Iranica Journal of Energy and Environment 7(2): 129-136, 2016

Please cite this article as: R. Alrozi, N. S. Anuar, F. Senusi, M. A. Kamaruddin, 2016. Enhancement of Remazol Brilliant Blue R Adsorption Capacity by using Modified Clinoptilolite, Iranica Journal of Energy and Environment 7 (2): 129-136.

Iranica Journal of Energy & Environment

Journal Homepage: www.ijee.net IJEE an official peer review journal of Babol Noshirvani University of Technology, ISSN:2079-2115

Enhancement of Remazol Brilliant Blue R Adsorption Capacity by using Modified

Clinoptilolite R. Alrozi1*, N. S. Anuar1, F. Senusi1, M. A. Kamaruddin2 1Faculty of Chemical Engineering, UniversitiTeknologi MARA Pulau Pinang, 13500 PermatangPauh, Penang 2School of Civil Engineering, UniversitiSains Malaysia, 14300 NibongTebal, Penang

P A P E R I N F O

Paper history: Received 22July 2015 Accepted in revised form 15December 2015

Keywords: Adsorption Clinoptilolite RBBR Kinetic Isotherm models

A B S T R A C T

In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by

using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The

adsorption experiments were carried out under different conditions of initial concentration (25-250 mg/L), adsorption time (0-2h), solution pH (2-12), and temperature (300-353 K) to determine

optimum conditions for the highest RBBR removal. The influence of these parameters on the

adsorption capacity was studied using the batch process. The results indicated that the solution pH was observed to be a key factor of the RBBR adsorption process. The maximum dye adsorption was

achieved with Zn-CL adsorbent at pH~6 and the corresponding adsorption capacity was found to be

42.2 mg/g, which was higher than R-CL (12.5 mg/g). Lower adsorption capacity of RBBR was found by Zn-CL between pH 8 and 12 opposite to R-CL which showed a marginal increase in

adsorption capacity within the same pH range. The results proved that Zn-CL which is a modified

clinoptilolite is an effective adsorbent for the removal of RBBR from aqueous solution.

doi: 10.5829/idosi.ijee.2016.07.02.07

INTRODUCTION1 Reactive dyes have been extensively used intextile

dyeing by which, significant amount of these types of

dyes are released into the receiving water without

appropriate and efficient treatment [1]. As a result,

reoxygenation of water will be retarded due to limited

sunlight penetration into the water surface.

Nevertheless, reactive dyes are the most common dye

employed in textile related industry due to their

beneficial characteristics including bright color, water

fastness, simple application techniques and low energy

consumption. As a matter of fact, most of the dyes used

in the industry nowadays carries significant amount of

coloring materials that are toxic and harmful to

organisms and human well being [2]. Up to 40% of the

color is discharged in the effluent from reactive dyeing

*Corresponding author: O. A. Oyelaran

E-mail: rasyidah.alrozi@ppinang.uitm.edu.my;

Tel:+04-3822445; Fax: +04-3822812

operation resulting in a highly colored effluent. They are

not easily biodegradable, thus, even after extensive

treatment, color may still remain in the effluent [3].

Therefore, there is a need to effectively remove

these dyes from wastewater and some of the available

methods to remove the dyes including chemical

precipitation, adsorption, ion exchange, flotation,

membrane filtration, electrochemical treatment and

coagulation-flocculation. Until now, adsorption has

been the most favourable process than others and this

process has become more efficient if low-cost

adsorbents are used [4].

Natural zeolites are crystalline hydrated alumina

silicates with a framework structure adsorbent. Zeolite

normally exhibit pores occupied with, alkali and

alkaline earth cations. They are abundant in nature,

which can be obtained at low cost. The advantages of

high cation-exchange and having the characteristics of

molecular sieve properties, natural zeolites have been

widely used as adsorbents in separation and purification

for many years [5]. Akgl [1] found that the properties

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of zeolites external surface can be tailored for specific

applications through surface functionalization. These

modifications can alter physical and chemical properties

of the zeolites and the resulting modified zeolite can be

used for a variety of applications such as ion-exchange,

adsorption, catalysis, etc. [1, 6-7].

In this study, raw clinoptilolite was modified via

Zn2+-grafting to prepare a functionalized zeolite material

that enhanced adsorptive properties for remazol brilliant

blue R (RBBR) in aqueous solution. The dye adsorption

capacity of the resulting modified zeolite was evaluated

to determine the adsorption characteristics for RBBR.

MATERIALS AND METHODS Adsorbate Remazol Brilliant Blue R (RBBR) supplied by Sigma-

Aldrich (M) Sdn. Bhd, Malaysia was used as a model

organic dye for evaluating the adsorption behavior of

the sorbent. The negatively charged dye, RBBR has a

chemical formula of C22H16N2Na2O11S3 with molecular

weight of 626.54 g/mol. The chemical structure of

RBBR is shown in Figure 1. Deionized water supplied

by USF ELGA water treatment system was used to

prepare all the reagents and solutions.

Figure 1. The chemical structure of RBBR

Adsorbent preparation and modifications Natural zeolite, clinoptilolite, sample was obtained from

Malaysia Agricultural Research and Development

Institute (MARDI) which mainly supplied to farmers as

fertilizer to increase crops yield. Preparation of raw

clinoptilolite (R-CL) was done by washing the

clinoptilolite using deionized water to remove all dust or

other impurities and to maintain the natural pH of the

clinoptilolite. Next, the clinoptilolite was dried in an

oven for 24 hour at 373.15 K to remove moisture. In

order to obtain modified form, the R-CL was treated

with Zn(NO3)2 in ethanol at 333 K. The treatment was

carried out by adding 1.0 g R-CL into a Zn(NO3)2 (0.3

g) solution in ethanol (15 mL). The concentration of

Zn(NO3)2 was 0.1 mol/L with 99.9% purity. The

mixture was treated in an oil bath at 333 K for 6 h.

Then, the zeolite sample was separated by filtration,

washed with ethanol to remove excess salt and dried at

353 K for 24 h. The resulting Zn2+-grafted sample is

designated as Zn-CL.

Characterization Fourier transform infrared (FTIR) analysis was applied

to determine the surface functional groups, using FTIR

spectroscope (FTIR-2000, Perkin Elmer), where the

spectra were recorded from 4000 to 450 cm1. The BET

surface area, total pore volume and average pore size of

the R-CL and Zn-CL were measured using ASAP 2020

Micrometrics instrument by BrunauerEmmettTeller

(BET) method.

Adsorption studies Batch equilibrium studies were carried out by adding a

0.5g of R-CL and Zn-CL each into 250 mL Erlenmeyer

flasks containing 200 mL of different initial

concentrations (25-250 mg/L) of dye solution. The

flasks were agitated in an isothermal water-bath shaker

at 120 rpm and different solution temperature (300-350

K) for 24 h until equilibrium was reached. The pH was

adjusted by adding a few drops of diluted 0.1M NaOH

or 0.1M HCl and was measured using a pH meter

(Model Delta 320, Mettler Toledo, Switzerland). The

dye concentrations before and after treatment were

measured using UV-Visible spectrophotometer (Model

Shimadzu UV-1800, Japan) at 590 nm. The amount of

equilibrium adsorption, qe (mg/g), was calculated by:

qe = Co Ce

W (1)

where Co and Ce (mg/L) are the liquid-phase

concentrations of RBBR at initial and at equilibrium,

respectively. V is the volume of the solution (L) and W

is the mass of dry adsorbent used (g).

Batch kinetic studies The procedure of kinetic adsorption tests was identical

to that of batch equilibrium tests, however the aqueous

samples were taken at present time intervals. The

concentrations of RBBR were similarly measures. The

RBBR uptake at any time, qt (mg/g), was calculated by:

Combustion rate: Burning time is obtained by

observing the mass changes recorded on mechanical

balance and also by using stop watch. It is the time for

the biomass combustion to be completed. With known

amount of total burnt briquette and burning time,

average combustion rate can be calculated using the

following formula [12].

= ( )

(2)

where Ct (mg/L) is the liquid-phase concentration of

RBBR at any time, t (h).

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RESULTS AND DISCUSSION Characterization FTIR spectra of R-CL and Zn-CL are shown in Figure

2. The characteristic infrared signals for SiOAl

asymme