WASTE TO VALUABLE BY PRODUCT: UTILIZATION OF CARBONISED DECANTER CAKE FROM PALM OIL MILLING PLANT AS AN EFFECTIVE ADSORBENT FOR HEAVY METAL IONS IN AQUEOUS SOLUTION NUGROHO DEWAYANTO Thesis submitted in fulfillment of the requirements for the award of the degree of Master of Engineering in Chemical Engineering Faculty of Chemical and Natural Resources Engineering UNIVERSITI MALAYSIA PAHANG JULY 2010
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WASTE TO VALUABLE BY PRODUCT: UTILIZATION OF … filepenjerapan didapati mengikut model kinetik order kedua pseudo. Parameter termodinamik seperti enthalpy piawai (Mb), entropi piawai
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WASTE TO VALUABLE BY PRODUCT: UTILIZATION OF CARBONISED DECANTER CAKE
FROM PALM OIL MILLING PLANT AS AN EFFECTIVE ADSORBENT
FOR HEAVY METAL IONS IN AQUEOUS SOLUTION
NUGROHO DEWAYANTO
Thesis submitted in fulfillment of the requirements for the award of the degree of
Master of Engineering in Chemical Engineering
Faculty of Chemical and Natural Resources Engineering UNIVERSITI MALAYSIA PAHANG
JULY 2010
vii
ABSTRACT
Palm oil milling plant generates large amount of waste that was proven to cause environmental problems. About 40 kg decanter cake was generated from each ton of fresh fruit bunch processed. Previous studies suggested agricultural waste could be employed as heavy metal ion adsorbent. Due to the similarity of decanter cake with other agricultural waste we proposed to explore the use of decanter cake as an adsorbent for heavy metal ion removal.
Utilization of decanter cake as an effective adsorbent for Cd 2 , Cu2 and Pb2 ion removal from aqueous solution has been studied. The decanter cake was first dried at 105 °C and then carbonized at various temperatures. The resulting carbonized decanter cake were tested for removing Cd2 , Cu 7+ and Pb2 ions. Proximate analysis using thermogravimetry analysis of decanter cake carbonized at 500 °C indicated that the adsorbent contained 4% moisture, 21% volatile,23% fixed carbon, and 52% ash. Adsorption test were normally carried out by mixing 1.0 g of the decanter cake in 100 mL aqueous solution of the various ions. The concentration of metal ions in the solutions used is in the range of 100 - 1000 mg/t.
The results of adsorption studies indicated that the removal of metal ions was highest in the case of Pb2 when the carbonization temperature was 500 °C and 600 °C in the case of Cd2 and Cu2 . Maximum removal of the Cd2 , Cu2 and Pb2 were also observed to take place when the pH of the solution is in the range of 4 - 5. Langmuir and Freundlich isotherm models were used to fit the isotherm experimental data. The maximum uptakes of Cd2 , Cu2 and Pb2 onto the carbonized decanter cake in this study were estimated to be 24, 23, and 97 mg/g respectively. Adsorbed metal ions can be desorbed from adsorbent using dilute HC1 solution. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. Thermodynamic parameters such as standard enthalpy (MI"), standard entropy (AS-) and Gibbs free energy (AG-) were determined. Adsorption process was endothermic and had negative value of Gibbs free energy changes. The competitive adsorption characteristics of binary and ternary heavy metal ions Cd2 , Cu2 and Pb2 on PDC500 were investigated in batch systems. Equilibrium adsorption data showed that PDC500 displays a high selectivity toward one metal in two-component or a three-component system with an affinity order of Pb2> Cu2 > Cd2 Chemical activation of decanter cake using ZnC12 increased the maximum adsorption capacity for Cd2 , Cu2 and Pb2 significantly to 52, 44, and 159 mg/g respectively. Kinetic and thermodynamic properties of adsorption were affected by chemical activation.
Scale up of the batch process into industrial scale was explored using the Langmuir parameter from experimental data. A three-stage continuous counter current adsorption unit gave the best adsorption performance for Pb2 ion removal in term of minimum adsorbent consumption.
viii
ABSTRAK
Kilang ke1apa sawit menghasilkan sejumlah besar bahan buangan di mana ia menjadi punca terhadap pencemaran alam sekitar. Setiap satu tan tandan buah segar kelapa sawit yang diproses menghasilkan 40 kg decanter cake. Kajian terdahulu mencadangkan bahawa bahan buangan pertanian dapat digunakan sebagai penjerap ion logam berat. Memandangkan decanter cake mempunyai persamaan dengan bahan buangan pertanian yang lain, ia dicadangkan sebagai bahan penjerap untuk menyingkirkan ion logam berat.
Penyingkiran ion-ion Cd2 , Cu2 dan Pb2 daripada decanter cake minyak kelapa sawit telah dikaji. Decanter cake dikeringkan terlebih dahulu pada 105 °C dan path pelbagai suhu. Hasil pirolisis mendakan itu diuji untuk menyingkir ion-ion Cd2 , Cu2
dan Pb2t Analisa pirolisis mendakan pada 500 °C dengan menggunakan 'thermogravimetry' mendapati bahawa penjerab mengandungi 4% kelembapan, 21% bahan ruap, 23% karbon mampat dan 52 % abu. Ujian penjerapan dijalankan dengan mencampurkan 1.0 g mendakan ke dalam 100 mL larutan pelbagai ion. Kepekatan ion-ion logam yang digunakan di dalam larutan adalah dalam lingkungan 100-1000 mg/L.
Hasil ujikaji penjerapan menunjukan penyingkiran ion-ion Pb 2 adalah tinggi pada suhu 500 o o C dan 600 C bagi ion Cd2+ dan Cu2+ Penym i gkiran on-ion Cd2+ , Cu2+ and Pb2 adalah maksimajuga diperhatikan apabila pH larutan di datam lingkungan 4-5. Model isoterma Langmuir dan Freundlich telah digunakan untuk mengukuhkan lagi data eksperiment. Maksimum ion- ion Cd2 , Cu2 dan Pb2 terhadap pirolisis mendakan adalah dianggarkan 24, 23 dan 97 mg/g masing-masing. Ion-ion logam yang terjerap botch dinyahkan dan penyerap dengan menggunakan tarutan HCL cair. Kinetik penjerapan didapati mengikut model kinetik order kedua pseudo. Parameter termodinamik seperti enthalpy piawai (Mb), entropi piawai (AS-) dan tenaga bebas piawai (AG-) telah ditentukan. Pengaktifan kimia bagi hasil mendakan dengan menggunakan ZnC12 meningkatkan keupayaan penjerapan maksimum bagi Cd 2 , Cu2
dan Pb2 sebingga 52, 44 dan 159 mg/g. Ciri-ciri kinetic dan termadinamik penjerapan telah dipengaruhi oteh pengaktifan secara kimia. Ciri-ciri perbezaan penjerapan binari dan ketiga bagi ion-ion logam berat Cd2 , Cu2 dan Pb2 terhadap PDC500 telah dikaji dalam sistem kelompok. Data keseimbangan penjerapan menunjukan bahawa PDC500 memberikan kupayaan memitih yang tinggi terhadap togam dalam system dua komponen atau tiga komponen dengan turutan Pb 2 > Cu2 > Cd2t
Berdasarkan data-data yang diperolehi, sistem berskala makmat dinaikskata kepada skala industri menggunakan parameter Langmuir. Didapati, proses penyingkiran optimum ion Pb2 berdasarkan penggunaan minimum bahan penj crap diperotehi apabita proses penjerapan tiga peringkat arus melawan berterusan digunakan.
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TABLE OF CONTENTS
Contents
SUPERVISOR'S DECLARATION
111
STUDENT'S DECLARATION
iv
ACKNOWLEDGEMENT vi
ABSTRACT vii
ABSTRAK viii
LIST OF TABLES xli
LIST OF FIGURES xiv
LIST OF SYMBOLS xvii
LIST OF ABBREVIATIONS xviii
CHAPTER 1 INTRODUCTION
1
1.1 Waste 1
1.2 Waste Reduction 4
1.3 Adsorption Process 7
1.4 Problem Statement
8
1.5 Objectives 8
1.6 Scope Of Work
9
1.7 Thesis Structure 9
CHAPTER 2 LITERATURE REVIEW
11
2.1 Decanter Cake Of Palm Oil Milling Plant
11
2.2 Cadmium, Copper And Lead Ions In Environment
13
2.2.1 Cadmium in Environment
13 2.2.2 Copper in Environment
15
2.2.3 Lead in Environment
17 2.2.4 Heavy metal removal from environment
18
2.3 Adsorbent
21
x
2.3.1 Types of adsorbent 21 2.3.2 Agricultural waste as adsorbent 23 2.3.3 Carbonized agricultural waste as adsorbent 26
2.4 Adsorption Of Heavy Metal Ion 28
2.4.1 Adsorption mechanism 28 2.4.2 Effect of pH in metal ion adsorption 30 2.4.3 Adsorption isotherm 31 2.4.4 Adsorption kinetic 39 2.4.5 Adsorption thermodynamic 41 2.4.6 Desorption 47 2.4.7 Adsorption selectivity 47 2.4.8 Effect of activation of carbonized decanter cake on adsorption parameter48
2.6 Utilization Of Atomic Absorption Spectrometry In Heavy Metal Analysis 57
2.6.1 Basic Principles of Atomic Absorption Spectrometry 57 2.6.2 Quantitative analysis 58 2.6.3 Analytical condition for Cd 2 , Cu2 and Pb2 ion analysis 59
CHAPTER 3 MATERIALS AND METHODS 61
3.1 Material Preparation 61
3. 1.1 Adsorbent and reagents preparation 61 3.1.2 Characterization 62
3.2 Heavy Metal Ion Analysis Using Atomic Absorption Spectrometry 62
3.2.1 Calibration curve 62 3.2.2 Preparation of sample 63
3.3 Experiments 63
3.3.1 Equilibrium time 63 3.3.2 Effect of carbonization temperature 64 3.3.3 Effect of pH 64 3.3.4 Adsorption isotherm 64 3.3.5 Desorption studies 65
3.3.6 Kinetic studies 65
3.3.7 Thermodynamic studies 65 3.3.8 Competitive adsorption of metal ions in binary and ternary ion mixture 66 3.3.9 Effect of chemical activation on adsorption parameters 66
xi
CHAPTER 4 RESULTS AND DISCUSSIONS
67
4.1 Introduction 67
4.2 Characterization 68
4.2.1 Thermogravimetry analysis
68 4.2.2 Scanning Electron Microscope and EDX Spectrometry
71
4.2.3. Surface area and porosity of adsorbent
75
4.3 Adsorption Studies 77
4.3.1 Equilibrium time 78
4.3.2 Effect of carbonization temperature
79 4.3.3 Effect of pH
80 4.3.4 Adsorption isotherm
81 4.3.5 Desorption 86
4.4 Kinetic And Thermodynamic Studies
89
4.4.1 Kinetic studies 90
4.4.2 Thermodynamic studies
95
4.5 Competitive Adsorption 98
4.6 Effect Of Decanter Cake Activation 101
4.6.1 Effect of activation on adsorption isotherm
102 4.6.2 Effect of activation on adsorption kinetic
105
4.6.3 Effect of activation on adsorption thermodynamic
110
4.7 Scale Up Of The Adsorption Process
112
4.7.1 Single stage batch
113 4.7.2 Multiple stages batch
114
4.7.3 Single stage continuous 114
4.7.4 Multistage countercurrent
115
CHAPTER 5 CONCLUSION AND RECOMMENDATION FOR FUTURE
RESEARCH 117
5.1 Conclusion 117
5.2 Recommendation For Future Research
118
REFERENCES 120
xli
LIST OF TABLES
Table Title Page
2.1 Physical and chemical properties of cadmium 13
2.2 Physical and chemical properties of copper 15
2.3 Physicochemical properties of common copper compounds 16
2.4 Physical and chemical properties of lead 17
2.5 Different precipitant used for heavy metal recovery 19
2.6 Typical application of commercial adsorbents 24
2.7 Summary of modified plant wastes as adsorbents for the removal of 25 heavy metal ions from aqueous solution
2.8 Summary of carbonaceous adsorbents derived from agricultural 27 waste or agricultural by-product
2.9 Langmuir parameters and conditions for adsorption of heavy metals 36 by various kinds of biosorbents
2.10 Freundlich parameters and conditions for adsorption of heavy metals 38 by various kinds of biosorbents
2.11 Kinetic studies on heavy metal biosorption 42
2.12 Thermodynamic studies on heavy metal biosorption 45
2.13 Analytical conditions for Cd2 , Cu2 and Pb2 analysis. 57
3.1 Concentration variation of standard solution for each metal ion 60
4.1 Proximate analysis of adsorbent from decanter cake at various 68 carbonization temperatures
4.2 Quantitative result of EDX spectrometry on carbonized decanter 72 cake
4.3 BET surface area and porosity of adsorbents 74
4.4 Correlation between carbonization temperature, its properties and 77 metal ion uptake
4.5 Langmuir and Freundlich parameters for adsorption of metal ions 83 onto pyrolized decanter cake
4.6 Comparison of Langmuir parameters between decanter cake and 84 other selected agricultural waste based carbonaceous adsorbents
4.7 Pseudo-first-order and pseudo-second-order kinetic model 88. parameters for Cd2 , Cu2 and Pb2 adsorption onto PDC500
xlii
Table Title Page
4.8 Comparison of pseudo second order kinetic parameter of decanter 91 cake with other selecting waste based adsorbents
4.9 Thermodynamic parameters for adsorption of Cd2+, Cu2+ and Pb2+ 93 onto pyrolized decanter cake
4.10 Selectivity of particular metal ion in multi ion mixture system 96
4.11 Electronegativities, hydrated ionic radius and hydration energies of 98 Cd2 , Cu2 , and Pb2 ion
4.12 Langrnuir and Freundlich parameters for adsorption of Cd2 , Cu2 , 101 and Pb2 onto activated decanter cake
4.13 Pseudo first order and seudo second order kinetic parameters for 104 adsorption of Cd2 , Cu , and Pb2 onto activated decanter cake
4.14 Thermodynamic parameters of andsorption of Pb 2 , Pb2 , and Pb2 109 onto inactivated and activated decanter cake
4.15 Design parameter of single stage batch adsorption for Pb2 removal 110
4.16 Design parameter of multiple-stage batch adsorption for Pb2 111 removal
4.17 Design parameter of single stage continuous adsorption for Pb 2 112 removal
4.18 Design parameter of three stages continuous counter current 113 adsorption system for lead removal
LIST OF FIGURES
Figure Title Page
2.1 Average value of waste generation rate (per ton FFB) 12
2.2 Diagram of biosorption mechanism 29
2.3 Typical plot of initial solution Ph vs adsorption capacity of metal ion 31
2.4 Isotherm showing concentration variables for a transition from 33 (c'1, n') to (c" , n"1 )
2.5 Plot of laboratory data for Langmuir isotherm (a) C. VS qe, 34 and (b) Ce vs Ce/qe
2.6 Log-log plot of Freundlich isotherm model 35
2.7 Linear plot of pseudo first (a) and second order (b) models for 41 adsorption kinetic
2.8 Linear plot of In KdVS 1/T 44
2.9 Single stage batch adsorption 51
2.10 Determination of adsorption capacity of adsorbent for single stage 52 batch mode using Langmuir plot
2.11 Double stages batch adsorption 53
2.12 Single stage continuous adsorption 54
2.13 Multistage countercurrent adsorption 55
2.14 Schematic design of an atomic absorption spectrometry 56
2.15 Typical calibration curve of AAS analysis 57
4.1 Plot of TGA (a), derivative (b) 77
4.2 SEM micrographs of PDC 300 (a), PDC 500 (b), PDC 700 (c), and ash (d) 79
4.3 EDX spectrum for PDC300 (a), PDC500 (b), PDC700 (c) and ash (d) 81
4.4 BET plot 84
4.5 Equilibrium time for Cd2 , Cu2 and Pb2t 86
4.6 Effect of carbonization temperature in adsorption of Cd2 , Cu2 and Pb2 onto carbonized decanter cake 87
xiv
xv
Figure Title Page
4.7 Effect of initial Ph in the adsorption of Cd2+ and Cu2+ onto PDC600 and Pb2+ onto PDC500 88
4.8 Adsorption isotherm for Cd2+ onto PDC 600 (a), plot of linearized Langmuir model (b), and plot of linearized-Freundlich model (c) 90
4.9 Adsorption isotherm for Cu2 onto PDC 600 (a), plot of linearized Langmuir model (b), and plot of linearized-Freundlich model (c) 91
4.10 Adsorption isotherm for Pb2 onto PDC 500 (a), plot of linearized Langmuir model (b), and plot of linearized-Freundlich model (c) 92
4.11 Desorption of Cd2 , Cu2 and Pb2 ions from decanter in different concentrations of HC1 solution 94
4.12 Plot of desorption efficiency (%) vs. time 95
4.13 Plot of data experiment, q vs. t 98
4.14 Plot of pseudo-first-order (a) and pseudo-second-order (b) kinetic models for adsorption of Cd2 , Cu2 and Pb2 onto PDC500 99
4.15 Correlation of temperature and metal ion uptake for adsorption of Cd2 , Cu2 and Pb2 onto PDC500 101
4.16 Plot of In Kd vs. lIT for Cd2 , Cu2 and Pb2 adsorption onto decanter cake 101
4.17 Adsorption uptake of Cd onto PDC 500 in single, binary and ternary system vs. adsorption time 103
4.18 Adsorption uptake of Cu onto PDC 500 in single, binary and ternary system vs. adsorption time 104 104
4.19 Adsorption uptake of Pb onto PDC 500 in single, binary and ternary system vs. adsorption time. 104
4.20 Langmuir and Freundlich adsorption isotherm models for Cd2 adsorption onto H3PO4 (A-prefix) and ZnC12 activated (Z-prefix) decanter cake 107
4.21 Langmuir and Freundlich adsorption isotherm models for Cu2 adsorption onto H3PO4 (A-prefix) and ZnC12 activated (Z-prefix) decanter cake 107
4.22 Langmuir and Freundlich adsorption isotherm models for Pb2 adsorption onto H3PO4 (A-prefix) and ZnC12 activated (Z-prefix) decanter cake 108
4.23 Plot of kinetic data for Cd2 (a), Cu2 (b), and Pb2 (c) adsorption onto PDC500, ADC and ZDC 109
Figure Title
4.24 Linearized plot of pseudo first order kinetic model for Cd 2 (a), Cu2 (b), and Pb2 (c) adsorption onto PDC500, ADC and ZDC 112
4.25 Linearized plot of pseudo second order kinetic model for Cd 2 (a), Cu2 (b), and Pb2 (c) adsorption onto PDC500, ADC and ZDC 113
4.26 Plot of In Kd vs. l/T for Cd2 adsorption onto PDC500, ADC and ZDC 114
4.27 Plot of in Kd vs. lIT for Cu2 adsorption onto PDC500, ADC and ZDC 115
4.28 Plot of in Kd vs. l/T for Pb2 adsorption onto PDC500, ADC and ZDC 115
4.29 Mass balance of three stages continuous counter current adsorption 119
xvi
Page
LIST OF SYMBOLS
Ce equilibrium concentration of metal ions in solution
c1 concentration of adsorbate in solution (linear isotherm)
F fluid flow rate
ki first order rate constant
k2 second order rate constant
Kd equilibrium constant
KF Freundlich constant
K1 adsorption constant (linear isotherm)
KL affinity constant of Langmuir isotherm
n intensity of adsorption constant (Freundlich isotherm)
n1 concentration of adsorbate in adsorbent (linear isotherm)
q amount of metal ion adsorbed per unit weight adsorbent
qe amount of metal ion adsorbed per unit weight adsorbent at equilibrium
qm maximum adsorption capacity of the adsorbent
R ideal gas constant
R2 correlation coefficient
S selectivity
T temperature
t adsorption time
V fluid volume
W adsorbent weight/flow rate
AG Gibbs free energy change
till enthalpy change
AS entropy change
xvii
LIST OF ABBREVIATIONS
AAS Atomic Absorption Spectrometry
BET Brunauer-Emmer-Teller
BOD Biological oxygen demand;
CFC Chiorofluorocarbon
CPO Crude palm oil
CST Continuous settling tank
DOE Department of Environment
EDX Energy dispersive X-ray fluorescence
EEA European Environmental Agency
EFB Empty fruit bunch
EPA Environmental Protection Agency
ESCAP Economic and Social Commission for Asia and the Pacific