to 1, and the theoretical qe,cal values found from
this model is closer to the experimental one qe,exp value. In view of these results, It can be said
that the adsorption process of MB or that of Pb(II) onto ROBW follow pseudo-second order
kinetic model which implies that the chemical binding reaction is the rate-limiting step.
Several other adsorption studies using biosorbent such as B.H. Hameed et al. 2008 and Azlan
et al. 2014, showed that the adsorption process followed the pseudo-second order kinetic
model.
The kinetic rate models mentioned above could not identify the diffusion mechanism,
hence the obtained results were further analyzed by using the intraparticle diffusion model
expressed as:
𝑞𝑡 = 𝐾𝑖𝑑 𝑡1/2 + 𝐶
11
Where qt (mg/g) is the adsorption capacity at time t(min), and Kid (mg/g.min) is the rate
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
constant of intraparticle diffusion. A straight line in the graph of qt versus t½ suggests the
applicability of the intraparticle diffusion model. Kid and C can be determined from the slope
and intercept of the plot, respectively (Ali et al. 2009; Md. Motiar et al. 2011). The
intraparticle rate constant Kid and C parameters were obtained from the plot of qt versus t½
and the results are given in table 2. The correlation coefficient obtained from the model is not
satisfactory, indicating that the intraparticle diffusion model may not be the controlling factor
in determining the kinetics of the process. This is consistent with the nonporous structure
previously identified by the SEM analysis.
Fig. 8. Pseudo-first-order (1) and pseudo-second-order (2) models for the adsorption onto
ROBW.
Tab. 2. Adsorption kinetic parameters of Rosmarinus officinalis waste.
3.5. Biosorption isotherms
Adsorption isotherm describes the relationship between the amount of the adsorbate
adsorbed at equilibrium by adsorbent and the equilibrium concentration of adsorbate in the
solution, which is the most important piece of information in understanding an adsorption
process (Fei et al. 2011). They are characterized by certain constants and describe the
mathematical relationship between the quantity of adsorbate and concentration of adsorbate
remaining in the solution at equilibrium. There are several isotherm equations describing the
equilibrium and the most common of them are Langmuir, Freundlich, Temkin and DubininRadushkevish models. In the present investigation, this four adsorption models were
employed for adsorption isotherm modeling of the experimental data (A. Ozer. 2007;
Jonathan et al. 2009). Linear regression is used to determine the best-fitting isotherm and the
applicability of isotherm equations is compared by judging the correlation coefficients, R2.
Langmuir isotherm is based on two assumptions that the forces of interaction between
adsorbed molecules are negligible and once a molecule occupies a site no further sorption
takes place. The linear form of Langmuir model can be described as follows:
Ce
1
1
=
Ce +
q e q max
q max K L
Where qe (mg/g) is the absorption capacity of MB or Pb(II) adsorbed per unit weight of
ROBW, Ce (mg/L) is
equilibrium concentration of solute, qmax (mg/g) indicates the
monolayer adsorption capacity of ROBW and the Langmuir constant KL (L/mg) is a direct
measure of the intensity of adsorption and it can be calculated from the plot of Ce/qe versus
12
Ce. The feasibility of adsorption onto ROBW was further analyzed using a dimensionless
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
parameter: R L = 1+K
L Ci
where Ci (mg/L) is the initial concentration of MB or Pb(II) ions and
KL (L/mg) is the Langmuir isotherm constant. The adsorption process can be defined as
irreversible irreversible (RL = 0), favourable (0< RL <1), linear (RL =1) or unfavourable (RL
>1) (Chun-Shui et l. 2009).
Freundlich isotherm is an empirical equation based on sorption on a heterogeneous surface
or surface supporting sites of varied affinities (Jonathan et al. 2009). The linear form of
Freundlich is given by the following equation:
1
log q e = logK F + log Ce
n
Where KF (mg/g) and 1/n (L/g) are Freundlich constants, related to adsorption capacity and
adsorption intensity, respectively. KF and 1/n can be calculated from the plot of log qe versus
log Ce.
Dubinin-Radushkevich (D–R) isotherm model were applied to determine the sorption type
(physical or chemical sorption), which is more general than the Langmuir model because it
does not require homogenous sorption sites or constant sorption potential. The linear from of
the model is described as;
𝐿𝑛 𝑞𝑒 = 𝐿𝑛 𝑞𝑚𝑎𝑥 − Bε2
ε is the Polanyi potential which is equal to:
ε = 𝑅𝑇 𝐿𝑛 (1 +
1
)
𝐶𝑒
The plot of lnqe vs. ε2 (figure not shown) should give a straight line from which the values
of B and qmax for ROBW were calculated. Using the value of B, the mean sorption energy, E
(kJ/mol), was evaluated as:
𝐸=
1
√−2𝐵
This parameter gives information about chemical or physical sorption. The magnitude of E
is between 8 and 16 kJ/mol, the process follows chemical sorption, while for the values of E <
8 kJ/mol, the process is of a physical nature (Chun-Shui et l. 2009; Augustine. 2010).
Temkin isotherms describe certain adsorbent/adsorbate interaction on adsorption
isotherms. Temkin isotherm suggested that the heat of adsorption of all the molecules in the
layer would decrease linearly with coverage because of those interactions. The Temkin model
is given by:
13
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
𝑞𝑒 =
𝑅𝑇
𝑅𝑇
. 𝐿𝑛 𝐴 +
. 𝐿𝑛 𝐶𝑒
𝑏
𝑏
Where b refers to the Temkin constant related to heat of sorption (kJ mol−1), A to the
Temkin isotherm constant (L g−1), R to the gas constant (8.3145 J mol−1 K−1), and T to the
absolute temperature (K). The A and b constants were determined from the slope and
intercepts of the plots obtained by plotting qe versus Ln Ce (figure not shown) and are listed in
Table 3.
Isotherms parameters with correlation coefficients R2 for the adsorption of MB and Pb(II)
onto ROBW were summarized in table 3. From the comparison of the R2 values, it was evident
that for the studied systems, the Langmuir model is very suitable to describe the adsorption
behavior for both MB and Pb (II) ion. Furthermore, the theoretical saturated adsorption
capacities simulated using the Langmuir model; 52.63 and 43.47 mg/g for MB and Pb2+ ions,
respectively, are very close to the experimental results. Moreover, the calculated values of RL
fall between 0 and 1, which indicate the favourable adsorption of MB and Pb2+ ions by
ROBW. The adsorbent surface is therefore said to be homogeneous in terms of surface
functional groups and bonding energy with no side interactions with the adsorbed ions and/or
molecule. It also assumes that the interactions take place by adsorption of one ions or
molecule per binding sites.
Fig. 9. Langmuir (a) and Freundlich (b) isotherm models for the adsorption of ROBW.
Tab. 3. Adsorption isotherm parameters of R. officinalis waste.
Tab. 4. Comparison of adsorption capacities of various adsorbents for MB and Pb(II) ions.
As comparison, the maximum adsorption capacities of several biomass-based sorbents for
sequestering MB and Pb(II) from water are listed in Table 4. Nonetheless, this comparison is
not precise, since the experimental conditions are different. It is apparent that the adsorption
capacity of ROBW was comparable with other adsorbents. Moreover, it is worth to emphasize
that sorbent used in this work has not been modified chemically and can still successfully
compete with other biomass-based sorbents which some of them have been processed which
would increase the adsorbent cost.
3.6. Thermodynamic parameters
The thermodynamic parameters were evaluated to investigate the nature of the adsorption
of MB and Pb2+ onto ROBW. The adsorption enthalpy (ΔH°), entropy (ΔS°) and Gibbs free
energy (ΔG°) were calculated using the following thermodynamic functions:
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
𝛥𝐻 ° 𝛥𝑆 °
+
𝑅𝑇
𝑅
𝐶𝑒 (𝑎𝑑𝑠𝑜𝑟𝑏𝑒𝑛𝑡)
𝐿𝑛 𝐾𝐶 =
𝐶𝑠 (𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛)
𝐿𝑛 𝐾𝐶 = −
ΔG° = −𝑅𝑇 𝐿𝑛 𝐾𝐶
Where Kc; is the equilibrium constant of the adsorption. Cs is the concentration of the
adsorbate on adsorbent (mg/L) and Ce is the equilibrium concentration of adsorbate (mg/L)
(A.A. Jalil et al. 2012). R is the universal gas constant (8.314 J/mol.K), T is the absolute
temperature (K). Enthalpy and entropy values of adsorbate were obtained from the plot of ln
Kc versus 1/T (see figure 10) which resulted in a straight line with a slope of (-ΔH°/R) and an
intercept of (ΔS°/R). From table 5, the overall ΔG° during the adsorption was negative for the
range of temperatures investigated, which indicate that the process is feasible and the
adsorption is spontaneous with high preference of MB and of Pb(II) for the ROBW.
Increasing temperature from 20 to 40 °C (293–313 °K) for 250 mg/L of MB and for 400 mg/L
of Pb(II), led to a more negative value of ΔG°, indicating that higher temperatures
energetically favor the feasibility and spontaneity of the biosorption process. This may be
attributed to the faster mobility of solute molecules in the solution at elevated temperatures
that enhanced their adsorptivity toward the biomass surface (Yan-Ru et al. 2013). The
positive value of ΔH° suggests that the adsorption process was endothermic (Mohd Shaiful et
al. 2013) which was also supported by the increase in adsorption capacity for ROBW with the
increase in temperature (see table 5), and that the magnitude (25.71 kJ mol-1 for the BM and
21,74 kJ mol-1 for the Pb(II), respectively) was in the heat range of physisorption (<40 kJ mol1
) (A.A. Jalil et al. 2012). This is consistent with previous work reported on the adsorption of
noxious chromium on acrylic acid grafted lignocellulosic adsorbent (Vinod Kumar et al.
2013), lead(II) on Viscum album L (Saliha and Emine. 2007), malachite green (MG) on
bivalve shell-treated Zea mays L (A.A. Jalil et al. 2012), and methylene blue on chemically
modified Ficuscarica adsorbent (Mohd Shaiful et al. 2013). The positive value of ΔS°
suggested increase randomness at the solid/solution interface during the fixation of the
adsorbate on the active sites of the adsorbent which indicates that the affinity of ROBW
toward the considered adsorbent was high. This was due to the fact that before the adsorption
process starts, the adsorbate ions in solution are heavily solvated and the system becomes
more ordered. The adsorbed water molecules, which are displaced by the adsorbate species,
gain more translational energy than when is lost by the adsorbate ions, thus allowing the
prevalence of randomness in the system (Bulut and Tez. 2007).
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Fig. 10. Plot of ln KC versus 1/T for the adsorption of MB and Pb(II) ions onto R.
officinalis waste.
Tab.5. Thermodynamic parameters for the MB and Pb(II) removal by using R. officinalis
waste.
3.7. Effect of adsorbent dosage
The amount of pollutant per unit mass of adsorbent removed from a fixed concentration
and fixed volume of polluted water is known to depend on the mass of adsorbent used
(Augustine et al. 2010). Fig.11 shows the effect of ROBW dose on MB and Pb (II)
adsorption. The results of the study indicated that with the increased adsorbent doses the
removal percentage of adsorbate increased to reach a plateau. Increasing the ROBW dose
would increase the number of available adsorption sites, thereby resulting in the increase in
removal percentage of MB or Pb(II) ions, as already reported in several papers (Augustine et
al. 2010; S. Larous et al. 2005). On the other hand, increasing the mass of ROBW in contact
with a fixed concentration and fixed volume of adsorbate solution caused a reduction in the qe
values mg/g. The negative effect on sorption capacity might be due to the binding of almost
all adsorbate to the sorbent at higher adsorbent dose and the establishment of equilibrium at
lower values of qe indicating the adsorption sites remains unsaturated (Shaik et al. 2009).
Another reason might be due to the particle interaction, such as aggregation, resulting from
high adsorbent dose. Such aggregation would lead to decrease total surface area of the
adsorbent and increase in diffusional path length (Hui et al. 2011; Sana et al. 2014)
Fig. 11. Effect of Rosmarinus officinalis biowaste amount on the removal of MB (a) and
Pb(II) (b).
3.8. Biosorption ability of ROBW for other heavy metals
Wastewaters such as industrial effluents may contain large amounts of various heavy metal
ions. Therefore, biosorption capacity of R. Officinalis was also tested for removal of the
Cd(II), Cr(III) and Cu(II) ions from aqueous solution. The metal solutions with 500 mg.L−1
initial concentrations containing 4.0 g L−1 of ROBW were treated separately at pH 4.5, 4 and
5.5, respectively. The results showed that ROBW can efficiently remove Cd(II), Cr(III) and
Cu(II) ion and it was more sensitive to Cd(II) ions than the others. The following order of
metal uptake per unit weight of ROBW was observed: Cd2+ (58.82 mg.g−1) > Pb2+ (43.47
mg.g−1) > Cr3+ (35.71 mg.g−1) > Cu2+ (26.31 mg.g−1).
4. Conclusions
The results of this study indicate that Rosmarinus officinalis biowaste obtained as by16
product from locally extraction industries of essential oils is an efficient, low-cost,
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
environmental friendly bio-adsorbent and can be successfully used to remove heavy metals
and dyes from aqueous solution. The obtained results showed that the adsorption of MB and
Pb2+ by ROBW was fast, and equilibrium was achieved in less than 60 min. The adsorption
was highly dependent on the pH of the solution and initial adsorbents concentration. The
uptake can be considered as being independent of particles size. Modeling of the biosorption
results indicated that the pseudo-second order model offers a better correlation of
experimental kinetic data and Langmuir models is a suitable option for modeling the sorption
isotherms of metal ions and dyes, giving maximum adsorption capacity of 52.63 mg/g and
43.47 mg/g at 20 °C, for MB and Pb (II) ions removal, respectively. The negative ΔG° values
indicated that the adsorption process was feasible and spontaneous, and the positive values of
ΔH° and ΔS, shows that the sorption process is endothermic in nature and there is high
affinity of the adsorbent for the sorbate. It is worth to emphasize that ROBW has not been
modified chemically and can still successfully compete with other biomass-based sorbents
which some of them have been processed which would increase the adsorbent cost.
17
Reference:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
A.A. Jalil, S. Triwahyono, M.R. Yaakob, Z.Z.A. Azmi, N. Sapawe, N.H.N. Kamarudin,
H.D. Setiabudi, N.F. Jaafar, S.M. Sidik, S.H. Adam, B.H. Hameed (2012) Utilization of
bivalve
shell-treated
Zeamays
L.
(maize)
husk
leaf
as
a
low-cost
biosorbent for enhanced adsorption of malachite green. Bioresource Technology 120: 218–
224
Ali Gundogdu, Duygu Ozdes, Celal Duran, Volkan Numan Bulut, Mustafa Soylak, Hasan Basri
Senturk (2009) Biosorption of Pb(II) ions from aqueous solution by pine bark (Pinus brutia
Ten.). Chemical Engineering Journal 153 : 62–69
A. Ozer (2007) Removal of Pb(II) ions from aqueous solutions by sulphuric acid-treated wheat
bran. Journal of Hazardous Materials 141 753–761
Augustine E. Ofomaja (2010) Equilibrium studies of copper ion adsorption onto palm kernel fibre.
Journal of Environmental Management 91: 1491-1499
Azlan Kamari, Siti Najiah Mohd Yusoff, Fadhilah Abdullah, Wiwid Pranata Putra
(2014) Biosorptive removal of Cu(II), Ni(II) and Pb(II) ions from aqueous solutions using
coconut dregs residue: Adsorption and characterization studies. Journal of Environmental
Chemical Engineering 2: 1912–1919
Betina Royer , Natali F. Cardoso , Eder C. Lima, Julio C.P. Vaghetti , Nathalia M. Simon , Tatiana
Calvete , Renato Cataluna Veses (2009) Applications of Brazilian pine-fruit shell in natural
and carbonize d forms as adsorbents to removal of methylene blue from aqueous solutions
Kinetic and equilibrium study. Journal of Hazardous Materials 164: 1213–1222
B.H. Hameed, D.K. Mahmoud, A.L. Ahmad (2008) Equilibrium modeling and kinetic studies on
the adsorption of basic dye by a low-cost adsorbent: Coconut (Cocos nucifera) bunch waste.
Journal of Hazardous Materials 158: 65–72
Biswajit Singha, Sudip Kumar Das (2013) Adsorptive removal of Cu(II) from aqueous solution
and industrial effluent using natural/agricultural wastes. Colloids and Surfaces B:
Biointerfaces 107: 97–106
Bulut Yasemin, Tez Zeki (2007) Removal of heavy metals from aqueous solution by sawdust
adsorption. Jornal of Envirnnmental Sciences 19: I60-166
Chun-Shui Zhu, Li-Ping Wang, Wen-bin Chen (2009) Removal of Cu(II) from aqueous solution
by agricultural by-product: Peanut hull. Journal of Hazardous Materials 16 8: 739–746
Dahu Ding, Yingxin Zhao, Shengjiong Yang, Wansheng Shi, Zhenya Zhang, Zhongfang Lei,
Yingnan Yang (2013) Adsorption of cesium from aqueous solution using
agricultural residue e Walnut shell: Equilibrium, kinetic and thermodynamic modeling
studies. water research 47: 2563-2571
Dalia Khalid Mahmoud, Mohamad Amran Mohd Salleh, Wan Azlina Wan Abdul Karim,
Azni Idris, Zurina Zainal Abidin (2012) Batch adsorption of basic dye using acid treated
kenaf fibre char: Equilibrium, kinetic and thermodynamic studies. Chemical Engineering
Journal 181–182: 449–457
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
D. Bozic, V. Stankovic, M. Gorgievski, G. Bogdanovic, R. Kovacevic (2009) Adsorption of heavy
metal ions by sawdust of deciduous trees. Journal of Hazardous Materials 171 : 684–692
Dumitru Bulgariu, Laura Bulgariu (2012) Equilibrium and kinetics studies of heavy metal ions
biosorption on green algae waste biomass. Bioresource Technology 103: 489–493
Dursun Ozer, Gulbeyi Dursun, Ahmet Ozer (2007) Methylene blue adsorption from aqueous
solution by dehydrated peanut hull. Journal of Hazardous Materials 144: 171–179
E.I. El-Shafey (2010) Removal of Zn(II) and Hg(II) from aqueous solution on a carbonaceous
sorbent chemically prepared from rice husk. Journal of Hazardous Materials 175: 319–327
Fei Lian, Fang Huang, Wei Chen, Baoshan Xing, Lingyan Zhu (2011) Sorption of apolar and
polar organic contaminants by waste tire rubber and its chars in single- and bi-solute systems.
Environmental Pollution 159: 850-857
Felycia Edi Soetaredjo, Alfin Kurniawan, Ong Lu Ki, Suryadi Ismadji (2013) Incorporation of
selectivity factor in modeling binary component adsorption isotherms for heavy metalsbiomass system. Chemical Engineering Journal 219: 137–148
Gholamreza Moussavi, Rasoul Khosravi (2011) The removal of cationic dyes from aqueous
solutions by adsorption onto pistachio hull waste. Chemical engineering research and design
89: 2182–2189
Gloria Sánchez-Galván & Pedro A. Ramírez-Núñez (2014) Cationic Dye Biosorption by Salvinia
minima: Equilibrium and Kinetics. Water Air Soil Pollut 225: 2008
Hui Deng, Jianjiang Lu, Guoxue Li, Genlin Zhang, Xugen Wang (2011) Adsorption of methylene
blue on adsorbent materials produced from cotton stalk. Chemical Engineering Journal 172:
326–334
I.A. Aguayo-Villarreal, L.A. Ramírez-Montoya, V. Hernández-Montoya, A. Bonilla-Petriciolet,
M.A. Montes-Morán, E.M. Ramírez-López (2013) Sorption mechanism of anionic dyes on
pecan nut shells (Carya illinoinensis) using batch and continuous systems. Industrial Crops
and Products 48; 89–97
I.D. Mall, V.C. Srivastava, G.V.A. Kumar, I.M. Mishra (2006) Characterization and utilization of
mesoporous fertilizer plant waste carbon for adsorptive removal of dyes from aqueous
solution. Colloids and Surfaces A: Physicochem. Eng. Aspects 278 : 175–187
Jenifer Gómez-Pastora, Eugenio Bringas, Inmaculada Ortiz (2014) Recent progress and future
challenges on the use of high performance magnetic nano-adsorbents in environmental
applications. Chemical Engineering Journal 256: 187–204
Jonathan Febrianto, Aline Natasia Kosasih, Jaka Sunarso, Yi-Hsu Ju, Nani Indraswati, Suryadi
Ismadji (2009) Equilibrium and kinetic studies in adsorption of heavy metals using biosorb
ent: A summar y of recent studies. Journal of Hazardous Materials 162: 616–6 45
Lei Yu, Yong-ming Luo (2014) The adsorption mechanism of anionic and cationic dyes by
Jerusalem artichoke stalk-based mesoporous activated carbon. Journal of Environmental
Chemical Engineering 2: 220–229
19
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Litza H. Velazquez-Jimenez, Andrea Pavlick, J. Rene Rangel-Mendez (2013) Chemical
characterization of raw and treated agave bagasse and its potential as adsorbent of metal
cations from water. Industrial Crops and Products 43 : 200–206
María Ángeles Martín-Lara, Iván Leandro Rodríguez Rico, Inésdela Caridad Alomá Vicente,
Gabriel Blázquez García, Mónica Calero de Hoces (2010) Modification of the sorptive
characteristics of sugarcane bagasse for removing lead from aqueous solutions. Desalination
256: 58–63
Marina Fomina, Geoffrey Michael Gadd (2014) Biosorption: current perspectives on concept,
definition and application Bioresource Technology 160: 3–14
Masoud Giahi, Roohan Rakhshaee, Mohammad A. Bagherinia (2011) Removal of methylene blue
by tea wastages from the synthesis waste waters. Chinese Chemical Letters 22: 225–228
Md. Motiar R. Khan, Manju Ray, Arun K. Guha (2011) Mechanistic studies on the binding of
Acid Yellow 99 on coir pith. Bioresource Technology 102 2394–2399
Milan Gorgievski, Dragana Bozic, Velizar Stankovic, Nada Strbac, Snezana Serbula (2013)
Kinetics, equilibrium and mechanism of Cu2+, Ni2+ and Zn2+ ions biosorption using wheat
straw. Ecological Engineering 58: 113–122
Mohd Shaiful Sajab , Chin Hua Chia, Sarani Zakaria, Poi Sim Khiew (2013) Cationic and anionic
modifications of oil palm empty fruit bunch fibers for the removal of dyes from aqueous
solutions. Bioresource Technology 128: 571–577
Muhammad Iqbal, Asma Saeed, Saeed Iqbal Zafar (2009) FTIR spectrophotometry, kinetics and
adsorption isotherms modeling, ion exchange, and EDX analysis for understanding the
mechanism of Cd2+ and Pb2+ removal by mango peel waste. Journal of Hazardous Materials
16 4: 161–171
Muhammad Saif Ur Rehman, Ilgook Kim, Jong-In Han (2012) Adsorption of methylene blue dye
from aqueous solution by sugar extracted spent rice biomass. Carbohydrate Polymers 90:
1314–1322
Mustafa T. Yagub, Tushar Kanti Sen, M. Ang (2013) Removal of cationic dye methylene blue
(MB) from aqueous solution by ground raw and base modified pine cone powder. Environ
Earth Sci DOI 10.1007/s12665-013-2555-0
Noureddine Barka, Mohamed Abdennouri, Mohammed El Makhfouk, Samir Qourzal (2013)
Biosorption characteristics of cadmium and lead onto eco-friendly dried cactus (Opuntia ficus
indica) cladodes. Journal of Environmental Chemical Engineering 1:144–149
Saliha Erenturk , Emine Malkoc (2007) Removal of lead(II) by adsorption onto Viscum album L.:
Effect of temperature and equilibrium isotherm analyses. Applied Surface Science 253 4727–
4733
Shaik Basha, Z.V.P. Murthy, B. Jha (2009) Sorption of Hg(II) onto Carica papaya: Experimental
studies and design of batch sorber. Chemical Engineering Journal 147: 226–234
S. Larous, A.-H. Meniai, M. Bencheikh Lehocine (2005) Experimental study of the removal of
copper from aqueous solutions by adsorption using sawdust. Desalination 185: 483–490
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Sana Sadaf, Haq Nawaz Bhatti, Sana Nausheen, Misbah Amin (2014) Application of a novel
lignocellulosic biomaterial for the removal of Direct Yellow 50 dye from aqueous solution:
Batch and column study. Journal of the Taiwan Institute of Chemical Engineers
doi.org/10.1016/j.jtice.2014.10.001
Vesna M. Vucurovic, Radojka N. Razmovski, Uros D. Miljic, Vladimir S. Puskas (2014) Removal
of cationic and anionic azo dyes from aqueous solutions by adsorption on maize stem tissue.
Journal of the Taiwan Institute of Chemical Engineers 45: 1700–1708
Vinod Kumar Gupta, Deepak Pathania, Shikha Sharma, Shilpi Agarwal, Prerna Singh (2013)
Remediation of noxious chromium (VI) utilizing acrylic acid grafted lignocellulosic
adsorbent. Journal of Molecular Liquids 177: 343–352
V. Ponnusami, S. Vikram, S.N. Srivastava (2008) Guava (Psidium guajava) leaf powder: Novel
adsorbent for removal of methylene blue from aqueous solutions. Journal of Hazardous
Materials 152: 276–28
Wenxuan Zhang, Hu Yang, Lei Dong, Han Yan, Haijiang Li, Ziwen Jiang, Xiaowei Kan,
Aimin Li, Rongshi Cheng (2012) Efficient removal of both cationic and anionic dyes from
aqueous solutions using a novel amphoteric straw-based adsorbent. Carbohydrate Polymers
90: 887–893
Yanfang Feng, Dionysios D. Dionysiou, Yonghong Wu, Hui Zhou, Lihong Xue, Shiying He,
Linzhang Yang (2013) Adsorption of dyestuff from aqueous solutions through oxalic
acid-modified
swede
rape
straw:
Adsorption
process
and
disposal
methodology of depleted bioadsorbents. Bioresource Technology 138 : 191–197
Yan-Ru Zhang, Sheng-Qing Wang, Shi-Li Shen, Bao-Xiang Zhao (2013) A novel water treatment
magnetic nanomaterial for removal of anionic and cationic dyes under severe condition.
Chemical Engineering Journal 233: 258–264
Yuying Meng, Deyang Chen, Yitao Sun, Dongling Jiao, Dechang Zeng, Zhongwu Liu (2015)
Adsorption of Cu2+ ions using chitosan-modified magnetic Mn ferrite nanoparticles
synthesized by microwave-assisted hydrothermal method. Applied Surface Science 324: 745–
750
21
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 1: FTIR Spectrum of ROBW.
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 2: SEM micrograph of Rosmarinus officinalis biowaste.
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 3: Point of zero charge (pHpzc) curve of ROBW.
3.5
3
2.5
pHi - pHf
2
1.5
1
0.5
0
-0.5
0
2
4
6
-1
-1.5
pHi
8
10
12
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 4: Effect of initial pH on the adsorption capacity for MB (a) and Pb(II) (b) by ROBW.
qe (mg/g)
R%
80
100
(a) MB
80
60
R%
qe(mg/g)
60
40
40
20
20
0
0
0
2
4
6
pH
qe (mg/g)
8
10
12
R%
30
100
(b) Pb(II)
80
20
R%
qe(mg/g)
60
40
10
20
0
0
0
1
2
3
pH
4
5
6
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 5: Influence of the ROBW particle size on the adsorption of MB (a) and Pb(II) (b).
(a) MB
50
qe(mg/g)
40
30
20
10
0
63-80
80-100
100-125
125-315
315-500
Q(µm)
(b) Pb(II)
20
qe(mg/g)
15
10
5
0
X<63
63<X<100
100<X<125
Q(µm)
125<X<150
150<X315
315<X<400
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 6: Optical photograph of the Rosmarinus officinalis waste: particle size < 100 µm.
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 7: Effect of contact time on the adsorption capacity for MB (a) and Pb(II) (b) by ROBW.
50
(a) MB
40
qt(mg/g)
30
20
10
0
0
60
120
180
240
300
360
420
480
t(min)
25
(b) Pb(II)
20
qt(mg/g)
15
10
5
0
0
60
120
180
t(min)
240
300
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 8: pseudo-first-order (1) and pseudo-second-order (2) models for the adsorption of ROBW.
12
14
(1) MB
10
10
8
8
t/qt
t/qt
(1) Pb(II)
12
6
6
4
4
2
2
0
0
0
100
200
300
400
500
0
600
50
100
t (min)
150
200
250
300
t(min)
2
5
(2) MB
4
Ln (qe-qt)
Ln (qe-qt)
(2) Pb(II)
3
2
1
1
0
0
0
100
200
300
t (min)
400
500
600
0
200
400
600
t (min)
800
1000
1200
1400
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 9: Langmuir (a) and Freundlich (b) isotherm models for the adsorption of ROBW.
7
14
(a) MB
(a) Pb(II)
12
5
10
4
8
Ce/qe
Ce/qe
6
3
6
2
4
1
2
0
0
0
100
200
300
0
400
100
Ce (mg/L)
200
300
400
500
600
0.15
0.2
0.25
Ce (mg/L)
3
3
(b) MB
2.5
2.5
(b) Pb(II)
2
2
log qe
log qe
1.5
1
1.5
1
0.5
0
0
0.5
1
1.5
0.5
2
-0.5
0
-1
-0.05
log Ce
0
0.05
0.1
log Ce
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 10: Plot of ln KC versus 1/T for the adsorption of (a) MB and (b) Pb(II) ions onto R.
officinalis waste.
1.80
1.60
1.40
(a) MB
1.20
Ln Kc
1.00
0.80
0.60
0.40
0.20
0.00
0.00315
0.00320
0.00325
0.00330
0.00335
0.00340
0.00345
0.00335
0.00340
0.00345
1/T
0.80
0.70
(b) Pb(II)
0.60
Ln Kc
0.50
0.40
0.30
0.20
0.10
0.00
0.00315
0.00320
0.00325
0.00330
1/T
Figure
Correspondence to: Amel Chaabouni: [email protected]
Figure 11: Effect of Rosmarinus officinalis biowaste amount on the removal of MB (a) and Pb(II) (b).
R%
100
80
80
60
60
40
40
20
20
0
0
qe (mg/g)
100
0
300
5
10
CW (g/L)
qe (mg/g)
(b) Pb (II)
15
R%
qe (mg/g)
(a) MB
20
R%
100
90
250
80
70
60
150
50
40
100
30
20
50
10
0
0
0
1
2
3
4
CW (g/L)
5
6
7
8
9
R%
qe(mg/g)
200
Table
Nomenclature:
Nomenclature
A
Temkin isotherm constant (L/g)
b
Temkin sorption energy (Kj/mol)
Ci
initial MB / Pb(II) concentrations (mg/L)
Ct
MB / Pb(II) concentrations at time t of reaction (mg/L)
Ce
MB / Pb(II) concentrations at equilibrium time (mg/L)
E
D-R sorption energy (kJ/mol)
kid
constant of intraparticle diffusion (mg/(gmin0.5))
k1
pseudo-first order rate constant (1/min)
k2
pseudo-second order rate constant (mg/g.min)
kid
intraparticle diffusion the rate constant (mg/g.min)
kL
Langmuir constant (L/mg)
KDR
D–R constant (mol2/kJ2)
KF
Freundlich constant (L/mg)
Kc=Cs/Ce
the thermodynamic equilibrium constant
n
Freundlich reciprocal of reaction order
qt
adsorption capacity at time t (mg/g)
qe
adsorption capacity at equilibrium conditions (mg/g)
qmax
maximum adsorption capacity (mg/g)
R2
correlation coefficient
R%
removal efficiency
R
gas constant (8.314 J/(mol.K))
T
absolute temperature (°C) or (K)
V
volume of the MB solution (L)
W
mass of ROBW added to the solution (g)
ε
Polanyi potential (J/mol)
ΔG°
changes of Gibbs free energy
Table
Correspondence to: Amel Chaabouni: [email protected]
Table 1: Experimental runs and conditions.
Experiment
Conditions
pHi
WROBW (g/L)
Ø µm
t (min)
[MB] (mg/L)
[Pb2+] (mg/L)
2-10
4
100-125
120
250
***
20
Effect of ROBW dose
8
1-16
100-125
120
250
***
20
Effect of particle size
8
4
63-500
120
250
***
20
Effect of contact time
8
4
100-125
10-480
250
***
20
Effect of MB concentration
8
4
100-125
60
10-500
***
20
Effect of temperature
8
4
100-125
60
10-500
***
20-40
2-5
4
100-125
240
***
100
20
Effect of ROBW dose
5
0.04-40
100-125
240
***
100
20
Effect of particle size
5
4
63-400
240
***
100
20
Effect of contact time
5
4
100-125
10-240
***
100
20
Effect of Pb(II) concentration
5
4
100-125
30
***
50-800
20
Effect of temperature
5
4
100-125
30
***
50-800
20-40
Effect of initial pH
Effect of initial pH
T (°C)
Table
Correspondence to: Amel Chaabouni: [email protected]
Table 2: Adsorption kinetic parameters of Rosmarinus officinalis waste.
Adsorbate
qeq,exp (mg/g)
Pseudo-first-order
Intraparticle
Pseudo-second-order
Diffusion
k1 (min−1)
qeq,cal (mg/g)
R2
k2 (g/mg.min)
qeq,cal (mg/g)
R2
Kid
R2
MB
43.95
0.005
17.09
0.715
0.0016
45.45
0.997
0.202
0.691
Pb(II)
20.19
0.0008
05.72
0.884
0.0159
20.40
1.000
0.027
0.827
Table
Correspondence to: Amel Chaabouni: [email protected]
Table 3. Adsorption isotherm parameters of R. officinalis waste.
Langmuir
Freundlich
R-D
Temkin
Adsorbate
qmax(mg/g) KL (L/mg) RL range
R2
n
KF (L/mg)
R2
qmax DR E (KJ/mol)
R2
b (KJ/mol) A (L/g)
R2
MB
52.63
0.14
0.014-0.41
0.998
0.58
0.80
0.738
27.22
1.11
0.759
0.312
3.19
0.891
Pb(II)
43.47
0.053
0.030-0.27
0.979
0.43
0.43
0.721
33.75
0.50
0.883
0.435
3.39
0.933
Table
Correspondence to: Amel Chaabouni: [email protected]
Table 4. Comparison of adsorption capacities of various adsorbents for MB and Pb(II) ions.
Methylene blue dye (MB)
Biosorbent
Sugar spent rice biomass**
Brazilian pine-fruit shell
Brazilian pine-fruit shell**
Pistachio hull
Jerusalem artichoke stalk**
Kenaf fibre char
peanut hull**
Wheat straw **
Maize stem **
Raw pine cone
teawastages
SalviniaMinima biowaste
coconutbunchwaste
R. officinalis biowaste
Lead Pb (II)
Solute
coconut dregsresidue
Sawdust of walnut
Pine bark
wheat bran**
Sugarcane bagasse
Sugarcane bagasse **
Mango peel waste
Dried cactus
Green algae waste biomass
R. officinalis biowaste
Operational
condition
T
pH*
(°C)
--
25
8.5
25
8
3.7
8.5
3.5
10
6
9.2
8
8
7
8
20
20
30
25
20
25
30
25
25
30
20
7
-4
6
-25
-25
5
25
5
3.5
5
5
25
25
20
20
Adsorption
capacity
(mg/g)
8.3
185
413
389
363.6
18.18
108.6
132.2
160.84
129.87
173.36
174.75
74.82
52.63
9.74
15.90
76.8
55.56
6.366
7.297
96.32
98.62
66.24
43.47
Note: ∗ pH value corresponds to maximum adsorption capacity.
** The biowaste has undergone a phisico-chemical modification before being used as an adsorbent
Ref.
Muhammad et al. 2012
Betina et al. 2009
Gholamreza et al. 2011
Lei and Yong-ming. 2014
Dalia et al 2012
Dursun et al. 2007
Wenxuan et al. 2012
Vesna et al. 2014
Mustafa et al. 2013
Masoud et al. 2011
Gloria et al. 2014
B.H. Hameed et al. 2008
This study
Azlan et al. 2014
Bulut and Tez. 2007
Ali et al. 2009
A. Ozer. 2007
María Ángeles et al. 2010
Muhammad et al. 2009
Noureddine et al. 2013
Dumitru et al. 2012
This study
Table
Correspondence to: Amel Chaabouni: [email protected]
T°K
qeq (mg.g-1)
KC
ΔG° (Kj.mol-1)
ΔH° (Kj.mol-1)
ΔS° (j.mol-1K-1)
MB
293
303
313
45.26
49.32
52.34
2.63
3.74
5.15
-2.39
-3.26
-4.06
25.71
95.77
Pb(II)
Table 5. Thermodynamic parameters for the MB and Pb(II) removal by using R. officinalis
waste.
293
303
313
34.96
43.27
48.43
1.17
1.65
2.06
-0.38
-1.25
-1.88
21.74
75.59
Cover Letter
Click here to access/download
Supplementary Material
Cover letter.docx