CHEMICAL TREATMENT OF WASTEWATER FROM PALM OIL MILL EFFLUENT (POME) IN COOPERATE WITH BIODIESEL
PRODUCTION
Chin Siaw Yin
TD 897 C539 2013 Master of Environmental Science
(Land Use and Water Resource Management) 2013
•
I'
: I
i
P4Jsat Khidmat MakJumat Akademik UNIVERSm MALAYSIA SARAWAK
CHEMICAL TREATMENT OF WASTEWATER FROM PALM OIL MILL EFFLUENT (POME)
IN COOPERATE WITH BIODIESEL PRODUCTION P.KHIOMAT MAKLUMAT AKAOEMIK
1IIIIIIIIIfiiwiIIIlUll 1000245936
CHIN SlAW YIN
A dissertation submitted in fulfilment of the requirement of the Master of Environmental Science (Land Use and Water Resource Management)
Faculty of Resource Science and Technology
UNIVERSITI SARAWAK MALAYSIA
2013
DECLARATION
With this, I hearby declare that this thesis is my original work, except for the citations, all
of which have been duly acknowledged. Apart from that, I would like to declare that it has
not been previously submitted concurrently for any other degree of UNIMAS or other
institutions.
CHIN SlAW YIN
Matric No: 11 031872
Date:
Master of Environmental Science Faculty of Resource Science and Technology Universiti Malaysia Sarawak
ACKNOWLEDGEMENT
This final year project was completed with the grace of God, may all the glory be unto Him!
I would also wish to express my sincere gratitude to my supervisor, Dr. Tay Meng Guan
for giving me an opportunity to work on this project. Thanks to his guidance and advices
throughout the project. Not forgetting my laboratory mate Ivy Moh Heng Shi for sharing
information and her encouragement during the works. I would also like to dedicate my
sincere gratitude to my SLUSE cohort 11 course mates for their sharing of ideas,
knowledge and experience throughout this program. Besides that, I would also wish to
express my special thanks to Faculty of Resource Science and Technology for providing
the most congenial and supportive atmosphere throughout my project. Lastly, I wish to
express my gratitude to my beloved family members and friends who have prayed and
supported me throughout my study.
II
.....
AWARD
Chin S.Y. Chemical treatment of wastewater from palm oil mill effluent (POME) in
cooperate with biodiesel production, in competition of Shell Inter-Varsity Student Paper
Presentation Contest (S-SPEC 2013) with the theme Fuelling Sustainable Green Energy, at
Universiti Teknologi Malaysia, Johor.
Prize: 151 runner up
III
PUBLICATION
Chin, S.Y., Moh, I.H.S. & Tay, M.G.* Bio-fuel recovery and wastewater treatment of Palm
Oil Mill Effluent (POME), in preparation.
IV
r
Pusat Khidmat Maklumat Akademik UNTVERSm MALAYSIA SAKAWA)(
TABLE OF CONTENTS
Acknowledgement
Award
Publication
Table of Contents
List of Tables
List of Figures
Abstract / Abstrak
Chapter One INTRODUCTION
Chapter Two LITERATURE REVIEW
2.1. Treatment of POME
2.2 Chemical Oxygen Demand (COD) Treatment
2.3 Alkaline Treatment
2.4 Industrial Water Reclamation and Reuse
Chapter Three METHODOLOGY
3.1 Sampling and Storage
3.2 Water Quality Analyses
3.2.1 Temperature
3.2.2 Turbidity
3.2.3 Dissolve Oxygen (DO)
3.2.4 pH
II
III
IV
V
VII
VIII
IX
1
8
8
12
16
18
22
22
23
23
23
23
24
v
Chemical Oxygen Demand (COD) (Hach Method 3.2.5 24
8000)
3.2.6 Biological oxygen demand (BODs) 24
3.2.7 Total suspended solid (TSS) 25
3.2.8 Nutrients Analysis 26
3.2.8.1 Nitrate (N03-N) 26
3.2.8.2 Ammoniacal Nitrogen (NH3-N) 26
3.2.8.3 Phosphorus Reactive (P04 3-) 27
Oil and Grease Hexane Extractable Gravimetric 3.2.9 27
Method
3.3 Chemical Treatment with Fenton and photo-Fenton 28
Chapter Four RESUL TS AND DISCUSSION 29
4.1 Characteristics of POME 29
4.2 Water Quality of the Wastewater after Biodiesel 30Production through Transesterification Process
4.3 Chemical Treatment with Fenton and Photo-Fenton 37 Process
Chapter Five CONCLUSION 41
43References
VI
LIST OF TABLES
Table Page
General characteristics of POME and effluent discharge 2.1 9
standard by DOE
Advantages and disadvantages of methods employed for 2.2 11
treatment of POME (Poh& Chong, 2009).
Summary of water quality parameters relevant to 2.3 industrial wastewater reclamation, recycling and reuse 20
(adapted from Asano& Levine, 1998).
Characteristics of POME samples and regulatory 4.1 29
discharge limit (DOE)
4.2 Characteristics of wastewater after biodiesel production 35
Characteristics of wastewater after Fenton and photo4.3 38
Fenton treatment
VII
--
1
LIST OF FIGURES
Figure Page
Mass balance (in kg) of production process of a study 3 1.1
factory
Residents of Selangor state suffered from water crisis as I'
1.2 the state is experiencing a shortage of clean water. The 5 residents are queuing up for water supply.
1.3 Anaerobic pond (left) and the drainage near the pond. 7I'
4.1 Raw sample of PO ME 30
4.2 Wastewater after biodiesel production from POME 34
The dilution (xl 000) of wastewater prior and after Fenton 37 4.3
treatment
The dilution (x 1 000) of wastewater prior and after photo- 37 4.4
Fenton treatment.
Pinkness developed on both the wastewaters which were 40 4.5 treated with Fenton or photo-Fenton
-
VIII
l
Cbemical Treatment ofwastewater from Palm Oil Mill Effluent (POME) In Cooperate witb Biodiesel Production
Chin Siaw Yin
Master of Environmental Science Faculty of Resource Science and Technology
Universiti Malaysia Sarawak
ABSTRACT
(The international demand for oil palm (Elaeis guineensis) is increasing, which lead to the rapid growth of palm oil industry in Malaysia. However, the industry is facing the challenge of sustainable water management due to large volume of water is used in the palm oil mill for the oil extraction process and increase of production of wastewater which is known as palm oil mill effluent (POME) This study detennines the POME water quality prior and after the POME is used to produce biodiesel. Indeed, further chemical treatment was used in order to obtain a better water quality. The objective of treating the POME is to reuse or recycle the water in the mill plant for example in the cooling process. Thus, the findings from this study helps to reduce freshwater consumption of the palm oil plant and minimum oil residue in the POME before it discharge to the receiving environmental bodies. Besides pollution prevention of the river, wastewater recycling within industry is also a resource recovery which helps reduce wastewater generation and save the production cost of the industry. In this study, POME was treated by de-oil process (biodiesel production) and the residual wastewater was treated with Fenton and photo-Fenton process, which COD reduction show high efficiency, which were 89.36% reduction through Fenton and 90.78% through photo
Fenton process.
Key words: palm oil mill effluent, wastewater treatment, COD reduction
ABSTRAK
Pennintaan antarabangsa terhadap minyak kelapa sawit (Elaeis guineensis) semakin meningkat dan ini telah
membawa kepada pertumbuhan pesat industri minyak saw it di Malaysia. Walau bagaimanapun, industri ini menghadapi cabaran pengurusan air yang mampan kerana penggunaan jumlah air yang banyak di kilang sawit dan pengeluaran air sisa yang dikenali sebagai palm oil mill ejjluenl (POME). Kajian ini bertujuan untuk menentukan kualiti air POME sebelum dan selepas POME digunakan untuk menghasilkan biodiesel. Malab, rawatan kimia telah digunakan dalam usaha untuk mendapatkan kualiti air yang lebih baik. Objektif I
merawat POME adalah untuk guna semula atau kitar semula air di kilang, seperti air untuk proses I
penyejukan. Oleh itu, dapatan kajian ini dapat membantu untuk mengurangkan penggunaan air oleh kilang sawit dan sisa minyak dalam POME sebelum ia dilepaskan ke alam sekitar. Selain dapat mencegah I
Ipencemaran sungai, kitar semula air sisa dalam industri juga merupakan salah satu usaha pemulihan sumber yang membantu mengurangkan penghasilan sisa buangan dan menjimatkan kos pengeluaran industri. Dalam kajian ini, POME dirawat melalui proses de-oil (penghasilan biodiesel) manakala baki air sisa dirawat dengan Fenton dan photo-Fenton proses. Pengurangan COD dicapai sebanyak 89.36% melalui Fenton dan 90.78% melalui photo-Fenton proses.
Kata kunci: air sisa kelapa sawit, rawatan air sisa, pengurangan keperluan oksigen kimia (COD)
IX I
.
CHAPTER ONE
INTRODUCTION
The oil palm (Elaeis guineensis) demand in the world is increasing and leading to the rapid
growth of palm oil industry in Malaysia. According to the report from Saifuddin & Dinara
(2011), there were more than 16 million tonnes of crude palm oil is produced in Malaysia
just within year 2009. This number is increasing due to the demand of crude palm oil is
becoming greater over the decades due to its uses as cooking oil and biofuel. Indeed,
biodiesel production from crude palm oil is an alternative source of energy and is able to
lessen the dependency on the rapidly depleting fossil fuels, which is not a renewable
resource. Based on the studies from variety reports, biodiesel is more environmental
friendly compared to fossil fuel as it reduces the emission of green house gases such as
carbon dioxide and nitrogen oxide in the diesel exhaust.
Biodiesel consists of long-chain fatty acid esters. It is typically produced
through transesterification reaction of the vegetables oil with short chain alcohol such as
methanol or ethanol. During the process, catalyst is used to yield mono-alkyl esters
(biodiesel) and glycerin. The most common used palm biodiesel is the blends of 20% palm
oil with 80% petroleum diesel, which is labelled as B20. Biodiesel B20 and lower blends
can be used in unmodified diesel engine. Pure biodiesel (ElOO) not commonly used as
certain engine modifications are required to avoid maintenance and performance problems.
Any biodiesel which is registered as a fuel has to meet international standards, which are
1
American ASTM 6751 or Europe's EN 14214. In addition, as negotiated in Kyoto Protocol,
rich countries need to repay climate debt by undertaking severe cuts in green house gases
emission. Therefore, the carbon credits derived under Kyoto Protocol has increased the
economic viability of biodiesel since it promises the reduction of green house gases
emissions compared to fossil fuel and petroleum.
Palm oil mills are considered as net energy producers as sufficient energy for
milling purposes can be derived from burning of the biomass (Ng, 2006). For instance, the
co-products such as empty fruit brunches, waste mesocarp and shell from the milling
process are burnt to produce heat to the boiler, which subsequently produce the steam in
the sterilizing process (Soraya et at., 2012). In some mills, methane gas is produced from
the anaerobic lagoon can also be used for electricity generation purpose.
However, palm oil processing mill involves the usage oflarge volume of water.
Water is used in different points in the processing min, includes clarification sludge, fruit
washing water, sterilization condensates, hydro cyclone drain-off and various boiler, tank
and decanters drain (Igwe & Onyegbado, 2007). The used water always ended up as
brownish high organic content wastewater, which is known as palm oil mill effluent
(POME). According to Tokyo Electric Power Environmental Engineering Corporation
study report on the Bukit Pasir Palm Oil Mill at Johor, Malaysia in 2009, the ratio of
POME produced is approximately 0.6 tonnes per tonne FFB processed with a total amount
oforganic substantial around 145,000 tonnes per annum. In addition, there was about more
than half the water input of the mill will result in POME (DOE, 1999). Figur~ 1.1 shows
the mass balance (in kg) of production process of a local mill.
2
----~---:"11,........p.-MICI, I~~I YL._._____
• ~ T __i4- __lIN"
I I
..-.-. ,• I
- --- --- ---- ___ I
NIII-t-1Mr IL SeJ-w1ioNo r":"""'- FRNt- I...
'---"TT'"" ~r iU -----' I Nut 110 ~
Aa~
~-:>S1MJ155
KtTDrl55
,• I
I 1 I
: SaDd I I
Or.rulC'r cae J1 '''''.1 Hol.-.a,rr ...
( ) 00/ -- I. _ ..~
0.1';' v.u OIl _ au
.. lIio:r
Figure 1.1: Mass balance (in kg) of production process of a study factory.
According to Ahmad and co-workers (2005), it is estimated that one tonne of
crude palm oil (CPO) will result in 2.5-3.5 m3 POME. Due to high content of organic
substances in the POME, it needs to be treated to comply with the requirements from
Department of Environment (DOE) before discharged into the receiving water bodies.
3
Water is essential in socio-economic development and also helps in
maintaining a healthy environment. Water is second to oxygen as being essential for life
(Skipton et at., 2011). People can survive days, weeks, or even longer without food, but
cannot survive without any water intake for four days. About 75 percent of human body is
consisted of water. Water is essential for cellular homeostasis and life, that it is needed for
regulating the activities of body fluids, cells, tissues, lymph, blood and glandular secretions
(Popkin et at., 2010). Besides that, water is also needed for our daily life activities such as
cleaning, agriculture, transportation and many more anthropogenic activities. It was
believed that about one-third of the world's population now is facing moderate to severe
water stress, and this number will be increased to two-thirds by 2025 due to the current use
and management of freshwater is not sustainable in many countries (Kuylenstierna et at.,
2009). Though two-thirds of the Earth surface is water, about 98% of water is sea water
which is not suitable to consume. Moreover, the remaining 2% freshwater is ice, less than
0.3% of water on Earth is directly available to us. Like other natural resources, water
resource is at constant risk of being further degraded and gradually become limited. Figure
1.2 shows the situation of water crisis that occurred in Selangor in 2012.
4
Pusat Khidmat Maklumat Akademik 1 "''1''u~m "ALAVSt4 s ,Ut\''' ' , v I
Figure 1.2: Residents of Selangor state suffered from water crisis as the state is experiencing a shortage of clean water. (Source: New Strai ts Times, 2013).
Sustainable water use and management is important to overcome the problem
of distortion of water quality and scarcity of water resources. From the viewpoint of
industries, the non-biodegradable pollution discharges into the water system builds up,
rapidly deteriorate water quality and having great impact on the world's ecosystem.
Industrial water management should strive for optimisation of the water use and emissions,
rather than minimization (Lens et al., 2002). For instance, there are a number of
environmental problems at the oil palm factories, such as high water consumption, the
generation of a large amount of wastewater with a high organic content, and the generation
of a large quantity of solid wastes and air pollution (Chavalparit et al., 2006). If the
effluent is discharged without complying to the standard discharge limit by DOE, there
will be severe consequences to the river aquatic ecosystem. For instance, the suspended
solids may settle into the river bed, covering and burying most of the benthic organisms,
and destructing the spawning ground of fish and fish eggs (Lau, 20 II). In addition, river
water will increase in turbidity, no longer transparent and depletion of oxygen of the
aquatic lives.
5
Due to the serious negative impacts to the environment, water reclamation and
recycling is recommended to be applied in several industries. Water usage in industries can
be closing local or regional water cycles. These cycles will have to be closed. Whenever
the water cycle in a factory is imbalance, the supply of water (from renewable water
sources) to be increased or recirculation must be increased (Lens et aI., 2002). In other
words, when the amount of renewable water resource is limited, recirculation of water
must be increased. Therefore, water recycling shall be an essential element of sustainable
and integrated water resource management in industries. For instance, in some factories, in
order to reduce the water usage, the sterilizer condensate can be reused as feed boiler water
and treated effluent are using as cooling water.
Even though oil palm industry has coped with the Clean Development
Mechanism (COM), it is still facing the challenge of sustainable water management. The
POME is a thick brownish acidic liquid, which contains high amounts of total solids
(40,500 mg/L) , high chemical oxygen demand (COD) value (50,000 mg/L) and high
biochemical oxygen demand (BOD) value (25,000 mg/L) that can caused severe pollution
to water resources (Ahmad et ai., 2005). Therefore, POME is considered as one of the
most detrimental waste if discharge untreated to the environment (Rupani et ai. , 2010). In
addition, POME normally constitute of 95-96% of water, 0.6-0.7% of oil and grease and 4
5% of solids or organic matter (ldris et aI., 2010). From the perspective of resource
recovery, the residual oil can be extracted from POME as biodiesel. For instance, with
toOOL of POME produced, 60-70L of biodiesel can be produced. Figure 1.3 shows the
anaerobic pond of a local mill and the drainage where the POME was sent to the anaerobic
pond.
6
Figure 1.3: Anaerobic pond (left) and the drainage near the pond.
This study aims to determine the POME water quality prior and after it is used
to produce biodiesel. Indeed, further chemical treatment was used in order to obtain a
better water quality of POME. The main objective of treating the POME is to reuse the
water in the mill plant for example in the cooling process (Lens et at., 2002). Recycle the
used water is a way to reduce the discharge of wastewater to the environment, which will
reduce the pollution to the rivers. Besides pollution prevention of the river, wastewater
recycling within industry is also a resource recovery which helps saving the production
cost of the industry. Hence, it shall be an essential element of sustainable and integrated
water resource management.
7
CHAPTER TWO
LITERATURE REVIEW
2.1 Treatment of POME
Although the oil palm industry has contributed significantly to our country economic
growth, the industry is still facing the challenge of environment protection, economic
viabilities and sustainable development (Salihu & Alam, 2012). The effluent from the miHs
is known as one of the most detrimental pollutants due to its high total solids content, high
organic content, high COD value and high BOD value.
During the extraction of crude palm oil from the fresh fruit bunch, large
amount of water is used. Up to about 1.5 m3 of water are typically used in palm oil mill to
process one tonne of fresh fruit brunch, of which about 50% of the water will then result in
POME (DOE, 1999). The other 50% of the water is lost as steam, lost through sterilizer
exhaust and pipe leakages. In Malaysia, the environmental control of palm oil mills is
under the Environmental Quality (Prescribed Premises) (Crude Palm Oil) Regulations
1977, promulgated under the enabling powers of Section 51 of Environmental Quality Act.
Table 2.1 shows the general characteristics of combined POME and the prevailing effluent
discharge standards for palm oil mills.
8
Table 2.1: General characteristics of POME and effluent discharge standard by DOE.
Parameter
pH
Biological Oxygen Demand (BOD;
3-day, 30°C)
Chemical Oxygen Demand (COD)
Total Solids (TS)
Total Suspended Solids (TSS)
Total Volatile Solids (TVS)
Oil & Grease (O&G)
Ammoniacal Nitrogen (NH3-N)
Total Nitrogen (TN)
Phosphorous
Mean
I 4.2
25,000
50,000
40,500
18,000
I 34,000
1 6,000
35
750
I 180
Range
3.4-5.2
10,000-44,000
16,000-100,000
11,500-79,000
I 5,000-54,000
9,000-72,000
150-18,000
. 4-80
80-1,400
-
Effluent
discharge
standard
5-9
100
* * 400
-I 150
150
20Q
-
I
Note: All parameter 's umts In mg/L except pH. • No discharge standard after 1984.
Source: Industrial Processes and Environment - Crude Palm Oil Industry (DOE, 1999)
Various treatment systems are employed by the mills to treat the effluent. Like
typical water treatment, primary treatment of POME is the physical treatment to remove
suspended solids such as sand and grit. The physical treatment involves screening,
sedimentation filtration and oil removal in oil traps prior to secondary treatment (Igwe &
Onyegbado,2007).
Biological ponding system which is a multi-stage process is typically used for
ME treatment system in Malaysia (Salihu & Alam, 2012). The biological treatment is
.. on anaerobic, aerobic and facultative processes. Among the palm oil mills in
Malaysia, more than 85% have adopted the ponding system for POME treatment (Ma et al.,
9
1993), while the others opted for open digesting tank (Yacob et at., 2005). Open digesting
tanks are used when there is insufficient area for ponding treatment system (Salihu & Alam,
2012). Biological treatment is preferred as the organic content of POME is generally
biodegradable and it is cost-effective. POME treatment either through ponding system or
open digester system produce good quality discharge which the final discharge with BOD
less than 100 mg/L.
Nevertheless, biological treatment largely relies on the growth and metabolic
activities of suitable microorganisms to decompose the organic matter into simple end
products, which are methane, carbon dioxide, hydrogen sulphide and water. In addition,
methane gas produced is seldom captured and is released to atmosphere. Thus, the existing
biological treatment system of palm oil mil is considered as one of the major contributors
to green house gas emission in Malaysia (Mumtaz et at., 2010). Since methane gas can be
an auxiliary fuel for the mill, closed digesters are employed in some mills to capture the
methane gas. Table 2.2 shows the advantages and disadvantages of some common POME
treatment systems in Malaysia.
10
Table 2.2: Advantages and disadvantages of methods employed for treatment of POME (Poh& Chong, 2009).
Disadvantages
Anaerobic
AdvantagesTreatment type
Minimal energy requirement (no Vast area of land required for
aeration), methane gas generation as a conventional digesters, longer
valuable product, the sludge generated retention time and slow start-up
can be used for land application
Aerobic Shorter retention time, efficient in Required higher energy (aeration),
handling toxic wastes unsuitable for land application as the
rate of toxic inactivation IS much
slower than that of anaerobic.
Membrane Short membrane life, membrane
treatment plant, effective and efficient
Small area required for membrane I
fouling, expensive compared to
treatment conventional treatment
Evaporation The solid concentrate fonned is I High energy consumption
utilized as feed material for fertilizer
processing
POME contains high concentration of carbohydrate, protein, nitrogenous
compounds, minerals and lipids (Habib et aI., 1997). Various biotechnological processes
have done to make use the constituents in POME to produce useful products (Salihu &
Alam, 2012). For instance, POME has been converted into value added products such as
carotenoid (Wahid et al., 2004), fertilizer and compost (Basiron & Weng, 2004) and citric
acid (Alam et al., 2008).
11
202 Chemital Oxygen Demand (COD) Treatment
COD measures the amount of oxygen that is required by the water in the oxidation and
decomposition processes, especially the decomposition of organic matter and oxidation of
inorganic substances (APHA, 1999). COD in wastewater is mainly dependent on the total
sugar content (Rosma & Ooi, 2006). The wastewater form biodiesel production is
nonnally with high pollutant loads of fats, oils, methanol, soaps and basic catalysts which
have to be treated before been discharged into the river. This kind of wastewater IS
typically represented by the parameters COD, TOC and BOD (Ramirez et ai., 2012).
With chemical treatment, COD and BOD in the wastewater can be reduced by
removal of the suspended solids and organic content in the water through coagulation
method. Coagulation is defined as destabilization by particle charge neutralization and
°tial aggregation of colloids. In coagulation process, the most effective coagulant aids are
valent and trivalent metallic ions, such as aluminium sulphate and ferric chloride. The
ice and dose of the chemicals added will depend on the characteristics of the water to
tmlted. The dose rate may be from 5 to 100 mg/L of coagulant (Mann & Williamson,
). In general, coagulation is typically joined with flocculation which is necessary for
chemical treatment. Flocculation is agglomeration of coagulated colloidal and finely
.'*~ suspended material either by physical mixing or by chemical coagulant aids. In
°tion, chemical treatment is done to make coagulation and flocculation more efficient
adding chemicals to adjust the chemical charges on the contaminants (Russell, 2006) .
•• IJedJune:ntaltloln, the dirt can be removed through the filtration process.
12
Flocs which are the dirt particles formed from the coagulation process, will
then stick together forming larger particles. Large particles settle to the bottom will remain
in the tank while water continues to flow to the next process, whereas the sediments of
large particles will be removed through filtration process. Water flows through a porous
material that catches the remaining dirt or dissolved solids and allows water particles to
flow through it.
Besides chemical treatment, biological treatment of wastewater from biodiesel
production using Rhodotorula mucilaginosa also has been reported concerning its
efficiency in reducing the COD and BOD. However, this process is only useful at small
scales (Suehara et a!., 2005). Biological treatment requires adjusting the pH and adding
nutrients for the growth and survival of the microbes. For palm oil industry, biological
treatment of POME through anaerobic lagoon can cause emission of methane to the
atmosphere, which may contribute to green house effect.
Furthermore, advanced oxidation process such as Fenton and photo-Fenton
process have shown efficiency in COD removal of various types of high pollution strength
industrial wastewater. Advanced oxidation process (AOP) is defined as oxidation process
in which hydroxyl radicals are produced as the main oxidants involved. Fenton's reagent is
a system based on generation of very reactive free radicals which have stronger oxidation
potential than ozone (De Heredia, 2001). The hydrogen radicals generated can react with
and oxidize most pollutants by destructing the chemical bonds of the pollutants (Shahwar
et aI., 2012).
13
