Wheat Germ as Natural Coagulant for Treatment of Palm Oil Mill Effluent (POME)

Abstract

The potential of wheat germ as a natural coagulant for treatment of palm oil mill effluent (POME) was explored. A series of jar test was conducted for the determination of best extraction method for the wheat germ, optimum dosage and optimum pH. The reported parameters were turbidity, TSS, COD and colour. It was found that the wheat germ extracted with 1M NaCl solution (WG-1M) achieved the highest reduction of turbidity, TSS, COD and colour at 99.1%, 95.6%, 61.7% and 67.8% respectively. This was attained at optimum dosage of 12 000 mg/L and an optimum pH of 2. Results showed that the wheat germ can be regarded as a new potential natural coagulant for the treatment of POME.

Full text

April 2014, Volume 5, No.2
International Journal of Chemical and Environmental Engineering
Wheat Germ as Natural Coagulant for Treatment
of Palm Oil Mill Effluent (POME)
Nor Shazwani Daud; Tinia Idaty Mohd Ghazi*; Intan Salwani Ahamad
Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia
UPM Serdang, Selangor, Malaysia
*Corresponding Author E-mail:tinia@upm.edu.my
Abstract:
The potential of wheat germ as a natural coagulant for treatment of palm oil mill effluent (POME) was explored. A series of jar test
was conducted for the determination of best extraction method for the wheat germ, optimum dosage and optimum pH. The reported
parameters were turbidity, TSS, COD and colour. It was found that the wheat germ extracted with 1M NaCl solution (WG-1M)
achieved the highest reduction of turbidity, TSS, COD and colour at 99.1%, 95.6%, 61.7% and 67.8% respectively. This was attained
at optimum dosage of 12 000 mg/L and an optimum pH of 2. Results showed that the wheat germ can be regarded as a new potential
natural coagulant for the treatment of POME.
Keywords: Wheat germ; natural coagulant; extraction method; palm oil mill effluent (POME); jar test.
1. Introduction
Palm oil industry in Malaysia started in the year 1920
with 400 hectares of oil palm cultivated. More cultivation
areas were opened up as direct consequences of crop
diversification policy by government. In 2013, more than
18 million tons of palm oil was exported [1]. Result from
the growth of the palm oil industry, the milling and
refining sectors also increased. Besides the empty fruit
bunches, mesocarp fibers and shell, palm oil mill effluent
(POME) is one of the wastes produced from the
processing of oil palm fresh fruit bunches (FFB) in the
production of palm oil [2]. From every tonne of fresh fruit
bunches being processed, it is estimated that 0.5-0.75 tons
of POME discharged. POME cannot be discharged
directly to the land, as it will adversely affect the soil and
vegetation system. It is also cannot be discharged into the
watercourses directly without treatment as the good
quality of water bodies for aquatic lives will be depleted
and distracted. Since 1980’s ponding system is the most
conventional and applicable method, used in treating
POME in Malaysia. Though the system is cheap in cost
and easy to operate, but it requires large area with long
retention time and difficult to maintain biogas collection, which
produces bad odor and liquor distribution [3]. The application of
coagulation-flocculation process using natural coagulant
was found to be a new alternative for POME treatment
[4]. Chemical coagulant such as Alum (aluminium
sulphate) is commonly used as coagulant in the
coagulation process for water and wastewater treatment.
However the existence of Aluminum could lead to health
problems as aluminum has correlation to Alzheimer’s
disease [5]. From the findings, sporadic studies have been
carried out to replace the function of chemical coagulants
by using natural coagulants originate from natural plants
(moringa oleifera, nirmali seeds, cactus, tannin, dragon
fruit) and animal (chitosan obtained in inverterbrates) [6-
8]. Moringa oleifera (MO) is the most studied coagulant
compared to other plant based coagulants as its history in
water purification was explored at the beginning of 20th
century [9]. Protein was found to be the active component
in the seeds of MO [10] and this cationic protein reacts
through charge neutralization by-being attached to the
negatively charged particles in wastewater for formation
of floc in coagulation.
The extraction of active component from MO can be
improved by using salt solution as an extractant rather
than using distilled water. At the same initial turbidity of
50 NTU of synthetic wastewater, MO extract with salt
solution (MOC-SC) gave percentage turbidity reduction
to be more than 95% at 4 mL/L dosage, where the dosage
used was 7.4 times lower than MO extract with ordinary
distilled water (MOC-DW) with 32mL/L dosage at only
78% turbidity reduction [11].
Meanwhile the use of dragon fruit foliage as natural
coagulant in the treatment of concentrated latex effluent
could lead to removal of turbidity, SS and COD at 99.7%,
88.9% and 94.7% respectively [8]. At pH 6, chitosan was
able to reduce the turbidity, TSS and COD levels of
POME by 99.9%, 99.2% and 60.7% respectively [12]. As
discussed by previous researchers, active coagulating
component from the plants extracts was the protein [13].

Wheat Germ as Natural Coagulant for Treatment of Palm Oil Mill Effluent (POME)
112
Wheat germ is a by-product of the flour milling process.
Compared to other wheat product (such as wheat bran and
wheat flour), the wheat germ contain the highest value of
protein which constitutes about 27%, followed by wheat
bran (14%), wheat flour (13%) and only small portion for
other wheat products [14]. The availability of protein in
the wheat germ (WG) is the factor it is chosen as potential
of natural coagulant in this research project. The aim of
this research is to investigate the effectiveness of wheat
germ (WG) as a potential bio coagulant for the treatment
of POME.
2. Materials and Method
Materials
Wheat germ seeds were purchased locally from Pesimon
Cereal Resources Sdn Bhd. The WG seeds were ground
to fine powder using a laboratory mill. The ground seeds
were sieved through 0.4 mm sieve and 30 g of the
prepared powder was suspended in 1 L of different
solvents such as the distilled water (WG-DW), tap water
(WG-TW) and 0.25, 0.5 and 1M NaCl labeled as WG-
0.25M, WG-0.5M and WG-1M solution, respectively.
The coagulation active component was extracted through
the stirring of the suspension using magnetic stirrer for 10
minutes and filtered through 47 mm filter paper. This
filtered solution is called as extracts. The extract was
stored at 4oC temperature until use.
Raw POME sample was obtained from palm oil mill
located at Dengkil, Selangor at a temperature range from
80-900C before cooled to room temperature for
experimental work. Characteristics of raw POME are
presented in Table I. Raw POME is thick brownish liquid
which slightly acidic and contains large amounts of
solids, high value of biochemical oxygen demand (BOD)
and chemical oxygen demand (COD). It was collected
directly into a thermal resistant plastic container, which
was then labeled and tightly sealed before being
transported into the laboratory. It is then kept at the cold
room at 4 0C to avoid biodegradation process from
microbial activity.
Table 1. Initial Characteristics of Raw POME
Jar Test
Phipps and Bird stirrer jar test apparatus, which comprises
of six-spindle steel paddles together with six beakers were
used in this experiment. This experiment was conducted
at temperature in the range of 25-30oC. Each of the six
beakers was filled with 250 mL of POME. The
suspension was then added with different coagulant
dosage range from 7000 mg/L to 15 000 mg/L and stirred
at 120 rpm for 1 minute as rapid mixing. The speed was
reduced to 35 rpm for 25 minutes as slow mixing. The
suspension was left for 1 hour to settle and the
supernatant was then withdrawn using a pipette for
turbidity, TSS, COD and colour measurement. The pH
was adjusted within the range of 2-12, by using 1M
NaOH or 1M HCl.
Analytical Method
The turbidity and pH was measured using Hach
turbidimeter model 2100N and pH meter (HACH USA)
respectively. The COD was performed through the closed
reflux method using the APHA standard methods of
examination of water and wastewater. With the aid of
vacuum filtration apparatus, the suspended solid (SS) was
determined through gravimetric method while the total
solid was determined through the determination of
material left after the sample had been evaporated and
undergoes subsequent drying in an oven at 103oC to
105oC. The colour was recorded using HACH
spectrophotometer Model DR 2500.
3. Result and Discussion
Effect of Solvents and Dosage on WG Performance
Effect of different solvents in extracting the WG at
different dosage on the coagulation performance was
analyzed. WG acts as primary coagulant at original pH of
POME sample, i.e. 5. From Fig. 1, treatment of POME
with WG-1M achieved the highest removal of turbidity,
which is 97.7% at optimal dosage of 12 000 mg/L. The
dosage was the optimum for WG-1M as no significant
improvement in turbidity removal with further coagulant
addition. WG-0.5M recorded a turbidity reduction at
96.5%, and WG-0.25M at 96.4%.
Figure 1. Effect of different solvents in extracting WG and dosage
on turbidity removal and POME residual turbidity.
Meanwhile, the WG-DW and WG-TW recorded 94.2%
and 92.9% respectively. The residual turbidity recorded at
this dosage was 580 NTU, 897 NTU, 923 NTU, 1505
NTU and 1825 NTU for WG-1M, WG-0.5M, WG-
Parameters
Raw POME
pH
4.78
Turbidity
25 730 NTU
Total suspended solid (TSS)
18 400 mg/L
Total solid (TS)
38 000 mg/L
Chemical Oxygen Demand (COD)
48 000 mg/L
Colour
17 500 Pt Co

Wheat Germ as Natural Coagulant for Treatment of Palm Oil Mill Effluent (POME)
113
0.25M, WG-DW and WG-TW respectively.
Fig. 2 shows the TSS reduction at 93.5%, 92.8%, 89.1%,
87% and 85.8% after the addition of WG-1M, WG-0.5M,
WG-0.25M, WG-DW and WG-TW respectively to
POME suspension. The residual TSS was recorded to be
1194 mg/L, 1326 mg/L, 2005 mg/L, 2393 mg/L and 2609
mg/L respectively. COD reduction was the highest for
WG-1M, which is 55% followed by 52% for WG-0.5M
and 51.7% for WG-0.25M. In addition to that, 48% and
43.3% of the COD reduction was recorded for WG-DW
and WG-TW respectively. This is shown in Fig. 3. The
residual COD recorded was 21 600 mg/L, 23040 mg/L,
23200 mg/L, 24960 mg/L and 27200 mg/L for WG-1M,
WG-0.5M, WG-0.25M, WG-DW and WG-TW
respectively.
Figure 2. Effect of different solvents in extracting WG and dosage
on TSS reduction and POME residual TSS.
COD reduction and POME residual COD.
As can be seen in Fig. 4, the application of WG-1M into
POME suspension obtained the highest color reduction of
65.2%. This was followed by WG-0.5M with 64.3% and
WG-0.25M with 62.8%.
Meanwhile, WG-DW and WG-TW recorded percentage
of colour reduction at 57.4% and 57.1% respectively. The
residual colour recorded was 6086 Pt Co, 6255 Pt Co,
6503 Pt Co, 7457 Pt Co and 7516 Pt Co for WG-1M,
WG-0.5M, WG-0.25M, WG-DW and WG-TW
respectively.
Figure 4. Effect of different solvents in extracting WG and dosage
on colour reduction and POME residual colour.
The efficiency in coagulation performance is increased
with the application of salt as an extraction method for the
WG and the higher the concentration of NaCl, the better
the coagulation performance. This result is similar to the
result obtained by Okuda et al. [10], where the dosage of
moringa oleifera extracted with 1M NaCl solution was
32 mL/L which is 7.4 times lower as compared to those
extracted with distilled water (4 mL/L). With salt
solution, moringa oleifera coagulate more than 95% of 50
NTU initial kaolin turbidity, while moringa oleifera
extracted with distilled water could only coagulate 78% at
the same initial kaolin turbidity. The result was also
similarly obtained by the work done by Sarpong et al.
[15], where the use of salt solution as solvent in extracting
the active component from moringa oleifera lead to
higher turbidity removal (94%), compared with those
without salt solution (54%) at the same coagulant dosage.
This phenomenon could be explained due to existence of
protein in the WG [14] as protein is said by many
researchers to be an important element in promoting
coagulation [9]. The solubility of protein in water due to
formation of hydrogen bond between amino acids and
water molecules as shown in Fig. 5.
Figure 5. Formation of hydrogen bond between amino acids and
water molecules [16]
At the same time, there is also attractive force between
individual protein molecules through formation of
hydrogen bond. Such forces could lead to aggregation of
protein and less solubility in water molecules. This

Wheat Germ as Natural Coagulant for Treatment of Palm Oil Mill Effluent (POME)
114
interaction can be seen in Fig. 6. As salt add to the
solution, the solubility of protein in water increases [10].
Since NaCl used in this research is a strong electrolyte,
which completely dissociate into Na+ and Cl- ion in water,
this additional ion will shield ionic charge at protein’s
surface and decreases the attractive forces which prevent
aggregation between protein molecules and protein
solubility in water could be promoted.
Figure 6. Hydrogen bond between protein molecules [16]
The higher level of protein soluble in the coagulation
solution (due to salt influence) resulted in better
coagulation performance. Since the operating pH of
POME is in acidic condition (i.e. 5), the amino groups in
the protein were being protonated. Fig. 7 shows the
protonation of amino acid in the acidic condition. Since
particles in POME is negatively in charge [6], the
protonated amino acid in wheat germ is attracted to
negatively charged particles, and this will promotes
coagulation as these particles bind to each other and
growth in size to form a floc. As a result, larger particle or
floc become heavy and settle to the bottom.
Figure 7. Protonation of amino acid in acidic condition [16]
Effect of POME pH on WG performance
The optimum pH of the treatment system was obtained
through the study of the effect of pH on WG-1M
performance. This study is important as the surface
charge of the coagulants and stabilization of the
suspension is affected by the pH of POME suspension.
The pH of POME was adjusted from pH 2 to pH 12. WG-
1M was used as the best extraction method with an
optimal dosage of 12 000mg/L, underwent 120 rpm rapid
mixing, 35 rpm slow mixing, 25 minutes mixing time and
1 hour settling time. Fig. 8 shows the same trend for all
parameter reduction, which is higher at acidic and lower
in alkaline conditions.
Figure 8. Effect of POME pH on all parameters
Good coagulation performance was traced at pH 2,3,4,
and 5; of these, pH 2 is the optimum. The reduction of
turbidity, TSS, COD, and colour at pH 2 were recorded to
be 99.1%, 95.6%, 61.7% and 67.8%, respectively.
Meanwhile, pH 11 shows the lowest coagulation
performance with only 54.9%, 33.7%, 26.7% and 43%
reduction of turbidity, TSS, COD and colour respectively.
This result is similar to the work carried out by Abu
Hassan et al. [6], where the optimum pH was at acidic pH
solution, i.e. 6 with the removal of turbidity, TSS and
COD reported to be 99.9%, 99.15% and 60.73%,
respectively for the treatment of POME using chitosan.
Other work done by Bhatia et al. [17], also obtained the
optimum pH at acidic condition i.e. 5 with the removal in
suspended solids and the COD reduction was 95% and
52.2%, respectively by using moringa oleifera.
This may be due to the positive charges of amino acid in
the acidic solution while, negative at basic solution. These
negatively charged amino acids repel the negatively
charged particles in the wastewater such as POME and
thus, coagulation process become poorer at basic
condition. The structure of amino acid in basic solution is
represented in Fig. 9.
Figure 9. Structure of amino acid in basic solution [16]
4. Conclusion
Wheat germ extracted with 1M NaCl solution (WG-1M)
recorded the highest removal of turbidity, TSS, COD and
colour with optimum dosage of 12 000 mg/L and at
optimum pH of 2. The removal of turbidity, TSS, COD
and colour at this optimum condition were 99.1%, 95.6%,
61.7% and 67.8%, respectively. This significant finding
would be a potential new development in POME
treatment with natural and biodegradable coagulant. It is
recommended that wheat germ be applied to other types
of wastewater treatment in the future work.

Wheat Germ as Natural Coagulant for Treatment of Palm Oil Mill Effluent (POME)
115
ACKNOWLEDGMENT
The authors would like to acknowledge the Department of
Chemical and Environmental Engineering, Universiti
Putra Malaysia for providing facilities and technical
support, and Seri Ulu Langat Palm Oil Mill Sdn. Bhd. for
providing the POME samples.
REFERENCES
[1] Economics and Industry Development Division. “Export of palm
oil by port 2013 (tonnes),” Malaysian Palm Oil Board,
2013,http://bepi.mpob.gov.my/index.php/statistics/export/121-
export-2013/627-palm-oil-export-by-major-ports-2013.html
(accessed 16 Feb. 2014).
[2] Er, A.C., Md. Nor, A. R., & Rostam, K. Palm oil milling wastes
and sustainable development. American Journal of Applied
Sciences, (2011). 8: 436-440.
[3] Rupani, P. F., Singh, R. P., Ibrahim, H., & Esa, N. Review of
current palm oil mill effluent (pome) treatment methods:
vermicomposting as a sustainable practice. World Applied
Sciences Journal, (2010). 11: 70-81.
[4] Othman, Z., Bhatia, S., & Ahmad, A.L. Influence of the
settleability parameters for palm oil mill effluent (POME)
pretreatment by using moringa oleifera seeds as an environmental
friendly coagulant. Journal of Materials Science and Engineering,
(2011). 5: 332-340.
[5] Flaten, T. P., Aluminium as a risk factor in alzheimer’s disease,
with emphasis on drinking water. Brain Research Bulletin, (2001).
55: 187–196.
[6] Abu Hassan, M. A., & Puteh, M. H. Pre-treatment of palm oil mill
effluent (pome): a comparison study using chitosan and alum.
Malaysian Journal of Civil Engineering, (2007). 19: 128-141.
[7] Chen, C. Y., & Chung, Y. C. Comparison of acid-soluble and
water-soluble chitosan as coagulants in removing bentonite
suspensions. Water Air Soil Pollution, (2011). 217: 603–610.
[8] Idris, J., Som, A. M., Musa, M., Ku Hamid, K. H., Husen, R., &
Muhd Rodhi, M. N. Dragon fruit foliage plant-based coagulant for
treatment of concentrated latex effluent: comparison of treatment
with ferric sulfate. Journal of Chemistry, vol. 2013, Article ID
230860, 7 pages, 2013. doi:10.1155/2013/230860
[9] Arnoldsson, E., Bergman, M., Matsinhe N., & Persson, K. M.
Assessment of drinking water treatment using moringa oleifera
natural coagulant. VATTEN, (2008). 64: 137-150.
[10] Okuda, T., Baes, A. U., Nishijima, W., & Okada, M. Improvement
of extraction method of coagulation active components from
moringa oleifera seed. Wat. Res., (1999). 33: 3373-3378.
[11] Ramamurthy, C., Maheswari, M. U., Selvaganabathy, N., Kumar,
M. S., Sujatha, V., & Thirunavukkarasu, C. Evaluation of eco-
friendly coagulant from trigonella foenum-graecum seed.
Advances in Biological Chemistry, (2012). 2: 58-63.
[12] Abu Hassan, M. A., Li T. P., & Noor, Z. Z. Coagulation and
flocculation treatment of wastewater in textile industry using
chitosan. Journal of Chemical and Natural Resources Engineering.
4: 43-53.
[13] Kumar, P., Yadava, R. K., Gollen, B., Kumar, S., Verma, R. K., &
Yadav, S. Nutritional contents and medicinal properties of wheat:
a review. Life Sciences and Medicine Research, (2011). 22.
[14] Wheat Foods Council, 2011, http:// www.wheatfoods.org/
sites/default/files/attachments/kernel-wheat-how-flour-milled.pdf
(accessed 10 Dec. 2013).
[15] Sarpong, G. & Richardson, C.P. Coagulation efficiency of moringa
oleifera for removal of turbidity and reduction of total coliform as
compared to aluminum sulfate. African Journal of Agricultural
Research, (2010). 5: 2939-2944.
[16] Abdul Jamil, A. K. A., Ahmad Junan, S. A., Eng, S.C., Tik, L. B.
Chemistry for matriculation 2. Malaysia: Oriental academic
publication; 2005.
[17] Bhatia, S., Othman, Z., & Ahmad, A.L. Pretreatment of palm oil
mill effluent (POME) using moringa oleifera seeds as natural
coagulant. Journal of Hazardous Materials, 145 (2007) 120–126.