Rjeas Research Journal in Engineering and Applied Sciences 1(5) 308-313 Rjeas
© Emerging Academy Resources (2012) (ISSN: 2276-8467)
www.emergingresource.org
308
REMOVAL OF PB
2+
AND CD
2+
IONS FROM WASTEWATERS USING PALM
KERNEL SHELL CHARCOAL (PKSC)
Emmanuel A. Oluyemi, Adewale F. Adeyemi, and Iyabo O. Olabanji
Department of Chemistry,
Obafemi Awolowo University, Ile-Ife. Nigeria.
Corresponding Author: Emmanuel A. Oluyemi
___________________________________________________________________________
ABSTRACT
The use of locally made adsorbent for heavy metal removal in industrial setting is becoming increasingly
popular due to its low cost and effectiveness. This study aimed at the removal of Pb
2+
and Cd
2+
ions from
wastewaters using Palm Kernel Shell Charcoal (PKSC). The influence of several operating parameters such as
the effects of adsorbent dose, time of contact of adsorbate with adsorbent, and agitation speed were
investigated. Equilibrium modeling for maximum efficiency was carried out using the Langmuir and Freundlich
adsorption isotherms. The results showed that the uptake capacity of the PKSC as adsorbent depends largely on
dosage, shaking time and agitation speed. The removal efficiency was high. The optimum PKSC dose for
cadmium and lead ions was 2.0 g/25mL of solution and the optimum shaking time were 45 and 50 min for
cadmium and lead ions respectively. No equilibrium was reached for both ions with respect to agitation speed.
The Freundlich adsorption model described well the sorption equilibrium of cadmium (II) ions and lead (II) ions
on the PKSC in the studied conditions. Additionally, the monolayer capacity, q
m
, less than 1 in all the cases
indicated that PKSC as adsorbent would be effective when the initial concentrations of the ions are low. These
results show that, agricultural waste could be use as cheap and effective tool in the treatment of polluted water
close to mining site or pollution that may occur due to industrial effluents.
©Emerging Academy Resources
KEYWORDS: Adsorbent, Heavy Metals, Palm Kernel, Adsorption Isotherms, Wastewaters.
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INTRODUCTION
Excessive release of heavy metals into the
environment due to industrialization and urbanization
has posed a great problem worldwide. Unlike
organic pollutants, whose majorities are susceptible
to biological degradation, heavy metal ions do not
degrade into harmless end products (Gupta et al.,
2001). The presence of heavy metal ions is a major
concern due to their toxicity to many life forms.
Heavy metal contamination exists in effluents of
many industries, such as paint, metal plating, mining
operations, tanneries, radiator manufacturing,
smelting, alloy industries, etc (Malakootian et al.,
2009; Nasim et al., 2004). Chronic exposure to high
amount of lead and cadmium can result in various
damages to body systems. Moreover, high blood
pressure, anaemia, lead poisoning coma and death
can be considered among the most substantial
consequences of exposure to these heavy metals
(PCS, 2001; Malakootian et al., 2009).
A number of methods for the removal of heavy
metals from aqueous solutions are available,
including microorganisms’ treatment, natural zeolite,
calcinated phosphate, cocoa shell, coffee residue,
sheep hoofs and fresh water plants (Semra et al.,
2004; Erdem et al. 2004; Aklil et al., 2004; Meunier
et al, 2004; Boonamnuayvitaya et al. 2004; Rafika et
al., 2009 and Shama et al.,2010). It is known that
adsorption is one of the most efficient methods for
the removal of heavy metals from wastewater.
Activated carbon is the most widely used adsorbent
due to its excellent adsorption capability for heavy
metals. However, the use of these methods is often
limited due to the high cost, which makes them
unaffordable for the needs of developing countries.
Many reports have been published on the low-cost
adsorbents for heavy metals from aqueous solutions
(Bailey et al.1999: Babel and Tonni 2003). The need
for safe and economical methods for the elimination
of heavy metals from contaminated waters has
necessitated research interest towards the production
of low cost alternatives to commercially available
activated carbon.
Natural biopolymers are industrially attractive
because of their capability of lowering transition
metal ions concentrations to part per billion. Natural
materials that are available in large quantities or
certain waste from agricultural operations may have
potential to be used as low cost adsorbents, as they
represent unused resources widely available and are
environmentally friendly (Deans and Dixon, 1992).