Environmental
Communication
Biosci. Biotech. Res. Comm. 10(1): 241-248 (2017)
Kinetics and mechanism of red mud in adsorption
of cipro oxacin in aqueous solution
Davoud Balarak
1
, Ferdos Kord Mostafapour
1
and Ali Joghataei
2
1
Department of Environmental Health, Health Promotion Research Center, School of Public Health, Zahedan
University of Medical Sciences, Zahedan, Iran
2
MSc Student of Environmental Health Engineering, Student Research Committee, Qom University of Medical
Sciences, Qom, Iran
ABSTRACT
The objective of this study is to remove the Cipro oxacin (CPX), from synthetic wastewater by using the acid acti-
vated red mud in batch adsorption experiments. The effects of contact time, adsorbent dosage and initial CPX con-
centration on the adsorption were investigated. It was found that the suf cient time to attain equilibrium was 75 min.
The adsorption isotherms were analyzed using the Langmuir, the Freundlich, Temkin and Dubinin Radushkevich iso-
therms. The Freundlich isotherm was the best- t adsorption isotherm model for the experimental data obtained from
the linear chi-square statistic test. The maximum adsorption capacities were 19.12 at room temperature according to
the Langmuir model. The adsorption kinetics analysis indicates that pseudo-second order model is better tted than
other kinetics model for the description of the adsorption rate. The results show that the highest removal ef ciency
of 96.5% was achieved around adsorbent sosage 5 g/L.
KEY WORDS: RED MUD, CIPROFLOXACIN, ADSORPTION, KINETICS, ISOTHERMS
241
ARTICLE INFORMATION:
*Corresponding Author: alijoghatayi69@gmail.com
Received 11
th
Nov, 2016
Accepted after revision 29
th
March, 2017
BBRC Print ISSN: 0974-6455
Online ISSN: 2321-4007 CODEN: USA BBRCBA
Thomson Reuters ISI ESC and Crossref Indexed Journal
NAAS Journal Score 2017: 4.31 Cosmos IF : 4.006
© A Society of Science and Nature Publication, 2017. All rights
reserved.
Online Contents Available at: http//www.bbrc.in/
INTRODUCTION
For the last years the interest towards the fate of medi-
cines, especially antibiotics, has been arising,(Alexy
et al., 2004 and Balarak et al., 2016a). Being refrac-
tory substances, antibiotics pass the biological treat-
ment plants intact, either remaining in the liquid phase
or, dependent on their hydrophilicity, adsorbing to the
active sludge with subsequent desorption to the envi-
ronment, (Johnson and Mehrvar (2008) and Choi etal.,
2008). Pharmaceuticals are considered as an emerging
environmental problem due to their continuous input
and persistence into the aquatic ecosystem even at low
concentrations,( Aksu and Tunc 2005 and Balarak etal
2016 b).
After their use, human pharmaceuticals or their
metabolites are excreted into the ef uents and reach
the sewage treatment plants (STPs) ( Balarak etal 2016c
Balarak, Mostafapour and Joghataei
mud is a ne-grained mixture of oxides and hydrox-
ides, capable of removing several contaminants, as well
as being widely available, (Claudia etal., 2005, Weiwei
etal., 2008, Wang etal., 2008, and Tor and Cengeloglu
2006). However, the studies about utilization of acti-
vated red mud for removal of antibiotics from aqueous
solution are very rare. Therefore, in the present paper,
the possibility of utilisation of the red mud in the acid
activated form as an adsorbent for removal of CPX from
synthetic wastewater was studied.
MATERIAL AND METHODS
Cipro oxacin with molecular weight 331.34 g/mol and
maximum adsorption 285 nm. The CPX (C
17
H
18
FN
3
O
3
)
was purchased from Sigma–Aldrich (>98% purity) and
used without further puri cation.
Red mud was washed thoroughly with distilled water,
dried at 110
o
C for 24 hours. 10 grams of washed red mud
was soaked in 200 ml of 1N H
2
SO
4
for 24 hours, washed
with water several times and dried at 110
o
C overnight.
The acid treated red mud sample thus prepared was
sieved and the sample of average size 120 microns was
used for the studies. Scanning Electronic Microscopy
(SEM) was carried out for surface morphology to com-
pare the relative performance of raw and acid treated
red mud. The surface areas of original red mud and acid
treated red mud were determined by BET analysis using
ASAP 2020 V3.04 H, Micromeritics, USA surface area
analyzer.
Batch adsorption experiments were carried out in 200
mL asks with 100 mL of working volume. 5 grof RM
and determined amounts of stock solution were added
into asks and diluted to designed concentrations. The
initial pH of the solution was adjusted to 6.5 ± 0.2 using
0.1M HCl or 0.1M NaOH. The loaded asks were sealed
and shaken at an air rotary shaker with 200 rpm for
75 min. The adsorption was examined at 28±2
o
C. A
blank adsorption experiment without RM addition was
conducted following the same procedure as the control.
Each test was carried out in triplicate and the average
was reported here. Liquid samples were collected from
the asks at predetermined time intervals. The collected
and Su etal., 2016). Unfortunately, conventional STPs
are not able to degrade residues of pharmaceutical com-
pounds, and as a result they are introduced into the
aquatic environment. Residual amounts of pharmaceuti-
cals can reach surface waters, groundwater or sediments.
Many studies have reported a large number of pharma-
ceuticals at concentrations ranging from ng/L to g/L in
STP ef uents, in natural waters and even in drinking
water. Cipro oxacin (CPX) is one of the most used anti-
biotics in aquaculture and veterinary medicine. It has
been monitored either in super cial or in potable waters,
(Hu etal., 2007, Ji etal 2002, 2009, Jianga etal., 2013,
Genec etal., 2013, Zhang etal 2016, Su etal., 2016 and
Yu etal., 2016).
Although the amount of drugs introduced in the
medium through these routes may be low, its continu-
ous discharge could cause high concentrations in the
long term and adverse effects in terrestrial and aquatic
organisms. These effects can be slowly accumulated, so
that the changes show up suddenly and irreversibly. On
the other hand, it could be supposed that pharmaceuti-
cals are susceptible of degradation through microorgan-
isms’ action, but not all drugs are biodegradable. The
case of antibiotics is obvious, because they are biologi-
cally active, and so they have limited biodegradability.
A clear example is the fact that, in the last decades, the
increase in antibiotics consumption has resulted in the
generation of more harmful bacteria, more resistant to
antibiotics. The adsorption process is another attractive
alternative treatment process if the adsorbent is inex-
pensive and readily available, (Dutta etal., 1999,Zhang
et al., 2003,Gao and Pedersen (2005) Gulkowsk et al.,
2008, Kassinos etal,2011, Peterson etal, 2012 and Bal-
arak etal. 2016 d).
Activate carbon is the most powerful and common
adsorbent and has been used successfully. But the high
cost in the preparation of activated carbon restricts its
use in the industrial wastewater treatment, especially
in the developing countries, (Chen and Huang 2010).In
recent years, many studies have been done on the non-
conventional and economic adsorbents, especially those
researches on making use of industrial solid waste. Using
an industrial solid waste for the treatment of wastewa-
ters from another industry could be helpful not only to
the economy, but also to solve the solid waste disposal
problem, (Zhang etal., 2003, Zhu etal., 2013 and Parolo
etal., 2008).
Red mud (RM), (bauxite wastes of alumina manu-
facture) emerges as an unwanted byproducts during
alkaline-leaching of bauxite in Bayer process, which is
used for the production of alumina from bauxite. Stud-
ies using red mud residues from alumina re neries as
unconventional adsorbents for water and wastewater
treatment purposes are motivated by the fact that red
FIGURE 1. Chemical structure
of CPX.
242 KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Balarak, Mostafapour and Joghataei
liquid samples were centrifuged at 4000 rpm for 10 min
and the supernatant was passed through 0.45 μm l-
ter for the determination of residual tetracycline con-
centration. CPX concentrations are measured by liquid
chromatography (HPLC) coupled to a photodiode array
detector (PDA, Surveyor, Thermo Scienti c, USA). A
Luna C18 column (150 mm×3.0 mm, 3 M, Phenomenex,
USA) with a mobile phase containing 87.5% water (0.1%
formic acid) and 12.5% acetonitrile is used for the chro-
matographic analysis of CPX.
The amount of CPX adsorbed was calculated from the
following equation:
where q
e
is the amount of CPX adsorbed per unit weight
of activated red mud (mg/g); C
0
the initial concentration
of CPX (mg/L); C
e
the concentration of CPX in solution
at equilibrium time (mg/L); V the solution volume (L); m
is the activated red mud dosage (g).
RESULTS AND DISCUSSION
The raw RM and acid treated RM have speci c surface
area of 21.4 and 28.7 m
2
/g respectively. The pore size of
raw RM and acid treated RM was 18.75 nm and 17.44
nm respectively. The surface area and pore volume of
acid treated RM is higher than the raw RM.
SEM of RM after and before CPX adsorbed are shown
in Fig. 2a and b. It is clear that, RM has considerable
numbers of pores where, there is a good possibility for
CPX to be trapped and adsorbed into these pores.
RM is found to be a complex mixture of phases
mainly comprising of Hematite (Fe
2
O
3
),Goethite FeO(OH)
and Quartz (SiO
2
). The surface of the RM activated by
acid pretreatment was compared with that of raw RM
using the results of scanning electron microscopy. The
SEM-EDAX micrograph of raw RM and acid treated
RM samples are shown in Fig 3a and b. EDAX analysis
shows that the intensity for metals like Al, Si, Ti and Fe
in raw RM are high. Acid treatment of RM has resulted
in drastically decreased intensities for Fe, Ti, Si and Al.
Effect of contact time and initial CPX concentration
Fig 4 shows the effect of contact time and initial con-
centration on adsorption of CPX by RM. The removal
of CPX Was rapid at initial stage of contact time until
saturation. The equilibrium time was 75 min for all the
CPX Concentation used (10-100 mg/L). This may be due
to the attainment of equilibrium condition at 75 min
of contact time, which is xed as the optimum contact
time. At the initial stage, the rate of the removal of CPX
was higher, due to the availability of more than required
number of active sites on the surface of adsorbent. The
rate of the removal became slower at the later stages of
contact time, due to the decreased or lesser number of
active sites.Low etal 2007, Tor and Cengeloglu 2006 and
Balarak etal., 2016e )
FIGURE 2. SEM image of Red mud before and after CPXadsorbed.
FIGURE 3. The SEM- EDAX micrograph of a: raw red mud b: red mud treated
with H
2
SO
4
.
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN 243
Balarak, Mostafapour and Joghataei
FIGURE 4. Effect of contact time and concentration on
CPX removal (pH =7, Adsorbent dosage 5 g/L and tem-
perature= 28±2°C).
FIGURE 5. Effect of adsorbent dosage on CPX
adsorption (C0 = 50 mg/L, time = 75 min, pH = 7,
temp= 28 ± 2°C).
The uptake of CPX at equilibrium decreased from 96.5
to 78.4 with the increase of CPX concentration from 10
to 100 mg/L. It can be attributed that the active sites on
adsorbent for CPX removal decreases when CPX con-
centration increases, (Putra etal., 2009).
Effect of adsorbent dose
Fig 5 shows that the removal of CPX increased with the
increase in adsorbent dosage and reached a maximum
of 25.2 mg/g (89.6%) at 5 g/L of adsorbent dose. The
increase in the amount of CPX removal with adsorbent
dosage is due to the greater availability of adsorbent
surface area for adsorption ( Ahmad etal. 2012, Zazouli
etal., 2014).
Adsorption Kinetics: Kinetics is key factor for adsorp-
tion investigation because it can predict the rate at
which a pollutant is removed from aqueous solution and
provides valuable data for understanding the mecha-
nism of adsorption process. Several models are available
to investigate the adsorption mechanism and descrip-
tion based on experimental data such as pseudo- rst
order, pseudo-second order, intramolecular diffusion
and Elovich models. The pseudo- rst order adsorption
rate and pseudo-second order adsorption rate have the
following linear forms, (Ersen and Bagd 2013, Ghauch
etal., 2009 and Balarak etal., 2015).
Where k
1
(min
−1
) is pseudo rst order rate constant, q
e
(mg g
−1
) is the amount of CPX adsorbed on surface at
equilibrium, q
t
(mgg
−1
) is the amount of CPX adsorbed
on surface at time t (min). The adsorption rate constant,
k
1
and q
e
were calculated from the plot of log(q
e
-q
t
) vs t,
and are listed in Table 1.
Where, k
2
(g mg
−1
min
−1
) is pseudo second order rate
constant. The adsorption rate constant, q
e
and k
2
were
calculated from the plot of t/q
t
vs t, and are listed in
Table 1. The correlation coef cient of pseudo rst order
kinetics (0.941) is not lower than that of second order
kinetics (0.997). Consequently pseudo second order
kinetics is tted.
Intraparticle diffusion
The limiting step in CPX adsorption may be either the
boundary lm formation or intraparticle (pore) diffu-
sion of the CPX on the solid surface from bulk of solu-
tion. Weber and Morris explain the diffusion mechanism
through the following equation:
C is the intercept that its value provides information
about the thickness of boundary layer. K is intraparticle
diffusion rate constant (mg g
−1
min
−0.5
) which are evalu-
ated from the intercept and slope of plot q
t
and t
1/2
.
Elovich
It is another rate equation in which the absorbing sur-
face is heterogeneous. It is represented as:
is the initial adsorption rate (mg g
−1
min
−1
). is the
desorption constant (g mg
−1
) which are calculated from
intercept and slope of plot q
t
versus lnt.
244 KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Balarak, Mostafapour and Joghataei
Adsorption Isotherm Models: The equilibrium data of
CPX analyzed by tting them into Langmuir, Freun-
dlich, Temkin and Dubinin Radushkevich equation to
nd out the suitable model that may be used for design
consideration.
Langmuir Isotherm
The Langmuir isotherm assumes the absence of any
interactions between adsorbate molecules and the
adsorption process is account for monolayer forma-
tion. The linear form of the Langmuir isotherm, assum-
ing monolayer adsorption on a homogeneous adsorbent
surface, is expressed as follows:
Where q
max
(mg∙g
−1
) is the maximum adsorption capac-
ity of the adsorbent corresponding to monolayer forma-
tion and illustrates the maximum value of q
e
that can
be attained as C
e
is increased. The b parameter is a coef-
cient related to the energy of adsorption and increases
with increasing strength of the adsorption bond. Values
of q
max
and b are determined from the linear regression
plot of (C
e
/q
e
) versus C
e
. Linear plot in negative direc-
tion indicates that Langmuir model fails to explain the
process of adsorption and absence of formation of mon-
olayer.
Freundlich Isotherm
It is well established that the Freundlich isotherm is often
applied to heterogeneous solid catalyst. The Freundlich
equilibrium isotherm equation is an empirical relation
involved for the description of multilayer adsorption with
interaction between adsorbed molecules. The Freundlich
equation is expressed as follows in its linear form, (Rosta-
mian and Behnejad 2016, Balarak etal, 2016 g),
where, K
F
represents the capacity of the adsorbent for
the adsorbate, and 1/n shows adsorption intensity of
CPX on solid which is a function of the strength of
adsorption. A linear regression plot of log q
e
versus log
C
e
, gives the K
F
and n values. The model is applicable to
the adsorption on heterogeneous surfaces by a uniform
energy distribution and reversible adsorption. Linear
plot with high regression factor indicating the success-
ful model in explaining the adsorption model.
Temkin Isotherm
The Temkin model takes into the account adsorbing
species–adsorbent interactions. This isotherm proposed
that the heat of adsorption of all the molecules in the
layer decreases linearly with coverage due to adsorbent–
adsorbate interactions and the adsorption is character-
ized by a uniform distribution of binding energies, up
to some maximum binding energy. The linear Temkin
equation is(48, 49):
is the equilibrium constant corresponding to the maxi-
mum binding energy.
T is the absolute temperature in Kelvin. R is the uni-
versal gas constant 8.314 J.mol
−1
.K
−1
. b is the Temkin
constant related to heat sorption/J∙mg
−1
.
A and are calculated from the slope and intercept
of q
e
versus ln C
e
. The Temkin equation better holds for
the prediction of gas phase equilibria rather than liquid
phase. The liquid phase is a more complex phenomenon
since the adsorbed molecules do not necessarily organ-
ized in a tightly packed structure with identical orienta-
tion. Linear plot and high regression value suggest the
successful model in explaining the adsorption mecha-
nism.
Dubinin Radushkevich Isotherm
This model is involved to estimate the porosity, free
energy and the characteristics of adsorbents. The iso-
therm assumes the surface heterogeneity and the vari-
ation of adsorption potential during sorption process.
The model has commonly been applied in the following
linear Equation: (Zazouli etal., 2015):
Table 1. Adsorption kinetics constants of adsorption of CPX onto RM
First-order model Second-order model Weber-Morris model Elovich model
qe mg/g exp qe cal k
1
R
2
qe cal k
2
R
2
kCR
2
R
2
19.25 17.06 0.125 0.941 20.14 0.748 0.997 0.642 0.749 0.876 4.112 0.847 0.904
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN 245
Balarak, Mostafapour and Joghataei
Polanyi potential, , can be calculated according the fol-
lowing equation, (Peng etal., 2012):
Where B is a constant related to the adsorption energy
(mol
2
J
−2
), qm the theoretical saturation capacity. Table
2 summarizes Dubinin constants. The mean free energy
of adsorption (E) which is energy require to transfer one
mole of the CPX from in nity in solution to the surface
of the solid can be calculated from the B value using the
following relation,( Chang etal., 2012).
Table 2 summarizes isotherm constants. The results of
Freundlich, Langmuir, Temkin and Dubinin Radushk-
evich models suggest that adsorption of CPX is accom-
panied by multilayer formation. The adsorption energy
obtained from Temkin plot 368.08 J.mg
−1
which indi-
cates that the adsorption process is endothermic and a
strong interaction between RM and CPX. The value of
energy is about 875.2 J/mole revealing physisorption of
CPX on RM.
CONCLUSIONS
The adsorption removal of Cipro oxacin by Red Mud was
investigated in this study. The highest removal ef ciency
of CPX 96.5% was was achieved around adsorbent sosage
5 g/L. The removal ef ciency of CPX was affected by the
adsorbent dose and the concentration of CPX antibiotics
in the solution and contact time. The adsorption isotherms
analysis shows that Freundlich model is better tted than
other isotherm models for the adsorption equilibrium. The
adsorption behavior of CPX on RM stone was tted well
in the pseudo-second order kinetics model.
REFERENCES
Ahmed MJ, Theydan SK.(2012) Adsorption of cephalexin onto
activated carbons from Albizia lebbeck seed pods by micro-
wave-induced KOH and K2CO3 activations. Chemical Engi-
neering Journal 211-212; 200–7.
Aksu Z, Tunc O.(2005) Application of biosorption for Penicillin
G removal: Comparison with activated carbon. Process Bio-
chemistry. 40(2):831-47.
Alexy R, Kumpel T, Kummerer K.(2004) Assessment of degra-
dation of 18 antibiotics in the closed bottle test. Chemosphere;
57, 505–512.
Balarak D, Azarpira H, Mostafapour FK. (2016 c)Thermody-
namics of removal of cadmium by adsorption on Barley husk
biomass. Der Pharma Chemica,8(10):243-247.
Balarak D, Azarpira H, Mostafapour FK. (2016) Study of the
Adsorption Mechanisms of Cephalexin on to Azolla licu-
loides. Der Pharma Chemica, 8(10):114-121.
Balarak D, Jaafari J, Hassani G, Mahdavi Y, Tyagi I, Agarwal S,
Gupta VK. (2015) The use of low-cost adsorbent (Canola resi-
dues) for the adsorption of methylene blue from aqueous solu-
tion: Isotherm, kinetic and thermodynamic studies. Colloids
and Interface Science Communications. Colloids and Interface
Science Communications. 7:16–19.
Balarak D, Mahdavi Y and Mostafapour FK.(2016 b) Appli-
cation of Alumina-coated Carbon Nanotubes in Removal of
Tetracycline from Aqueous Solution. British Journal of Phar-
maceutical Research; 12(1): 1-11.
Balarak D, Mahdavi Y, Maleki A, Daraei H and Sadeghi S.
(2016a)Studies on the Removal of Amoxicillin by Single
Walled Carbon Nanotubes. British Journal of Pharmaceutical
Research. 10(4): 1-9.
Balarak D, Mahdavi Y, Bazrafshan E , Mahvi AH. (2016e)
Kinetic, isotherms and thermodynamic modeling for adsorp-
tion of acid blue 92 from aqueous solution by modi ed Azolla
licoloides. Fresenius Environmental Bulletin.25(5); 1321-30.
Balarak D, Mahdavi Y, Bazrafshan E, Mahvi AH, Esfandyari
Y.(2016f) Adsorption of uoride from aqueous solutions by
carbon nanotubes: Determination of equilibrium, kinetic and
thermodynamic parameters. Flouride. 49(1):35-42.
Balarak D, Mostafapour FK, Joghataei A.( 2016) Experimen-
tal and Kinetic Studies on Penicillin G Adsorption by Lemna
minor. British Journal of Pharmaceutical Research. 9(5):
1-10.
Balarak D.(2016) Kinetics, Isotherm and Thermodynamics
Studies on Bisphenol A Adsorption using Barley husk. Interna-
tional Journal of ChemTech Research ;9(5);681-690.
Chang PH, Li Z, Jean JS, Jiang WT, Wang CJ, Lin KH.(2012)
Adsorption of tetracycline on 2:1 layered non-swelling clay
mineral illite. Appl. Clay Sci. 67;158–163.
Chen WR, Huang CH. (2010)Adsorption and transformation of
tetracycline antibiotics with aluminum oxide. Chemosphere.
79, 779–785
Choi KJ, Kim SG, Kim SH. (2008) Removal of antibiotics by
coagulation and granular activated carbon ltration. J. Haz-
ard. Mater.151;38–43.
Table 2. Isotherms constants for the removal CPX onto RM
Langmuir model Freundlich model Dubinin Radushkevich Temkin model
qm RL KL R
2
nKFR
2
BqmE R
2
R
2
19.12 0.461 0.038 0.964 3.29 1.874 0.985 6.52 17.44 875.2 0.928 6.731 0.844 0.911
246 KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Balarak, Mostafapour and Joghataei
Dutta M, Dutta NN, Bhattachary KG.(1999) Aqueous phase
adsorption of certain beta-lactam antibiotics onto polymeric
resins and activated carbon. Separation and Puri cation Tech-
nology.16(3);213-24.
Er
s
˛an M, Ba
g
˘ d E.(2013) Investigation of kinetic and thermody-
namic characteristics of removal of tetracycline with sponge
like, tannin based cryogels. Colloids and Surfaces B: Biointer-
faces. 104;75-82.
Gao J and Pedersen JA. (2005)Adsorption of Sulfonamide
Antimicrobial Agents to Clay Minerals. Environ. Sci. Technol.
39(24). 9509-16.
Gao Y, Li Y, Zhang L, Huang H, Hu J, Shah SM, Su X.(2012)
Adsorption and removal of tetracycline antibiotics from aque-
ous solution by graphene oxide, J. Colloid. Interface Sci. 368;
540–546.
Garoma T, Umamaheshwar SH, Mumper A. (2010) Removal of
sulfadiazine, sulfamethizole, sulfamethoxazole, and sulfathiazole
from aqueous solution by ozonation. Chemosphere. 79;814–20.
Genç N,Can Dogan E,Yurtsever M.(2013) Bentonite for cip-
ro oxacin removal from aqueous solution. Water Sci Tech-
nol.68(4):848-55.
Ghauch A, Tuqan A, Assi HA: Elimination of amoxicillin and
ampicillin by micro scale and nano scale iron particles. Envi-
ron Pollut 2009,157:1626–1635.
Gulkowsk A, Leung HW, So MK, Taniyasu S, Yamashita N.
(2008) Removal of antibiotics from wastewater by sewage
treatment facilities in Hong Kong and Shenzhen, China. Water
research. 42:395-403.
Haq, I. Bhatti, HN. Asgher, M. (2011)Removal of solar red BA
textile dye from aqueous solution by low cost barley husk:
Equilibrium, kinetic and thermodynamic study. Canadian
Journal of Chemical Engineering. 89(3);593–600.
Ji K, Kim S, Han S, Seo J, Lee S, Y.(2012) Risk assessment of
chlortetracycline, oxytetracycline, sulfamethazine, sulfathiazole,
and erythromycin in aquatic environment: are the current envi-
ronmental concentrations safe?, Ecotoxicology 21;2031-2050.
Ji L, Chen W, Duan L and Zhu D. (2009) Mechanisms for strong
adsorption of tetracycline to carbon nanotubes: A compara-
tive study using activated carbon and graphite as adsorbents.
Environ. Sci. Technol. 43 (7), 2322–27.
Jianga WT, Changa PH,Wanga YS,Tsaia Y,Jeana JS,Zhaohui
Lia Z,(2013)Removal of cipro oxacin from water by birnessite,
Journal of Hazardous Materials. 250–251, 362–36.
Johnson MB, Mehrvar M.(2008) Aqueous metronidazole deg-
radation by UV/H2O2 process in single-and multi-lamp tubu-
lar photoreactors: kinetics and reactor design, Ind. Eng. Chem.
Res. 47; 6525–6537.
Kassinos F D, Meric S, Nikolau A. (2011) Pharmaceutical resi-
dues in environmental waters and wastewater: current state
of knowledge and future research, Anal. Bioanal. Chem. 2011;
399; 251-275.
Lanhua Hu L, Flanders PM, Penney L. Miller PL, Timothy J.
Strathmann TJ.(2007) Oxidation of sulfamethoxazole and
related antimicrobial agents by TiO2 photocatalysis Water
Research 2007;41(12); 2612-26.
Low KS, Lee CK, Tan BF.(2000) Quaternized wood as sorbent
for reactive dyes. Biochem Biotechnol. ;87:233-45.
Peng H, Pana B, Wu M, Ran Liu R, Zhanga D, Wu D, Xing
B.(2012)Adsorption of o oxacin on carbon nanotubes: Solu-
bility, pH and cosolvent effects. Journal of Hazardous Materi-
als. 211-212;342-48.
Peng X, Hu F, Dai H, Xiong Q. (2016) Study of the adsorption
mechanism of cipro oxacin antibiotics onto graphitic ordered
mesoporous carbons. Journal of the Taiwan Institute of Chemi-
cal Engineers. 8; 1–10.
Peterson JW. Petrasky LJ, Seymourc MD, Burkharta RS, Schu-
ilinga AB.(2012) Adsorption and breakdown of penicillin anti-
biotic in the presence of titanium oxide nanoparticles in water.
Chemosphere. 87(8); 911–7.
Putra EK, Pranowoa R, Sunarsob J, Indraswatia N, Ismadjia
S. (2009) Performance of activated carbon and bentonite for
adsorption of amoxicillin from wastewater: mechanisms, iso-
therms and kinetics. Water Res. 43, 2419-2430.
Robinson, T. Chandran, B. Nigam, P. (2002)Removal of dyes
from an arti cial textile dye ef uent by two agricultural waste
residues, corncob and barley husk. Environment International.
28(1-2);29–33.
Rostamian R, Behnejad H. (2016) A comparative adsorp-
tion study of sulfamethoxazole onto graphene and graphene
oxide nanosheets through equilibrium, kinetic and thermody-
namic modeling. Process Safety and Environmental Protec-
tion.102;20-29.
Su YF, Wang GB, Kuo DTF, Chang ML.(2016) Photoelectro-
catalytic degradation of the antibiotic sulfamethoxazole using
TiO2/Tiphotoanode. Applied Catalysis B: Environmental.
186;184-192.
Su YF, Wang GB, Kuo DTF, Chang ML, Shih YH.(2016) Photo
electrocatalytic degradation of the antibiotic sulfamethoxazole
using TiO
2
/Ti photoanode. Applied Catalysis B: Environmental.
186;184–192.
Tor A, Cengeloglu Y. (2006) Removal of Congo red from aque-
ous solution by adsorption onto acid activated red mud. J Haz-
ard Mater 138(2): 409-15.
Wang S, Ang HM, (2008)Novel applications of red mud as
coagulant, adsorbent and catalyst for environmentally benign
processes. Chemosphere 72(11):1621-35.
Weiwei H, Shaobin W, Zhonghua Z, Li L, Xiangdong Y, Victor
R (2008) Phosphate removal from wastewater using red mud.
Journal of Hazardous Materials158: 35–42.
Yu F, Li Y, Han S, Jie Ma J. (2016) Adsorptive removal of anti-
biotics from aqueous solution using carbon Materials. Chem-
osphere153;365–385.
Zazouli MA, Mahvi AH, Dobaradaran S, Barafrashtehpour
M, Mahdavi Y, Balarak D.(2014) Adsorption of uoride from
aqueous solution by modi ed Azolla liculoides. Fluoride.
47(4):349-58.
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN 247
Balarak, Mostafapour and Joghataei
Zazouli MA, Mahvi AH, Mahdavi Y, Balarakd D.(2015) Isother-
mic and kinetic modeling of uoride removal from water by
means of the natural biosorbents Sorghum and Canola. Fluo-
ride;48(1):15-22.
Zhang L, Song X, Liu X, Yang L, Pan F, Lv J. (2011) Studies on
the removal of tetracycline by multi-walled carbon nanotubes,
Chem. Eng. J. 178;26–33.
Zhang W, He G, Gao P, Chen G: (2003)Development and char-
acterization of composite nano ltration membranes and their
application in concentration of antibiotics. Sep Purif Technol
30:27–35.
Zhang W, He G, Gao P, Chen G: (2003)Development and char-
acterization of composite nano ltration membranes and their
application in concentration of antibiotics. Sep Purif Technol
2003, 30:27–35
Zhu XD, Wang YJ, Sun RJ, Zhou DM. Photocatalytic degrada-
tion of tetracycline in aqueous solution by nanosized TiO2.
Chemosphere. 92; 925–932.
248 KINETICS AND MECHANISM OF RED MUD IN ADSORPTION OF CIPROFLOXACIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS