REMOVAL OF POLLUTANTS USING RADIAL AND VERTICAL FLOW REGIME REACTORS

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International Journal of Civil Engineering and Technology (IJCIET)
Volume 7, Issue 1, Jan-Feb 2016, pp. 01-14, Article ID: IJCIET_07_01_001
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© IAEME Publication
REMOVAL OF POLLUTANTS USING
RADIAL AND VERTICAL FLOW REGIME
REACTORS
Prof. Dr. Mohammad A. M. AL- Tufaily
Faculty of Engineering, University of Babylon, Environmental Department, Iraq
Zaman Saleh Redah Al-Qadi
MSc. Student, Faculty of Engineering,
University of Babylon Environmental Department, Iraq
ABSTRACT
Batch and continuous processes were conducted to study the adsorption of
methylene blue dye on to three adsorbent materials, commercial activated
carbon, chemically activated corncob carbon with phosphoric acid and ion
exchange resin (akualite). Batch processes were established to show the
effects of solution pH, contact time, adsorbent dosage, agitation speed and
initial dye concentration. Two isotherm models, Freundlich and Langmuir
fitted with the experimental data found from batch processes, the Langmuir
model fitted well than the Freundlich, with maximum adsorption capacities of
16.21, 30.95 and 77.52 mg/g and R2
of 0.952, 0.992 and 0.995 predicted by
commercial activated carbon, corncob activated carbon akualite respectively.
Series of column test for the three adsorbent materials at different three flow
rates (0.2, 0.3 and 0.4 L/min) and three initial dye concentrations (15, 30 and
50 mg/l), the same volume of (775 ml) from adsorbent materials used for both
radial and vertical reactors to make a comparison between the capacity of the
adsorbent materials each with another and between the performance of radial
and vertical flow regime reactors configurations on breakthrough curves
behavior. Radial flow regime reactor showed good results in comparison with
vertical flow regime reactor.
Cite this Article: Prof. Dr. Mohammad A. M. AL- Tufaily and Zaman Saleh
Redah Al-Qadi. Removal of Pollutants Using Radial and Vertical Flow
Regime Reactors, International Journal of Civil Engineering and Technology,
7(1), 2016, pp. 01-14.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=1

Prof. Dr. Mohammad A. M. AL- Tufaily and Zaman Saleh Redah Al-Qadi
1. INTRODUCTION
Pollution caused by industrial wastewaters has become a common problem for many
countries. Dyes and pigments are one of the problematic groups of pollutants.
Wastewaters discharged from different industries such as the textile, leather tanning,
paper production, food technology, hair colorings, etc. are usually polluted by dyes
(Hameed and El-Khaiary, 2008). It is estimated that more than 100,000
commercially available dyes with over 7×105
tons of dyestuff produced annually.
Major problems associated with colored effluent are lowering light penetration,
photosynthesis and damages the aesthetic nature of the water surface (Mohammed et
al., 2014).
Dyes usually have complex aromatic molecular structures which make them more
stable and difficult to biodegrade. Moreover, direct discharges of synthetic dyes into
urban wastewaters in natural environments may cause the formation of toxic
carcinogenic breakdown products.
The presence of small amount of dyes (less than 1ppm) is highly visible and
undesirable (Zainol, 2010). Methylene blue (MB) is an important basic dye widely
used for coloring paper, temporary hair colorant, coating for paper stock, dyeing,
printing cotton and tannin, dyeing leather, used as an antiseptic and for other
medicinal purposes (Idris et al., 2012). MB can cause eye burns, and if swallowed, it
causes irritation to the gastrointestinal tract with symptoms of nausea, vomiting and
diarrhea. It may also cause methemoglobinemia, cyanosis, convulsions and dyspnea if
inhaled. There for, the removal of such dyes from effluents prior to their final
discharge is of significant environmental, technical, and commercial (Yan and
Wang, 2013). Treatment of dye-based effluents is considered to be one of the
challenging tasks in environmental fraternity (Himakshi et al., 2013). There are many
removal techniques such as chemical oxidation, precipitation, filtration, aerobic and
anaerobic microbial degradation, coagulation, membrane separation, electrochemical
treatment, flotation, hydrogen peroxide catalysis, and reverse osmosis, ozonation and
biological techniques can be employed to remove various pollutant form the textile
industry wastewater (Gonawala and Mehta, 2014).
However, some of these methods are non-economical and have many
disadvantages such as high reagent and energy requirements, generation of toxic
sludge or other waste products that require disposal or treatment. Among several
chemical and physical treatment methods, the adsorption has been found to be
superior to other techniques for the removal of dyes from aqueous solution in terms of
methodology, operational conditions and efficiency (Fungaro et al., 2010). Activated
carbon is widely used as an adsorbent due to its high adsorption abilities in removal of
organic pollutants from wastewater (Olivella et al., 2012). The use of carbon as an
adsorbent is limited because of its high cost. At present, there is a growing interest in
using low cost adsorbents for dye adsorption. If an adsorbent is inexpensive and ready
for use, the adsorption process will be a promising technique (Gong et al., 2008). The
abundance and availability of agricultural by products make them good sources of raw
materials for activated carbon (Taha et al., 2014). Corn is a significant crop which
can be found all around the world. The annual production worldwide is about 520×109
kg. Corncob as a biomass and agricultural waste is an attractive candidate. Usage of
these biomass wastes as a raw material for production of activated carbon is a highly
beneficial (Wang et al., 2010). Adsorption of dye using ion exchange resins is a
practical method for the removal of dyes from wastewaters and recycling water when
compared with the widely used adsorption onto activated carbon. Its main advantages

Removal of Pollutants Using Radial and Vertical Flow Regime Reactors
are as follows: the ion exchangers are not lost during the regeneration, recovery of the
process water, and the removal of soluble dye (Kauspediene et al., 2013).
In designing new internal arrangements to achieve a radial flow it is imperative
that the flow distribution obtained in the radial inward flow direction is as near ideal
as possible. This is harder than for a classic axial flow reactor because of the
increased problems of inlet flow distribution and also because of the inherently lower
pressure drops through the bed. The advantages of radial over axial flow reactors are
the high flow capacity, low pressure drop, and the possibility of using finely divided
catalysts (Li and Zhu, 2011). The packed column of radial flow chromatography
(RFC) consists of two concentric porous cylindrical sieves, between which the
stationary phase is filled with an adsorbent (Dia et al., 2009).
2. EXPERIMENTAL WORK
2.1. Adsorbate
Methylene Blue (MB) dye was used as an adsorbate in the present study. The choice
of MB dye as an adsorbate is due to its known strong adsorption on to solids. The MB
dye used was by supplied by Sigma-Aldrich, scientific bureaus in Iraq, Bagdad. A
stock solution of methylene with 1000 mg/l concentration was prepared by dissolving
1 gm of powder in 1 L of distilled water, other required concentrations were prepared
by diluting.
2.2 Adsorbents
2.2.1. Commercial Activated Carbon
Granular activated carbon supplied by Iraqi markets with effective size of 1mm was
used as an adsorbent material. Sieve analysis obtained using British standards in Kufa
University, civil engineering laboratory. Carbon was washed with distillated water for
several times to remove all impurities and then dried in electric oven for two hours at
110o
C to exclude any moisture content.
2.2.2. Corncob Activated Carbon
Corncob activated carbon was prepared as following (Rocha et al., 2015)
 Collection of the corncobs from Babylon Governorate.
 Cutting and sieving of collected corncobs to size near to 1 mm
 Washing and drying of sieved corncobs for two hours at 110°C.
 Soaking of dried corncobs with 0.85% solution of H3PO4 at a ratio of one mile of
H3PO4 to one gram of dried corncobs for two hours
 Heating of soaked corncobs for two hours in an oven at 400 °C.
 Cooling and washing of produced activated carbon with distillated water until pH of
washings reached to 6.
 Finally drying of product activated carbon at 110°C for two hours.
2.2.3. Akualite (Ion Exchange Resin)
Weak acid cation exchange resin of model C-107E (Acualite) with the following
properties, polymer matrix structure of macroporous polymath acrylic cross linked
with divinely benzene, functional group of carboxylic acid (-COO-
), shipping weight
(g/L) of (700–730), operating pH range from 5–14, Maximum operating temperature

of 1000
C, Total exchange capacity (equiv/L, equiv/kg) of dry resin (13.7, 9.4).
Acualite was supplied by scientific bureaus in Iraq, Bagdad. Figure (3) shows the
SEM of akualite before and after adsorption of MB dye. Figures 1 and 2 show the
SEM of akualite and produced activated carbon respectively.
Figure (1) SEM of akualite Figure (2) SEM of produced carbon
2.2. Experimental Arrangement
2.2.1. Radial Flow Reactor
Radial flow regime reactor with flow from external to center pipe was designed by
perforated external and internal pipes located inside back house acrylic reactor. The
external and the internal pipes have a diameter of 10 and 1cm respectively and a
height of 16 cm. Back house acrylic reactor has an inner bottom and top diameters of
14.5 cm and 16.5 cm respectively. The adsorbent forced in between the external and
internal pipes with effective depth (depth in the direction of the flow) equal to (radius
of external pipe 10/2 – radius of internal pipe-1/2) 4.5cm and height equal to 10 cm.
The same volume of (775 ml) from adsorbent materials (commercial activated carbon,
corncob activated carbon and ion exchange resin) used for both radial and vertical
reactors in continuous flow processes.
2.2.2. Vertical Flow Regime Reactor
Vertical flow regime reactor with down flow direction was established in a column of
(8.5cm) inner diameter and (80cm) height. The two ends of column were provided
with plastic sieve of (0.5cm) diameter followed by mesh layer of (0.2mm) diameter to
provide good distribution of flow and to prevent materials form out flow respectively.
The column was packed with the adsorbent of 13.7 cm height between two supporting
layers. Above and bottom of the adsorbent there were (5cm) layer of gravel to prevent
adsorbent from float and to provide a good distribution of flow, these two layers of
gravel were washed after each run and used for all runs without replacing to ensure
that there is no partition in adsorption process. Figures (3) and (4) show radial and
vertical flow reactor respectively.

Figure (3) Radial flow reactor
Figure (4) Vertical flow reactor
3. BATCH EXPERIMENTAL RESULTS
Batch processes are important examples in which the adsorbent moves relative to the
walls of the contaminated vessel. The simplest process involves a specific volume of
wastewater is mixed with a quantity of adsorbent into a container until the pollutant
decreased to desired level for a certain period of time. Batch experimental processes
were conducted to study the effect of various parameters, such as the pH, contact
time, adsorbent dose, agitation speed and initial dye concentration for commercial
activated carbon, corncob activated carbon and ion exchange resin (Akualite). Batch
experimental processes established in bottles of (250 ml) of volume, containing a (100
ml) of methylene blue solution.

3.1. Effect of Solution pH
One of the important factors that affecting the capacity of adsorbent in treatment is the
solution pH. The efficiency of adsorption is dependent on the solution pH, since
variation in value of pH leads to the variation in the degree of ionization of the
adsorptive molecule and the surface properties of adsorbent (Nandi et al., 2009). The
effects of pH on adsorption of methylene blue (MB) dye for commercial activated
carbon, corncob activated carbon and akualite were evaluated using parameter shown
in table (1).
Table (1) adopted parameters for pH effects evaluation
Item Material Dose (g) Time (hr.) speed (rpm) Co (mg/l)
Commercial carbon 0.5 10 250 100
Corncob carbon 0.5 5 250 100
Akualite 0.25 4 270 100
It can be seen (Figure 5), for commercial activated carbon, when the pH increased
from 2 to 6 caused an increase in removal efficiency from 74 to 79% respectively,
decreasing in adsorption efficiency from 78 to 72 % when pH increased from 7 to 12,
the maximum removal efficiency of 79% monitored at pH 6. For corncob activated
carbon, when the pH increased from 2 to 7 caused an increase in removal efficiency
from 80.6 to 94.3% respectively, decreasing in adsorption efficiency from 92.8 to
80.6 % when pH increased from 8 to 12, the maximum removal efficiency of 94.3%
monitored at pH 7. For akualite, when the pH increased from 2 to 10 caused an
increase in removal efficiency from 85.45 to 97% respectively, approximately,
constant removal efficiency in pH (8, 10 and 12), the maximum removal efficiency of
97% monitored at pH 10.
Figure (5) The effects of pH on MB adsorption on to commercial activated carbon,
corncob activated carbon and akualite
3.2. Effect of Contact Time
The effect of contact time shown in figure (6) was investigated to find equilibrium
time of adsorption using the parameters shown in table (1) except of time and pHs of
6,7 and 8 as optimum values for commercial activated carbon, corncob activated
carbon and akualite respectively. It is clear for three adsorbent that the rate of

adsorption is rapid at the beginning and becomes slow in later stages till saturation is
reached. It is basically due to the saturation of the active sites which do not allow
further adsorption to take place. The equilibrium times are 8, 5 and 1.25 hr. for
commercial activated carbon, corncob activated carbon and akualite respectively.
3.3. Effect of Adsorbent Dosage
The effect of the amount dose on the MB dye adsorption was examined using the
parameters shown in table (1) of the agitation speed and the initial dye concentration,
with amount of dose from 0.25 to 1.5 g for commercial and corncob activated carbon
and from 0.1 to 1 g for akualite, optimum pHs values and contact time of 8, 5 and 2
hr., for commercial activated carbon, corncob activated carbon and akualite
respectively. As shown in figure (7) the increasing in adsorbent dosage from 0.25 to
1.5 mg, 0.25 to 1 and 0.1 to 0.7 resulted in an increase of removal efficiency from 59
to 98.56%, 72.73 to 99.99 % and 76.5 to 99.99% for commercial activated carbon,
corncob activated carbon and akualite respectively.
Figure (6) The effect of contact time on adsorption of MB dye onto commercial
activated carbon, corncob activated carbon and akualite
Figure (7) the effect of amount dosage on adsorption of MB dye onto commercial
activated carbon, corncob activated carbon and akualite

3.4. Effect of Agitation Speed
The effect of agitation speed on the equilibrium adsorption was conducted as shown
in figure (8) using the parameters shown in table (1) of the dosage and the initial dye
concentration, optimum pHs and contact times found from pervious steps and
different agitation speeds ranging from 50 to 300 rpm. For commercial activated
carbon, when the agitation speed increased from 50 to 150 resulted in an increase of
removal efficiency from 43 to 75%, approximately constant removal efficiency of
78% in speeds above than 200 rpm. When the agitation speed increased from 50 to
150 resulted in an increase of removal efficiency from 51 to 88% and from 60 t0 91%,
approximately constant removal efficiency of 93 and 96 % in speeds above than 250
rpm for corncob activated carbon and akualite respectively. This behavior due to the
increase in turbulence and the decrease in boundary layer thickness around the
adsorbent particles.
3.5. Effect of Initial Dye Concentration
The effect of initial dye concentration on MB dye adsorption was evaluated as shown
in figure (9) using the parameters shown in table (1) of the dosage and the agitation
speed, optimum pHs and contact times found from pervious steps and different initial
dye concentrations ranging from 50 t0 250 mg/l. When the initial dye concentration
increased from 50 t0 250, the removal efficiency decreased from 89 to 55, 99.5 to
78.6 and from 99.64 to 86.8 for commercial activated carbon, corncob activated
carbon and akualite respectively.
Figure (8) the effect of agitation speed on adsorption of MB dye adsorption on to
commercial activated carbon, corncob activated carbon and akualite

Figure (9) the effect of initial dye concentration on MB dye adsorption for
commercial activated carbon, corncob activated carbon and akualite
3.6. Adsorption Equilibrium Isotherms
The adsorption equilibrium isotherms were represented by the Langmuir and the
Freundlich isotherm models for adsorption of MB dye on to commercial activated
carbon, corncob activated carbon and Akualite. Figures (5.5) and (5.6) show the
Langmuir and the Freundlich isotherms reported for adsorption of MB dye on to
commercial activated carbon at pH 6, contact time 8 hr., agitation speed 250 rpm,
initial concentration 100 mg/l and dosage from 0.5 to 1.5 g. Langmuir and the
Freundlich isotherms conducted for adsorption of MB dye on to corncob activated
carbon at pH 7, contact time 5 hr., agitation speed 250 rpm, initial concentration 100
mg/l and dosage from 0.5 to 1.5 g as shown in figures (10) and (11).
Figure (10) Langmuir isotherm for adsorption of MB dye on to commercial activated
carbon

Figure (11) Langmuir isotherm for adsorption of MB dye on to corncob activated
carbon
Figure (12) show the Langmuir isotherm reported for adsorption of MB dye on to
akualite at pH 8, contact time 2 hr., agitation speed 270 rpm, initial concentration 100
mg/l and dosage from 0.1 to 1 g.
Figure (12) Langmuir isotherm for adsorption of MB dye on to akualite
4. COLUMN EXPERIMENTAL RESULTS
For all three adsorbents (commercial activated carbon, corncob activated carbon and
akualite) and both the radial and vertical regime reactors, the flowrates Q =0.2, 0.3
and 0.4L/min and a concentration dye Co=15mg/L were studied as shown in figures
(13), (14) and (15).

Figure (13) Breakthrough curve for radial and vertical flow regime reactors at Co=15
mg/L, Q= 0.2L/min and pHs 6, 7 and 8 for MB dye adsorption onto commercial
activated carbon, corncob activated carbon and akualite respectively.
Figure (14) Breakthrough curve for radial and vertical flow regime reactors at Co=15
mg/L, Q= 0.3L/min and pHs 6, 7 and 8 for MB dye adsorption onto commercial
activated carbon, corncob activated carbon and akualite respectively.

Figure (15) Breakthrough curve for radial and vertical flow regime reactors at Co=15 mg/L,
Q= 0.4L/min and pHs 6, 7 and 8 for MB dye adsorption onto commercial activated carbon,
corncob activated carbon and akualite respectively.
5. CONCLUSIONS
Based on results of batch and continuous processes and simulation of flow obtained
from the present study, the following conclusions can be written:
 The optimum achieved parameters for methylene blue dye adsorption are: solution
pHs of 6,7 and 8, contact times of 8, 5 and 1.25 hr., adsorbent dosages of 1.5, 0.5 and
0.25 gm, agitation speeds of 200, 250 and 270 rpm and initial dye concentration of 50
mg/l exhibited by commercial activated carbon, corncob activated carbon and
akualite respectively.
 Langmuir model fitted well with the experimental data, with maximum monolayer
adsorption capacities of 16.21, 30.95 and 77.52 mg/g and R2
of 0.952, 0.992 and
0.995 predicted by commercial activated carbon, corncob activated carbon akualite
respectively.
 In radial flow regime reactor, breakthrough curves showed that the outlet
concentration of methylene blue dye at the beginning of run time is higher and the
break point time is larger in comparison with vertical flow regime reactor for most
figures of breakthrough curve.
 The results of continuous flow processes showed that, when the flow rate or initial
dye concentration increase, the time required reaching saturation decreases for both
radial and vertical regime reactors.
 Convergence in the time required reaching saturation between the radial and vertical
regime reactors, as the flow rate or initial dye concentration increase in the results of
continuous flow processes.
 Radial flow regime reactor may be a competitive installation over vertical flow
regime reactor in removing of MB dye from aqueous solution.

 For commercial activated carbon and corncob activated carbon, the time required to
reach the ratio C/Co =0.9 is approximately 20% and 40% respectively of the time
required for akualite to reach the same ratio of C/Co.
 Chemically activated corncob carbon showed good adsorption capacities in
comparison with commercial activated carbon, while akualite exhibited good
adsorption capacities than commercial activated carbon and corncob activated carbon
in both batch and breakthrough curve studies.
 Corncob is a good agriculture source for activated carbon production utilized for MB
dye adsorption in comparison with many agriculture materials utilized for dyes
removal.
REFERENCES
[1] Dai Y., Wang J., Jia S., Yue S., Jia M. and Xu P., (2009), “Study on the
Purification of Polysaccharides from Noscoc flagelliforme with Radial Flow
Chromatography”, Biotechnology and Bioprocess Engineering, Vol.14, pp 377-
382
[2] Fungaroa D.A., Groschea L.C., Pinheirob A.S., Juliana C. Izidoroa, J.C. and
Borrely, S.I., (2010), “Adsorption of methylene blue from aqueous solution on
zeolitic material and the improvement as toxicity removal to living organisms”
electronic journal of chemistry, Vol. 2, No. 3
[3] Gonawala K.H. and Mehta, M. J., (2014), “Removal of color from different dye
wastewater by using ferric oxide as an adsorbent” Engineering Research, Vol. 4,
Issue 5
[4] Gong R., Zhu S., Zhang D., Chen J., Nia S. and Guan R., (2008), “Adsorption
behavior of cationic dyes on citric acid esterifying wheat straw: kinetic and
thermodynamic profile”, Desalination 230 pp 220–228
[5] Hameed, B.H. and El-Khaiary, M.I., (2008) “Malachite green adsorption by
rattan sawdust: Isotherm, kinetic and mechanism modeling” Hazardous Materials,
Vol.159 pp 574–579
[6] Himakshi, Neelakshi and Meena, R. C., (2013), “MBIR DOWEX-11 assisted
photocatalytic degradation of azo dyes: A review” Sci. Revs. Chem., Vol.3(4), pp
181-189
[7] Idris, S., Ndamitso, M.M., Iyaka, Y. A. and Muhammad, E. B., (2012), “Sawdust
as an Adsorbent for the Removal of Methylene Blue from Aqueous Solution:
Adsorption and Equilibrium Studies”, Chemical engineering Vol. 1, No. 1
[8] Kauspediene D., Kazlauskiene E., Cesuniene R., Gefeniene A., Ragauskas R.,
Selskiene A., (2013), “Removal of the phthalocyanine dye from acidic solutions
using resins with the polystyrene divinylbenzene matrix”, chem. vol. 24, No. 3,
pp 171–181
[9] Li R. and Zhu Z., (2011), “Investigations on hydrodynamics of multilayer –type
radial flow reactors”, Chem. Eng. Vol. 7, pp 517–527
[10] Mohammed, M.A., Shitu, A. and Ibrahim A., (2014), “Removal of Methylene
Blue Using Low Cost Adsorbent: A Review”, Chem. Sci. Vol. 4(1), pp 91-102
[11] Olivella M.A., Fiol N., Torr F.D., Poch J. and Villaescusa, I., (2012), “A
mechanistic approach methylene blue sorption on two vegetable wastes: cork
park and grab stalk” bioresources 3340-3354
[12] Rocha P.D., Franca A.S. and Oliveira L.S., (2015), “Batch and column studies of
phenol adsorption by an activated carbon based on acid treatment of corn cobs”,
IACSIT, International Journal of Engineering and Technology, Vol. 7, No. 6.

[13] Taha D.N., Samaka I.S., Luma Ahmed Mohammed L.A. and Saib A., (2014)
“Adsorption Studies of Direct Red 28 Dye onto Activated Carbon Prepared from
Low Cost Material” Civil and Environmental Research, Vol.6, No.7
[14] Wang Y. X., Liu B. S., and Zheng C., (2010), “Preparation and Adsorption
Properties of Corncob-Derived Activated Carbon with High Surface Area”,
Chem. Eng. Vol. 55, pp 4669–4676.
[15] Prof. Dr. Mohammad Abid Moslim Al-Tufaily and Zahraa Ali Hmoud. Using of
Wasted Filings of Iron To Adsorb Methylene Blue Dye From Aqueous Solution,
International Journal of Advanced Research in Engineering and Technology,
5(4), 2014, pp. 57-67.
[16] Yan, T. and Wang, L., (2013), “Adsorptive removal of methylene blue from
Aqueous Solution by spent mushroom substrate: Equilibrium, kinetics and
thermodynamic” J. of Bioresources, Vol. 8(3), pp 4722-4734
[17] Zainol, N. I. B., (2010), “Biosorption of iron (II) and methylene blue using tea
waste”, Thesis, Faculty of Chemical and Natural Resources Engineering,
University of Malaysia.
[18] Prof. Dr. Mohammad Abid Moslim Al-Tufaily and Wisam Sh. Jabir Al- Salami.
Computerize Rcra, Ewc and Bc Hazardous Wastes Classification System Using
Visual Basic- 6 Language, International Journal of Civil Engineering and
Technology, 5(1), 2014, pp. 111-124.

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