© by PSP Volume 23 – No 12a. 2014 Fresenius Environmental Bulletin
3222
INVESTIGATION OF ADSORPTION PARAMETER EFFECTS ON
THE REMOVAL OF CYANIDE IN WATER USING CLINOPTILOLITE
Ayla Bilgin
1,
*, Erdoğan Hasdemir
2
and Atilla Murathan
3
1
Artvin Coruh University, Engineering Faculty, Department of Environmental Engineering, Artvin, Turkey
2
Gazi University, Faculty of Sciences, Department of Chemistry, Ankara, Turkey
3
Gazi University, Engineering Faculty, Department of Chemical Engineering, Ankara, Turkey
Presented at the 17
th
International Symposium on Environmental Pollution and its
Impact on Life in the Mediterranean Region (MESAEP), September 28 - October 01, 2013, Istanbul, Turkey
ABSTRACT
Natural zeolite clinoptilolite is mined commercially in
many areas of Turkey. The current study investigated the
removal performance of clinoptilolite from the Manisa-
Gördes area on cyanide, which is present in water. Clinop-
tilolite was broken into pieces, and separated into two par-
ticle sizes, -0.40/+0.32 mm and -0.71/+0.40 mm, and the
effects of three different initial cyanide concentrations and
three different flow rates on cyanide removal capacity were
tested. According to batch experimental results, approxi-
mately 60% cyanide was removed from the water.
KEYWORDS: Clinoptilolite, cyanide, removal, batch, and dynam-
ic system
1. INTRODUCTION
The applications of natural clinoptilolite include pol-
lution control, agriculture, aquaculture, mining, and met-
allurgy [1]. Clinoptilolite makes use of one or more physi-
cal and chemical properties: ion-exchange, adsorption and
related molecular sieve properties, and composition. In
practice, however, the ion-exchange depends on, notably,
the nature of the cations species (size, charge, etc...), the
temperature, the concentration of the cation species in
solution, contact time, flow rate of solution, and the struc-
tural characteristics of clinoptilolite (rate of Si:Al). Its
cation selectivity has been reported as: Cs
+
>Rb
+
>NH
+
4
>
Ba
2+
>Sr
2+
>Na
+
>Ca
2+
>Fe
2+
>Al
3+
>Mg
2+
>Li
+
[2] and Pb
2
>
NH
+
4
> Cu
2+
,Cd
2+
> Zn
2+
,Co
2+
>Ni
2+
>Hg
2+
[3].
Clinoptilolite has been applied to gas cleaning [4],
wastewater cleaning [5], animal health [6], gas separation
[7,8], deodorization [4], cleaning of radioactivity wastes
[9], cation exchange [11-16], selectivity of some metal
ions and heavy metals [17-22], and ammonia adsorption,
* Corresponding author
in particular [4,10]. In addition to adsorption being an
efficient method of removing polluters from water, its being
an environment-free, cheap and easily provided method
certifies its economy [34-37]. All these methods have
some disadvantages such as incomplete removal of ioniza-
tion, low level of efficiency in annihilating hyper-pollution,
high energy consumption, and recleansing of toxic mud and
waste water. Adsorption method is, however, one of the
mostly-preferred methods as it is cheap and abundant,
quick, having recurrence and is easily applicable [34].
The availability and low cost of natural zeolites has
stimulated further research for new applications. A new
field is the anion adsorption. A few papers have been
published on zeolite modification by the adsorption of
quaternary ammonium salts-surfactants [23-25]. Another
more common method of natural zeolite modification is
their transformation into the H
+
-form [26, 27]. This modi-
fication method and other techniques are widely used for
various purposes [28-33]. Natural zeolites do not use for
anions without previous modification and especially cya-
nide ion. The removal of cyanide from groundwater and
contaminated water has become a very important envi-
ronmental issue since cyanide compounds are known to
be toxic to man and other organisms.
The current study aims to reveal the cyanide removal
process from synthetic solutions in natural clinoptilolite
mineral without pre-treatment, and determines their max-
imum capacity. The influence of the particle size, the
concentration of cyanide solutions and flow rates are also
discussed.
2. MATERIALS AND METHODS
2.1 Materials
Natural clinoptilolite was received from the Manisa-
Gördes area in Turkey and it was ground in a vibrating
ball mill to obtain smaller particles. Different particle
sizes were separated by sieving and the -0.40/+0.32 mm
and -0.71/+0.40 mm particle size was selected for the
experiments. Table 1 shows the composition of clinoptilo-