Journal of Water Resource and Protection, 2013, 5, 18-27
http://dx.doi.org/10.4236/jwarp.2013.57A004 Published Online July 2013 (http://www.scirp.org/journal/jwarp)
A Study on Zeolite Performance in Waste Treating
Ponds for Treatment of Palm Oil Mill Effluent
M. Halim Shah Ismail*, Shazryenna Dalang, Syafiie Syam, Shamsul Izhar
Department of Chemical and Environmental Engineering, Faculty of Engineering,
Universiti Putra Malaysia, Serdang, Malaysia
Received April 27, 2013; revised May 29, 2013; accepted July 4, 2013
Copyright © 2013 M. Halim Shah Ismail et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Oil palm currently occupies the largest acreage of farm land in Malaysia. In 2011, the produ ction of palm oil in Malay-
sia was recorded as 19.8 million tons which has led to a huge amount of wastewater known as palm oil mill effluent
(POME). This work focuses on the ponding system which acts as wastewater treatment plant in order to treat POME.
The conventional ponding system applied in mills consists of a series of seven ponds. The maintenance costs of the
pond are expensive thus study of alternative methods is needed. POME treatment using zeolite shows a potential to
overcome the problem. Samples collected from selected ponds are tested and analyzed using water analyzer method.
Result from adsorption by zeolite shows a significant reduction of COD, BOD, Fe, Zn, Mn and turbidity. This shows
that zeolite is highly potential to be applied as adsorbent in the POME treatment plants. The results here may lead to
lower maintenance cost, lower quantity of treatment po nds and lesser land occupied for the treatment of POME in Ma-
laysia.
Keywords: Palm Oil Mill Effluent (POME); Zeolite; Wastewater Treatment
1. Introduction
Palm oil is one of the world’s most rapidly expanding
equatorial crops. Indonesia and Malaysia are the two
largest oil palm producing countries and is rich with nu-
merous endemic, forest-dwelling species. Malaysia has a
tropical climate and is prosperous in natural resources.
Oil palm currently occupies the largest acreage of farmed
land in Malaysia [1]. Over the recent years, there has
been a growing concern about the discharge of oil-con-
taining industrial wastewater into the ecosystem. Palm oil
processing in Malaysia annually produces a huge amount
of wastewater known as palm oil mill effluent (POME).
POME is a viscous brown liquid with fine suspended
solids at pH ranging between 4 and 5 [2]. Characteristics
of POME are tabulated in Table 1. In the process of
palm oil milling, POME is generated through steriliza-
tion of fresh oil palm fruit bunches, clarification of palm
oil and effluent from hydrocyclone operations [3]. It is
estimated that about 0.5 - 0.75 tons of POME are dis-
charged from the mill for every ton of fresh fruit bunch
(FFB) [4]. In Malaysia about 53 million m3 POME is
being produced every year based on palm oil production
since 2005. Therefore, the challenge of converting POME
into an env ironmental friendly waste requires an efficient
treatment and effective disposal.
Ponding systems are easy operating systems but they
occupy a vast amount of land mass, relatively long hy-
draulic retention time (45 - 60 days) and bad odor. More-
over, it is difficult to maintain the liquor distribution and
biogas collection which leads to harmful effect on the
environment [5,6]. Another major disadvantage of using
ponding system is the formation of scum and solids that
tend to build up at the bottom of the pond. The sludge
and scum will clump together inside the pond lowering
the treatment efficiency. Therefore, the system requires
regular desludging process by either using submersible
pumps or excavators. Since the POME treatment applied
at mills consists of seven ponds, th e maintenance cost for
all the ponds is very costly. Due to these facts, palm oil
mills face the challenge of balancing the environmental
protection, its economic viability and sustainable devel-
opment. There is an urgent necessity to find an approach
to preserve the environment while keeping the economy
growing.
*Corresponding a uthor.
C
opyright © 2013 SciRes. JWARP

M. H. S. ISMAIL ET AL. 19
Table 1. Characteristic of untreated POME [15].
Parameter Concentration*
pH 4.7
Temperature 80 - 90
BOD 3-day, 30˚C 25,000
COD 50,000
Total Solids 40,500
Suspended Solids 18,000
Total Volatile Solids 34,000
Ammoniacal-Nitrogen 35
Total Nitrogen 750
Phosphorus 18
Potassium 2,270
Magnesium 615
Calcium 439
Boron 7.6
Iron 46.5
Manganese 2.0
Copper 0.89
Zinc 2.3
*All units are in mg/L except pH and Temperature (˚C).
Zeolites are safe, naturally occurring crystalline alu-
minosilicate that have a three-dimensional structure;
aluminum, silicon and oxygen which are arranged in a
regular structure of [SiO4]- and [AlO4]-tetrahedral units
that form a framework with small pores (also called tun-
nels, channels or cavities) of about 0.1 - 2 nm diameter
running through th e material [7]. In these small channels,
solid, liquid and gaseous substances can be trapped [8].
High ion exchange capacity, the molecular sieve proper-
ties and the relatively high surface area [9,10] make zeo-
lite a promising adsorbent media for treating effluent
with different suspended solids [11]. Zeolites have wide
application as gas and odor filter, as a part of animal feed,
and as ammonia removers from different wastewaters
[12,13]. The metallic ions sorbent behavior of natural
zeolite has been also stud ied by several researches, and it
has been recognized as a promising sorbent for heavy
metals [14]. Despite these various researches that have
shown the feasibility of its application for removal of
heavy metals from aqueous solution, limited studies have
been carried out on COD, BOD and turbidity removal in
POME treatment. Thus, this study will apply the opti-
mum condition for zeolite to treat POME in order to de-
termine the performance of zeolite for POME treatment
at different ponds. A successful result could minimize the
quantity of treatment ponds in palm oil mill in order to
minimize the annual operation cost and the area of land
used.
2. Materials and Methods
2.1. Sources of POME Samples
This study was conducted at one of palm oil mill in Ma-
laysia. This mill has the capacity to process 30 ton/h of
FFB. Since the factory operates continuously for 24 hours,
it is capable to process 720 ton/d of FFB. Roughly, the
mill will produce 360 ton/d of POME. POME treatment
applied by the mill was the ponding system which con-
sists of several ponds and ends up with wastewater treat-
ment plant which is an extended aeration type before dis-
charging the effluent into the river. The ponds are sepa-
rated by their function as in Table 2. The percentage of
removal is further studied to identify if this laboratory
scale treatment can b e applied. Natu ral zeolite (clino ptilo-
lite) that was used in th is study was supplied from Slova-
kia. Prior to the experiment, the zeolite was crushed and
passed throug h a No. 20 sieves before it was washed with
distilled water and dried in an oven at 12 0 ˚C for 18 h.
2.2. POME Analysis
The analysis of POME characterization in this study is
limited to COD, BOD, heavy metals and turbidity only.
The POME is characterized before and after the adsorp-
tion by zeolite.
The COD is used as a measure of the oxygen equiva-
lent of the organic matter content of a sample that is sus-
ceptible to oxidation by a strong chemical oxidant. In this
project, the open reflux method of COD analysis is used
as it is suitable for a wide range of waste where a large
sample size is preferred. The procedures for COD analy-
sis consist of apparatus preparation, sample and reagent
preparation and reading method. For apparatus prepara-
tion, this analysis requires the reflux apparatus which
consists of Digital Reactor Block (DRB 200), micro bu-
Table 2. POME treatment ponds.
Sample Real Pond Sample Label
Cooling Pond 1
Mixing Pond 2
Anaerobic 1 Pond 3
Anaerobic 2 Pond 4
Facultative Pond 5
Algae 1 Pond 6
Algae 2 Pond 7

M. H. S. ISMAIL ET AL.
20
rette, pipette, conical flask and culture tubes (16 × 100
mm).
To begin the experiment, 2.5 mL of sample is placed
in the culture tube. 1.5 mL of 0.01167 M potassium di-
chromate digestion solution is added. 3.5 mL sulphuric
acid is carefully added as the formation of acid layer un-
der the sample-digestion solution layer is required. The
culture tubes are tightly cap an d inverted several times to
allow sample to be completely mixed. The culture tubes
are placed in the block digester, preheated to 150˚C and
refluxed for 2 hours behind a protective shield. The cul-
ture tubes are then taken out and cooled to room tem-
perature. The culture tubes caps are removed and 0.05 to
0.10 mL (1 to 2 drops) ferroin indicator is added. The
samples are titrated with standardized 0.10 M FAS while
stirred rapidly. Reading is taken when the end point is
reached. The endpoint is a sharp color that changed from
blue-green to reddish brown, although the blue-green
may reappear within minutes. The blank samples were
prepared in the same manner.
The COD value of the sample was calculated using the
following equation:

27
KCrO
FAS FAS
0.1COD
VAB
M 
sample
8000M
VV

where MFAS= molarity of FAS solution (M), VK2CrO7 =
volume 0.0167 M K2CrO7 (mL), VFAS = volume FAS
used in titration (mL), A = mL FAS used for blank, B =
mL FAS used for sample, M = molarity of FAS.
The procedures fo r BOD analysis consist of incubatio n
bottles –300 ml bottles, incubator–thermostatically con-
trolled at 20˚C ± 1˚C, burette, pipette 2 ml, measuring
cylinder –100 ml and 200 ml, aluminum foil and stan-
dard laboratory glassware. There are 3 parts in measuring
BOD; sample pre-treatment, preparation of dilution water
and the measurement of BOD. For sample pre-treatment,
pH for all the samples is checked. Sample with pH not
between 6.0 and 8.0 is adjusted to pH to 7.0 to 7.2 using
H2SO4 solution. NaOH solution is used to adjust the
sample with pH lower than 6.0. The NaOH should be in
such strength that the quantity of reagent does not dilute
the sample by more than 0.5%. The pH of dilution water
should not be affected by the lowest sample dilution.
In preparing dilution water, a desired working volume
of source water is transferred to a suitably sized bottle.
The dissolve oxygen concentration is checked so at least
7.5 mg/L is existed before it can be used for BOD tests.
DO is added by shaking or by aerating it with or-
ganic-free filtered air. Finally 1mL each of phosphate
buffer, magnesium sulphate (MgSO4), calcium chloride
(CaCl2) and ferrous chloride (FeCl3) solutions per liter of
water is added. Dilution of sample is also required. In
this experiment, the dilution is based on 1 to 5% for raw
and settled wastewater. To measure BOD, ten BOD 300
mL bottles are prepared, eight for POME samples and
two for blank samples. All bottles are labelled accord-
ingly to indicate day-0 and day-5 to avoid confusion. 1
mL of diluted sample is added into the sample bottles
and 1mL of deionised water is added into the blank sam-
ples. Dilution water is added until it reached the neck of
the bottles for complete filling. The sample is then mixed
by inverted the bottles several times. The day-5 bottles
are wrapped with aluminium foil and are incubated for 5
days at 20˚C.
The DO is determined directly for day-0 samples by
adding 1mL of manganese sulphate (MnSO4) solution
followed by 1 mL of iodine-azide reagent. The bottles
are then sealed and inverted a few times to allow mixing.
1mL of concentrated H2SO4 solution is added after the
suspension has fully settled. Again, the bottles are sealed
and mixed by inverting several times until dissolution
complete. 200 mL of the sample are taken out and ti-
trated with sodium thiosulphate solution. Few drops of
starch indicator are added and titrated until the samples
are colorless. This procedure is repeated for the day-5
sample and blank bottle after the five days of incubatio n.
The BOD is determined by the formula below:



12300
BOD mgLsample ml
DD

where D1 = DO of diluted sample immediately after
preparation (mg/L), D2 = DO of diluted sample after 5
days of incubation at 20˚C (mg/L).
The heavy metal analysis is examined using the Ato-
mic Absorption Spectroscopy (Shimadzu). Substance
must first be dissolved in a liquid, dried and then atom-
ized to vaporize the substance into gas atoms. Sample is
prepared by adding 5% of nitric acid and refluxed at
95˚C for 15 minutes. Then, the sample is filtered with
0.45 µm filter paper. The standard solution is prepared
for Zn, Fe and Mn and based on the permissible limit
concentration.
The turbidity is analyzed by 2100N and AN Turbidity
Meter, which adopted the Nephelometry method. The
Nephelometry method is the standard method for meas-
uring turbidity because of the method’s sensitivity, preci-
sion, and applicability over a wide range of particle size
and concentration. The POME samples were measured
directly without pretreatment.
3. Results and Discussion
3.1. Characteristics of POME in Ponding System
The parameters analyzed in this study are COD, BOD, Fe,
Zn and Mn and turbidity. The characterization of the
samples collected from the mill by the normal method
without zeolite is summarized in Table 3. Pond 2 con-

M. H. S. ISMAIL ET AL.
JWARP
21
Table 3. Analysis results of POME at Mill Site for ponding system and zeolite adsorption.
Pond Number
Parameter 2 4 5 7
COD (mg/L) 26,880 3264 2112 768
BOD (mg/L) 66,000 420 270 330
pH 4.4 7.5 7.7 8.4
Turbidity (NTU) 4352 100 54.3 13.6
Fe (mg/L) 11.5206 2.9217 0.9479 0.7428
Mn (mg/L) 1.7832 0.3226 0.34495 0.2616
Zn (mg/L) 0.7456 0.5453 0.1681 0.1221
tains higher COD concentration (26880 mg/L) as com-
pared to Pond 4, Pond 5 and Pond 7 where COD concen-
trations are 3264 mg/L, 2112 mg/L and 768 mg/L, re-
spectively. POME characteristics in Table 3 clearly
shows that Pond 2 h as the h ighest va lue of all parameters
due to the presence of high degradable organic matter,
which most probably caused by the presence of unrecov-
ered palm oil.
The BOD concentration at Pond 2 is 66,000 mg/L,
while Pond 4, Pond 5 and Pond 7 has the BOD concen-
trations of 420 mg/L, 270 mg/L and 330 mg/L, respect-
tively. Similar to COD concentration, Pond 2 contains
less dissolve oxygen as it has higher BOD concentration
compared to other treatment ponds.
The turbidity of Pond 2 is 4352 NTU, which indicates
poor aesthetic characteristic. The turbidity level for
wastewater should comply with the turbidity for drinking
water, which should not exceed 1000 NTU. Pond 2
shows acidic behavior of pH 4.4 and this is comparable
to Ma et al. on characterization of POME [15]. Normally
palm oil mill wastewater is low in pH because of the or-
ganic acids produced during the fermentation process.
However, throughout the POME treatment by ponding
system, the pH at Pond 4, Pond 5 and Pond 7 show alka-
line behavior with pH of 7.5, 7.7 and 8.4, respectively.
POME samples were considered a non-toxic wastewater
as no chemical was added in the oil extraction process.
However, it is identified as a major source of aquatic
pollution caused by depleting dissolved oxygen when
discharged untreated into the w ater bodies [16].
Figure 1. COD concentration after POME was treatedwith
and without zeolite as adsorbent.
monly on anaerobic, aerobic and facultative processes.
This is evident by the degradation of COD concentration
at Pond 2 to Pond 7, where the COD concentration of
Pond 2, Pond 4, Pond 5 and Pond 7 is 26 ,680 mg/L, 3264
mg/L, 2112 mg/L, and 768 mg/L respectively.
The treatment of POME with zeolite in Figure 1
shows the COD concentration that all samples are de-
creasing. The COD concentration at Pond 2 reduced to
17,280 mg/L, lower than that without zeolite. The COD
concentration is also reduced at Pond 4, Pond 5 and Pond
7 to 1920 mg/L, 960 mg/L, and 576 mg/L, respectively.
The acceptable conditions for discharge of industrial ef-
fluent containing chemical oxygen demand for specific
trade or industry sector is 200 mg/L as the discharge
limit. Therefore, to comply with the regulation, but the
mill has abio-polishing plant where the COD concentra-
tion can fu r t h er be reduced.
3.2. COD Analysis
Figure 1 illustrates the COD concentrations of normal
POME treatment (without zeolite) and treatment with
zeolite. The figure clearly indicates both COD concentra-
tion is degrading from Pond 2 to Pond 7. According to
Sethupathi [17], the organic substance of POME is gen-
erally biodegradable; therefore treatment by biodegrade-
able process could be suitable, which are based com-
Figure 1 (bar graph) indicates that zeo lite has different
capacity of COD sorption at different type of POME
characteristic. The highest removal percentage of COD
concentration is found at Pond 5 (54.6%). Pond 5 is a
facultative pond where according to Gray [18], faculta-

M. H. S. ISMAIL ET AL.
22
tive ponds are characterized by having an upper aerobic
and a lower anaerobic zone with active purification oc-
curring in both.
The sorption capacity of zeolite at Pond 4 is almost
similar as the COD concentration reduction at Pond 5
(41.2%). This identifies that zeolite can p erform better at
condition where anaerobic and aerobic condition exists.
The other removal percentage of COD concentration is at
Pond 7 (25%) and Pond 2 (35.7%). Microwave inciner-
ated rice husk ash (MIRHA) have been reported as an
adsorbent in POME treatment, but the capacity of COD
reduction for MIRHA is 41%. This indicates the COD
sorption capacity of zeolite is better than MIRHA.
3.3. BOD Analysis
Figure 2 indicates the BOD concentrations after POME
was treated without (normal) and with zeolites. Pond 2
which contains the raw POME after a cooling process
has the highest concentration of BOD (66000 mg/L)
when zeolite was not used. High concentration of BOD
indicates the raw POME is mixed with the digested
POME and the BOD concentration signifies less concen-
tration of dissolve oxygen. However, the BOD concen-
tration the present study is three times higher than the
sited BOD concentration cited in literature [15] where
BOD concentration of typical POME is 25,000 mg/L.
This is maybe due to the desludging activity at Pond 3
(Aerobic 1), as a result from the accumulation of organic
substances at Pond 2. Higher BOD concentration shows
that there is a high competition for the dissolve oxygen
by the suspended, dissolved substances and micro organ-
ism in the POME. The concentrations of BOD did not
change much after Pond 2 with Pond 4, 5 and 7 obtained
420, 270 and 330 mg/L, respectively. The organic sub-
stance of POME is generally biodegradable; therefore
treatment by biodegradable process could be suitable,
which are based commonly on anaerobic, aerobic and
facultative processes. Figure 2 demonstrates the concen-
tration of BOD treated with zeolite at Pond 2. It clearly
shows the reduction of BOD concentration. The BOD
Figure 2. BODconcentration in ponds treated without and
with zeolite as adsorbent.
concentration reduces from 54,000 mg/L (Pond 2), 210
mg/L (Pond 4), 60 mg/L (Pond 5) and 90 mg/L (Pond 7).
This decrement that is lower than treatment without zeo-
lite proves that zeolite has a high capacity of BOD con-
centration adsorption .
Figure 2 (bar graph) demonstrates the percentage of
BOD removal by zeolite. The highest BOD percentage
removal is found at Pond 5, which is 77.8%. Adsorption
at Pond 2 sample is poor as zeolite can only remove
18.2% of the BOD concentration. Pond 4 and Pond 7 has
the percentage of BOD concentration removal of 50%
and 72.73%, respectively. The performance of zeolite as
BOD remover is excellent as it can reduce the BOD con-
centration up to 70% at two different pond, the faculta-
tive pond (Pond 2) and the al gae 2 (P on d 7) .
3.4. Heavy Metal Analysis
The Fe ion concentration after POME is treated without
zeolite is illustrated in Figure 3. Pond 2 has the highest
Fe concentration with 11.52 mg/L. The lowest is at Pond
7, where the concentration is 0.74 mg/L. Pond 4 and 5
contain Fe concentration of 2.92 mg/L and 0.95 mg/L,
respectively. However, when zeolite is used with POME
treatment, the Fe ion concentrations notably dropped to
2.79 mg/L (Pond 2), 0.51 (Pond 4), 0.80 (Pond 5) and
0.03 (Pond 7). Pond 2 has reduction of Fe up to 75%
from its initial concentration. Figure 3 (bar graph) also
depicts the sorption efficiency. Pond 7 showed efficiency
of 96%, followed by Pond 4 (82.5%), Pond 2 (75.8%)
and Pond 5 (16%).
The Zn concentration is shown in Figure 4. When
POME is treated without zeolite, Zn content is less than
1mg/L. The Pond 2, Pond 4, Pond 5 and Pond 7Zn con-
centrations are 0.75 mg/L, 0.55 mg/L, 0.17 mg/L and
0.12 mg/L, respectively. However when POME is treated
with zeolite, the Zn concentration reduced to 0.25 mg/L
(Pond 2), 0.23 (P ond 4), 0.13 (Pond 5) and 0.10 (Pond 7).
Figure 4 (bar graph) depicts the sorption efficiency.
Figure 3. Fe content in ponds tr eated without and with zeo-
lite as adsorbent.

M. H. S. ISMAIL ET AL. 23
Figure 4. Zn content in ponds treated without and with
zeolite as adsorbent.
Pond 2 showed efficiency of 66.7%, followed by Pond 4
(58.2%), Pond 5 (23.5%) and Pond 7 (16.7%).
Figure 5 illustrates the concentration of Mn when
POME is treated without zeolite (normal) and with zeo-
lite. The concentration of Mn is clearly different among
all samples. Sample at Pond 2 have higher amount of Mn
which is 1.78 mg/L. The other ponds are having less than
0.35 mg/L concentration of Mn. Pond 4, Pond 5 and
Pond 7 have Mn concentration of 0.32 mg/L, 0.34 mg/L
and 0.26 mg/L, respectively. However when POME is
treated with zeolite, the Mn concentration reduced to
0.44 mg/L (Pond 2), 0.1 (Pond 4), 0.01 (Pond 5) and 0.10
(Pond 7). Figure 5 (bar graph) depicts the sorption effi-
ciency. Pond 2 showed efficiency of 75.3%, followed by
Pond 4 (68.8%), Pond 5 (97.1%) and Pond 7 (61.5%).
The Mn concentration at Pond 5 can be identified as
trace, since the concentration is only 0.01 mg/L.
According to Shavandi [19], the sorption capacities of
64.6%, 53.6% and 52.4% fo r Fe, Zn and Mn were shown
for natural zeolite, respectively. The study is experi-
mented on first aerobic pond. In this study, when tested
at different type of ponds, the capacity of zeolite to ad-
sorb Fe, Zn and Mn is demonstrated in Figures 3-5. The
highest heavy metal sorption for Fe concentration is
96.5% at Pond 7. The highest heavy metal sorption for
Zn concentration is 66.87% at Pond 2. The highest heavy
metal sorption for Mn concentration is 96.81% at Pond 5.
The performance of Zeolite in heavy metal sorption effi-
ciency is different at different characteristic of treatment
ponds. The highest concentration removal of Fe, Zn and
Mn heavy metal is found at dissimilar po nds.
Consequently the reduction of metallic ions concentra-
tion of Fe, Zn and Mn is considered good as all samples
are fulfilling the standard discharge limit for Fe, Zn and
Mn. This is similar to the studies done by [20] who found
the natural zeolite is a promising adsorbent media that
has a potential application as a metal ion adsorbent and
has gained interest among researchers, particularly due to
its ion exchange, molecular sieve properties and also its
relatively high surface area. The metallic ions sorbent
behavior of natural zeolites has been also stud ied by sev-
eral researches, and it has been recognized as a promis-
ing sorbent for heavy metals [21].
3.5. Turbidity Analysis
The turbidity of all pond samples when POME is treated
without (normal) and with zeolite is illu strated in Figure
6. The highest turbidity value is found at Pond 2, 4352
NTU. This indicates excessive turbidity, or cloudiness
which caused by suspended matter or impurities that in-
terfere with the clarity of the POME. These impurities
may include finely divided inorganic and organic matter,
soluble colored organic compounds. In addition, high
turbidity in wastewater is an indication that the raw sam-
ple contains high amount of dissolved and suspended
particles and ions. Dissimilar to Pond 7, the turbidity at
Pond 7 is low and acceptable as it is the final treatment
pond before the effluent is discharged at the river. The
turbidity at Pond 4 and Pond 5 is 100 NTU and 54.3
NTU, respectively.
After the adsorption process by zeolite, turbidity at
Pond 4, 5 and 7 have reduced to less than 20 NTU of
turbidity, which is 19.5 NTU, 16.7 NTU and 7.4 NTU
respectively. Pond 2 turbidity is measured at 1116.5
NTU after the treatment by zeolite. The ability of zeo lite
Figure 5. Mn content in ponds after treated without and
with zeolite as adsorbent.
Figure 6. Turbidity content in ponds treated without and
with zeolite as adsorbent.

M. H. S. ISMAIL ET AL.
24
to remove turbidity is considered excellent as it can re-
move 80% of turbidity at Pond 4, which is to the most
efficient turbidity removal among all other pond. The
performance of zeolite as a turbidity remover can be
evident by its performance at Pond 2, Pond 5 and Pond 7
where the removal of turbidity is 74.3%, 69.2% and
45.6% respectively. Figure 6 clearly demonstrate the
ability of zeolite to remove reduce turbidity at different
pond of POME treatment.
4. Discussion
Comparative studies are carried out to compare results
from other investigators. Adsorption as a wastewater
treatment process has aroused considerable interest dur-
ing recent years. Commercial activated carbon is re-
garded as the most effective material for controlling the
organic load. However, due to its high cost and about
10% - 15% loss during regeneration, unconventional
adsorbents like fly ash, peat, lignite, bagasse pith, wood,
saw dust, periwinkle shells, etc. have attracted the atten-
tion of several investigations and adsorption characteris-
tics have been widely investigated for the removal of
refractory materials for varying degree of success [22].
Tables 4 and 5 summarize the adsorption process done at
different types of wastewater and the percentage removal
of selected parameters.
Table 4 clearly indicates that the most efficient ad-
sorbent in reducing COD concentration is the avocado
seed carbon (98.0%). Zeolite is the least efficient of COD
concentration removal capacity, 54.5%. The adsorbents
can be categorized into 4 level; percentage remova l up to
80%, percentage removal up to 70%, and percentage
removal up to 60%. Zeolite is the only adsorbent with
sorption capacity of COD concentration below than 60%.
Overall, the COD concentration adsorption efficiency of
different adsorbents was in this order, avocado seed car-
bon> animal horn> fly ash > activated charcoal > brick
kiln > bagasse > wood ash > zeolite.
The efficiency of the adsorbents reducing the BOD
concentration apparently shows the best adsorbent to treat
BOD is the avocado seed carbon (99.2%). This is fol-
lowed by activated charcoal at sugar mill wastewater
(80.4%), bagasse (79%), Zeolite (78%), activated carbon
at textile wastewater (74%) and lastly the wood ash (60%).
All adsorbents have up to 60% capacity of reducing BO D
concentration in different type of wastewater.
Four adsorbents have been studied and presented in
Table 4, which can reduce the turbidity of wastewater.
There are activated charcoal, bagasse, zeolite and wood
ash. The highest turbidity reduction is by activated char-
coal with the efficiency of 82.50%. However, the ability
of bagasse and zeolite is considered comparable since the
removal efficiency is 80.6% and 80.5%, respectively.
The wood ash can only remove turbidity at 54.0% effi-
ciency. There are inadequate research on turbidity re-
moval as much of the study is concerning on color re-
moval than the turbid ity.
Numerous researches have been conducted on metallic
ions sorption ability of natural zeolite on both aqueous
solution and real wastewater as illustrated in Table 5.
Table 4. Comparison of different adsorbent ability.
Adsorbent Type of wastewater Parameter Removal Percent ag e References
Brick Kiln Domestic Wastewater COD 83.2
Fly ash Domestic Wastewater COD 87.8 [25]
Animal Horn Industrial Wastewater COD 95.7 [26]
Avocado Seed Carbon Coffee Processing Wastewater COD BOD 98.2 99.2 [27]
Textile Wastewater COD 80.2
Activated Charcoal BOD 74.0
[28]
Sugar Mill Wastewater COD 85.4
BOD 80.4 [29]
Turbidity 82.5
Sugar Mill Wastewater COD 67.4
Wood Ash BOD 60.0 [29]
Turbidity 54.0
Sugar Mill Wastewater COD 79.0
Bagasse BOD 79.0 [29]
Turbidity 80.6
POME Wastewater COD 54.5
Zeolite BOD 78.0 Current study
Turbidity 80.5

M. H. S. ISMAIL ET AL. 25
Table 5. Comparison of natural zeolites ability for metallic ions removal.
Adsorbent Type of wastewater Metal % Removal Reference
Brazilian Natural Scolecite Wastewater Mn 75.0 [30]
Aqueous solution s Zn 53.8 [31]
Cu 66.3
Cd 37.3
Italian Sedimentary
Clinoptiloite
Pb 74.5
Turkey Natural Clinoptilolities Aqueous solution s Zn 24.0 [32]
Jordan Natural Zeolite Aqueous model solutions Fe 69.1 [33]
Motorway stormwater Zn 10.1
Pb 44.2
Cu 32.4
Cd 6.0
Synthetic solution Zn 41.8
Pb 89.2
New Zealand Mordenite
Cu 53.4
[13]
Aqueous solution s Zn 45.9
Mn 19.8 [34]
Cu 6.1
Acid Amine drainage Zn 67.8
Fe 59.9
Turkey Natural Zeolite
Mn 18.9
[21]
POME (raw) Zn 53.6
Fe 64.6
Slovakian Natural Zeolite
Mn 52.4
[19]
POME Zn 66.9 This study
Pond 2 (Mixing) Fe 75.7
Mn 75.4
Pond 4 (Anaerobic 1) Zn 58.7
Fe 82.4
Mn 68.1
Pond 5 (Facultative) Zn 21.1
Fe 15.9
Mn 96.8
Pond 7 (Algae 2) Zn 19.3
Fe 96.5
Slovakian Natural Zeolite
Mn 60.0

M. H. S. ISMAIL ET AL.
26
The Slovakian zeolite u sed in this study has higher Zn
sorption percentage compared to the majority of tested
zeolites. However, Fe removal percentages of all studied
zeolites are almost in the same range that is less than
70%. In case of Mn, the zeolite used in this study shows
the higher remov al ability than zeoli te from Turkey, while
Brazilian zeolite removed Mn ions more effectively. In
this study case, the sorption capacity of the Slovakian
zeolite to reduce the concentration of Fe, Zn and Mn is
different at different pond. This is maybe due to the dif-
ferent contents of metallic ions in all samples.
Overall, the adsorption process is one of the effective
methods for pollutant removal from the waste effluent
especially heavy metal ions, color, odor and organic pol-
lution [23,24]. The process of adsorption has an edge
over the other methods due to its sludge free clean opera-
tion and low capital intensive nature. Even though, zeo-
lite has less adsorption capacity toward reducing COD
concentration, the other abilities should not be over-
looked. The present study evidenced that zeolite is ex-
cellent for the reduction of BOD concentration and re-
moval sorption of metal and turbidity during POME
treatment.
5. Conclusion
The characterization of POME has been carried out. The
POME at Pond 2 has the highest concentration of all
tested ponds due to the fact that it is the first receiver of
POME. Due to the recent desludging activity at Pond 4
and Pond 5, BOD concentration in Pond 7 was slightly
high. The POME at Pond 2, Pond 4, Pond 5 and Pond 7
has been treated through adsorption process by zeolite.
The adsorption process shows a substantial reduction in
COD, BOD, heavy metals and turbidity. This indicates
the performance of zeolite as adsorbent is promising.Th e
highest concentration removal is at Pond 2, thus applying
zeolite in Pond 2 could result in positive step in reducing
the POME treatment ponds in mills.
REFERENCES
[1] S. Arifand and T. A. Tengku Mohd Ariff, “The Case
Study on the Malaysian Palm Oil,” United Nations Con-
ference on Trade and Development/Economic and Social
Commission for Asia and the Pacific Regional Workshop
on Commodity Export Diversification and Poverty Re-
duction in South and South-East Asia, Bangkok, 3-5 April
2001.
[2] G. D. Najafpour, A. A. LZinatizadeh, A. R. Mohamed, M.
Hasnain Isa, H. Nasrollahzadeh, “High-Rate Anaerobic
Digestion of Palm Oil Mill Effluent in an Upflow An-
aerobic Sludge-Fixed Film Bioreactor,” Process Bio-
chemistry, Vol. 41, No. 2, 2006, pp. 370-379.
doi:10.1016/j.procbio.2005.06.031
[3] R. Borja, C. J. Banks and E. Sánchez, “Anaerobic Treat-
ment of Palm Oil Mill Effluent in a Two-Stage Up-Flow
Anaerobic Sludge Blanket (UASB) Reactor,” Journal of
Biotechnology, Vol. 45, No. 2, 1996, pp. 125-135.
doi:10.1016/0168-1656(95)00154-9
[4] S. Yacob, M. A. Hassan, Y. Shirai, M. Wakisaka and S.
Subash, “Baseline Study of Methane Emission from Open
Digesting Tanks of Palm Oil Mill Effluent Treatment,”
Chemosphere, Vol. 59, No. 11, 2005, pp. 1575-1581.
doi:10.1016/j.chemosphere.2004.11.040
[5] C. O. Onyia, A. M. Uyub, J. C. Akunna, N. A. Norulaini
and A. K. M. Omar, “Increasing the Fertilizer Value of
Palm Oil Mill Sludge: Bioaugmentation in Nitrification.
Sludge Management Entering the Third Millenium,” In-
dustrial, Combined, Water and Wastewater Residues, Vol.
44, 2001, pp. 157-162.
[6] K. K. Chin, S. W. Lee and H. H. Mohammad, “A Study
of Palm Oil Mill Effluent Treatment Using a Pond Sys-
tem,” Water Science and Technology, Vol. 34, No. 1,
1996, pp. 119-123. doi:10.1016/S0273-1223(96)00828-1
[7] A. W. Chester and E. G. Derouane, “Zeolite Characteri-
zation and Catalysis,” Springer, Heidelberg, London,
New York, 2001.
[8] D. Mohan and K. P. Singh, “Single- and Multi-Compo-
nent Adsorption of Cadmium and Zinc Using Activated
Carbon Derived from Bagasse—An Agricultural Waste,”
Water Research, Vol. 36, No. 9, pp. 2304-2318.
doi:10.1016/S0043-1354(01)00447-X
[9] V. J. Inglezakis, M. D. Loizidou and H. P. Grigoropoulou,
“Ion Exchange of Pb2+, Cu2+, Fe3+, and Cr3+ on Natural
Clinoptilolite: Selectivity Determination and Influence of
Acidity on Metal Uptake,” Journal of Colloid and Inter-
face Science, Vol. 261, No. 1, pp. 49-54.
doi:10.1016/S0021-9797(02)00244-8
[10] S. Mohan and R. Gandhimathi, “Removal of Heavy Metal
Ions from Municipal Solid Waste Leachate Using Coal
Fly Ash as An Adsorbent,” Journal of Hazardous Mate-
rials, Vol. 169, No. 1-3, 2009, pp. 351-359.
[11] Z. Milán, E. Sánchez, P. Weiland, R. Borja and A. Marti,
“Influence of Different Natural Zeolite Concentrations on
the Anaerobic Digestion of Piggery Waste,” Bioresource
Technology, Vol. 80, No. 1, 2001, pp. 37-43.
doi:10.1016/S0960-8524(01)00064-5
[12] T. S. Jamil, H. S. Ibrahim, I. H. Abd El-Maksoud, S. T.
El-Wakeel, “Application of Zeolite Prepared from Egyp-
tian Kaolin for Removal of Heavy Metals. I. Optimum
Conditions,” Desalination, Vol. 258, No. 1-3, 2010, pp.
34-40. doi:10.1016/j.desal.2010.03.052
[13] S. K. Pitcher, R. C. T. Slade and N. I. Ward, “Heavy
Metal Removal from Motorway Stormwater Using Zeo-
lites,” Science of The Total Environment, Vol. 334-335,
2004, pp. 161-166. doi:10.1016/j.scitotenv.2004.04.035
[14] T. Motsi, N. A. Rowson and M. J. H. Simmons, “Adsorp-
tion of Heavy Metals from Acid Mine Drainage by Natu-
ral Zeolite,” International Journal of Mineral Processing,
Vol. 92, No. 1-2, 2009, pp. 42-48.
doi:10.1016/j.minpro.2009.02.005
[15] A. N. Ma, “Treatment of Palm Oil Mill Effluent,” In: G.
Singh, K. H. Lim, T. Leng and L. K. David, Ed., Oil
Palm and the Environment: A Malaysian Perspective,

M. H. S. ISMAIL ET AL. 27
Malaysian Oil Palm Growers’ Council, Kuala Lampur,
1999, pp. 113-126.
[16] R. Khalid and W. A. Wan Mustafa, “External Benefits of
Environmental Regulation: Resource Recovery and the
Utilisation of Effluents,” The Environmentalist, Vol. 12,
No. 4, 1992, pp. 277-285. doi:10.1007/BF01267698
[17] S. Sethupathi, “Removal of Residue Oil from Palm Oil
Mill (POME) Using Chitosan,” Universiti Sains Malaysia,
Vol. 41, 2004, pp. 962-964.
[18] N. F. Gray, “Biological of Wastewater Treatment,” Ox-
ford University Press, Oxford, 1992.
[19] M. A. Shavandi, Z. Haddadian, M. H. S. Ismail, N. Ab-
dullah and Z. Z. Abidin, “Removal of Fe(III), Mn(II) and
Zn(II) from Palm Oil Mill Effluent (POME) by Natural
Zeolite,” Journal of the Taiwan Institute of Chemical En-
gineers, Vol. 43, 2012, pp. 750-759.
doi:10.1016/j.jtice.2012.02.014
[20] S. Mohan and R. Gandhimathi, “Removal of Heavy Metal
Ions from Municipal Solid Waste Leachate Using Coal
Fly Ash as An Adsorbent,” Journal of Hazardous Mate-
rials, Vol. 169, No. 1- 3, 2009, pp. 351-359.
[21] E. Erdem, N. Karapinar and R. Donat, “The Removal of
Heavy Metal Cations by Natural Zeolites,” Journal of
Colloid and Interface Science, Vol. 280, No. 2, 2004, pp.
309-314. doi:10.1016/j.jcis.2004.08.028
[22] K. K. Pandey, G. Prasad and V. N. Singh, “Copper Re-
moval from Aqueous Solutions by Fly Ash,” Water Re-
search, Vol. 19, No. 7, 1985, pp. 869-873.
doi:10.1016/0043-1354(85)90145-9
[23] M. Ganji, M. Khosravi and R. Rakhshaei, “Biosorption of
Pb, Cd, Cu and Zn from the Wastewater by Treated
Azollafiliculides with H2O2/MgCl2,” International Jour-
nal of Environmental Science and Technology, Vol. 1, No.
4, 2005, pp. 265-271.
[24] M. B .G. Steinhauser, “Adsorption of Ions onto High
Silica Volcanic Glass,” Applied Radiation and Isotopes,
Vol. 66, No. 1, 2008, pp. 1-8.
doi:10.1016/j.apradiso.2007.07.010
[25] R. Devi and R. P. Dahiya, “Chemical Oxygen Demand
(Cod) Reduction in Domestic Wastewater By Fly Ash
And Brick Kiln Ash,” Water, Air & Soil Pollution, Vol.
174, No. 1-4, 2006, pp. 33-46.
doi:10.1007/s11270-005-9022-9
[26] E. O. Aluyor and O. A. M. Badmus, “COD Removal
from Industrial Wastewater Using Activated Carbon Pre-
pared from Animal Horns,” African Journal of Biotech-
nology,Vol. 7, No. 21, 2008, pp. 3887-3891.
[27] R. Devi, “Innovative Technology of COD and BOD Re-
duction from Coffee Processing Wastewater Using Avo-
cado Seed Carbon (ASC),” Water, Air, & Soil Pollution,
Vol. 207, 2010, pp. 299-306.
doi:10.1007/s11270-009-0137-2
[28] H. Patel and R. T. Vashi, “Treatment of Textile Waste-
waterby Adsorption and Coagulation,” E-Journal of Che-
mistry, Vol. 7, No. 4, 2010, pp. 1468-1476.
doi:10.1155/2010/987620
[29] C. Saxena and S. Madan, “Evaluation of Adsorbents Ef-
ficacy for the Removalof Pollutants from Sugar Mill Ef-
fluent,” ARPN Journal of Agricultural and Biological
Science, Vol. 7, No. 5, 2012, pp. 325-329.
[30] S. M. Dal Bosco, R. S. Jimenez and W. A. Carvalho,
“Removal of Toxic Metals from Wastewater by Brazilian
Natural Scolecite,” Journal of Colloid and Interface Sci-
ence, Vol. 281, No. 2, 2005, pp. 424-431.
doi:10.1016/j.jcis.2004.08.060
[31] A. Langella, M. Pansini, P. Cappelletti, B. D. Gennaro, M.
de’ Gennaro and C. Colella, “NH4+, Cu2+, Zn2+, Cd2+ and
Pb2+ Exchange for Na+ in a Sedimentary Clinopti-Lolite,
North Sardinia, Italy,” Microporous and Mesoporous
Materials, Vol. 37, No. 3, 2000, pp. 337-343.
doi:10.1016/S1387-1811(99)00276-0
[32] C. Semra, “The Removal of Zinc Ions by Natural and
Conditioned Clinoptilolites,” Desalination, Vol. 225, No.
1-3, 2008, pp. 41-57.
[33] M. Al-Anber and Z. A. Al-Anber, “Utilization of Natural
Zeolite as Ion-Exchange and Sorbent Material in the Re-
moval of Iron,” Desalination, Vol. 225, No. 1-3, 2008, pp.
70-81. doi:10.1016/j.desal.2007.07.006
[34] A. Sdiri, T. Higashi, T. Hatta, F. Jamoussi and N. Tase,
“Evaluating the Adsorptive Capacity of Montmorillonitic
and Calcareous Clays on the Removal of Several Heavy
Metals in Aqueous Systems,” Chemical Engineering
Journal, Vol. 172, No. 1, 2011, pp. 37-46.
doi:10.1016/j.cej.2011.05.015