^ 4 
C O L O U R R E M O V A L F R O M T E X T I L E E F F L U E N T 
U S I N G 
A G R I C U L T U R A L W A S T E A S A D S O R B E N T S 
MASTER OF SCIENCE 
ODdlVERSITV OF MOBAYUW/A, SRI LAITOA 
MORATUWA 
P.A.JAYASINGHE 
Univers i ty o f M o r a t u w a 
1111111 
UNIVERSITY OF MORATUWA 
MARCH 2006 
85386 
C O L O U R R E M O V A L F R O M T E X T I L E E F F L U E N T 
U S I N G 
A G R I C U L T U R A L W A S T E A S A D S O R B E N T S 
By 
P.A.JAYASINGHE 
THIS THESIS WAS SUBMITTED TO THE 
DEPARTMENT OF CHEMICAL AND PROCESS ENGINEERING 
OF THE UNIVERSITY OF MORATUWA 
IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE 
DEGREE OF MASTER OF SCIENCE 
DEPARTMENT OF CHEMICAL AND PROCESS ENGINEERING 
UNIVERSITY OF MORATUWA 
MORATUWA 
SRI LANKA 
MARCH 2006 
DECLARATION 
I certify that this thesis does not incorporate without acknowledgement any material 
previously submitted for a degree or diploma in any university and to the best o f my 
knowledge and belief it does not contain any material previously published, written or 
orally communicated by another person except, where due reference is made in the 
text. 
P.A.Jayasinghe 
05/8012 
Certified by 
Supervisor 
ACKNOWLEDGEMENT 
From the very beginning I would like to offer my grateful thanks to Dr. (Mrs). Padma 
Amarasinghe, Senior Lecturer, Department of Chemical & Process Engineering, 
University o f Moratuwa, who guided and supervised me as my supervisor an excellent 
way through out the research. Then I must offer my sincere thanks to Dr. 
(Ms).Maneesha Gunesekara, Senior Lecturer, Department o f Chemical & Process 
Engineering, University o f Moratuwa, who guided me in all respect being my co 
supervisor. 
Special thank goes to the Dr. Suren Wijekoon and Dr. Shantha Walpolage, Senior 
Lecturer, Department o f Chemical & Process Engineering, University o f Moratuwa, 
for the valuable comments and suggestions given, as my progress review committee 
members. Prof. Aj i th De Alwis, Head o f the Chemical & Process Department and all 
the lecturers of the Department of Chemical & Process Engineering, University of 
Moratuwa, who helped me in various ways to complete this successfully, must be 
specially mentioned. 
Then I am very much grateful to the University Research Grants for funding my 
research project. 
Non academic staffs o f the Environmental Engineering and Energy Engineering lab, 
Department o f Chemical & Process Engineering, specially Dinusha, Saranelis and 
Lalith and reminded wi th heartful of thanks for their support given me in various 
occasions. 
I warmly remind my beloved parents, sister, brother and Aruna for all the 
encouragement and the support given me as usual. Without their help this effect would 
have not been success. 
Finally, I would like to thanks all postgraduate students o f the Department of 
Chemical & Process Engineering, specially Malka, Oshadi, Gayan, Yashodini, 
Savitha, Thanuja and Chinthaka who were with me and gave the best support me to 
successful this event by making the research period pleasant and enjoyable. 
CONTENTS 
Acknowledgement 
List of Tables 
List of Figures 
List of Annexures 
Abbreviations 
Abstract 
CHAPTER 1: INTRODUCTION 
1.1 Introduction 
1.2 Problems of textile effluents 
1.3 Textile effluent treatments 
1.4 Objectives of the research 
CHAPTER 2: LITERATURE REVIEW 
2.1 Methods of dye house effluent treatment 
2.2 Adsorption as the best option 
2.3 Production techniques of adsorbents 
2.3.1 Chemical activation 
2.3.2 Steam activation 
2.4 History of adsorption 
2.5 Theory of adsorption 
2.5.1 Adsorption kinetics 
2.5.2 Adsorption equilibria 
2.5.2.1 Langmuir adsorption isotherm 
2.5.2.2 Freundlich adsorption isotherm 
2.5.3 Adsorption VS other separation processes 
2.5.4 Modes of operations 
2.5.4.1 Single stage operation 
2.5.4.2 Multistage crosscurrent operation 
2.5.4.3 Multistage countercurrent operation 
2.5.4.4 Fixed bed adsorption operation 
2.6 Bed depth service time (BDST) model 
2.7 Previous literature on adsorption 
ii 
2.7.1 Effect o f surface area on adsorption 25 
2.7.2 Effect o f pH on adsorption 26 
2.7.3 Effect o f other properties on adsorption 27 
2.7.4 Adsorption isotherms 28 
2.7.5 Batch processes Vs fixed bed processes 29 
2.7.6 BDST model 30 
CHAPTER 3: METHODOLOGY 
3.1 Adsorbates 37 
3.2 Adsorbents 37 
3.3 Analysis 38 
3.4 Batch experiments 39 
3.4.1 Effect of adsorbent dosage 39 
3.4.2 Effect o f pH 40 
3.4.3 Adsorption kinetics 40 
3.4.4 Effect o f particle size 40 
3.4.5 Effect o f temperature 40 
3.4.6 Adsorption isotherms 40 
3.5 Packed bed experiments 41 
3.6 Real textile effluent treatments 43 
CHAPTER 4: RESULTS AND DISCUSSION 
4.1 Effect o f adsorbent dosage 44 
4.2 Effect o f pH 48 
4.3 Effect o f particle size 49 
4.4 Adsorption kinetics 51 
4.5 Effect o f temperature 54 
4.6 Adsorption isotherms 55 
4.7 Packed bed studies 58 
4.8 Effect o f the initial dye concentration on the breakthrough curves 62 
4.9 Effect o f the f low rate on the breakthrough curves 63 
4.10 Effect o f bed height on breakthrough curve 64 
4.11 Effect o f adsorbent particle size on breakthrough curve 66 
4.12 Adsorption models 67 
i i i 
4.12.1 BDST with variation in flow rate 
4.12.2 BDST with variation in dye concentration 
4.13 Real textile wastewater treatment 
67 
68 
70 
CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 
5.1 Conclusions 71 
5.2 Recommendations 72 
REFERENCES 74 
ANNEXURES 
4 
y 
iv 
LIST OF TABLES 
Table 2.1 Comparison of low cost adsorbent performance wi th GAC 24 
Table 2.2 BET surface area for Rice Husk based Activated carbon prepared 
by steam treatment 25 
Table 2.3 Surface area of the pyrolysed, activated and raw guava seeds 25 
Table 2.4 Effect of temperature on the adsorption capacity 27 
Table 2.5 Types o f isotherms 28 
Table 2.6 Previous literature on adsorption 31 
Table 3.1 Chemical Properties of adsorbents 38 
Table 3.2 Experimental conditions of the packed bed column tests 42 
Table 4.1 Colour removal Efficiencies of various adsorbents 46 
Table 4.2 Comparison o f the First order and Second order adsorption rate 
constants, Cibacron Blue dye concentration 50 mg/1, pH 2-3, 
equilibrium time 4 hrs at 30 °C 53 
Table 4.3 Linear regression data for Freundlich and Langmuir isotherms 
on dye removal using various types o f adsorbents 56 
Table 4 . 4 Comparison of bed and batch adsorption capacity 61 
Table 4.5 BDST plots data for various f low rates 68 
Table 4.6 BDST plots data for various initial dye concentrations 69 
Table 4.7 Qualities of wastewater and treated water 70 
v 
LIST OF FIGURES 
Figure (2.1) Single stage adsorption 14 
Figure (2.2) Two stage crosscurrent adsorption 16 
Figure (2.3) Countercurrent multistage adsorption 18 
Figure (2.4) The adsorption wave 19 
Figure (2.5) Breakthrough curves 21 
Figure (2.6) pH studies on Acid Blue 29 26 
Figure (2.7) pH studies on Basic Blue 9 26 
Figure (2.8) Adsorption kinetics o f AWC-Dye 27 
Figure (2.9) BDST plot for various f low rates for 
steamed activated carbon by saw dust 30 
Figure (2.10) BDST plot for various dye concentrations for 
steamed activated carbon by saw dust 30 
Figure (3.1) Molecular structure of Cibacron Blue FR Dye 37 
Figure (3.2) Batch experimental setup 39 
Figure (3.3) Schematic presentation of the packed bed adsorption setup 41 
Figure (3.4) Experimental packed bed adsorption unit 41 
Figure (4.1) Effect of HC1 treated adsorbent dosage on the adsorption 
of cibacron blue Co 50 mg/1, pH 2-3, Particle size 710 Micron 45 
Figure (4.2) Effect o f ZnCb treated adsorbent dosage on the adsorption 
o f cibacron blue Co 50 mg/1, pH 2-3, Particle size 710 micron 45 
Figure (4.3) Change o f microscopic structure due to chemical activation 47 
Figure ( 4 . 4 ) Effect of pH on % removal o f Cibacron blue adsorbed on 
various HC1 treated adsorbents 48 
Figure (4.5) Effect o f pH on % removal o f Cibacron blue adsorbed on 
various ZnCb treated adsorbents 48 
Figure (4.6) Kinetic studies for various Particle sizes of HC1 treated coir dust 
at 30 °C, Co 50 mg/1, pH 2-3 50 
Figure (4.7) Kinetic studies for various Particle sizes o f HC1 treated tea waste 
at 30 °C, Co 50 mg/1, pH 2-3 50 
Figure (4.8) Kinetic studies for various types of HC1 treated adsorbents 
at 30 °C, Co 50 mg/1, pH 2-3, Particle size 710 micron 51 
Figure (4.9) First order kinetic plot for adsorption o f Cibacron Blue dye on 
various adsorbents at 30°C, Co 50 mg/1, pH 2-3, Particle size 710 micron 53 
v i 
Figure (4.10) Effect o f contact time for the dye removal on HC1 treated coir dust 
at different temperatures. Co 50 mg/1, pH 2-3, Particle size 710 micron 54 
Figure (4.11) Linear Freundlich adsorption isotherms for various types of HC1 
treated adsorbents at 30 °C. Co 50 mg/1, pH 2-3, particle size 710 micron 58 
Figure (4.12) Linear Langmuir adsorption isotherms for various types o f HC1 
treated adsorbents at 30 °C. Co 50 mg/1, pH 2-3, particle size 710 micron 58 
Figure (4.13) Breakthrough curves for various types o f HC1 treated adsorbents 
at 30 °C, Co 50 mg/1, pH 2-3, Particle size 710 micron, Bed heightlO cm, 
Flow rate 20 ml/min 59 
Figure (4.14) Breakthrough curves for various types of ZnCb treated adsorbents 
at 30 °C Co 50 mg/1, pH 2-3, Particle size 710 micron, Bed height 10 cm, 
Flow rate 20 ml/min 59 
Figure (4.15) Normal and Ideal breakthrough curve for HC1 treated Coir Dust 60 
Figure (4.16) Normal and Ideal breakthrough curve for HC1 treated Rice Husk 61 
Figure (4.17) Effect o f various initial dye concentrations Co, for the system; 
packed bed height 10 cm, Flow rate 20 ml/min, HC1 treated Coir Dust 
particle size 710 micron, pH 2-3 62 
Figure (4.18) Effect o f various initial dye concentrations Co, for the system; 
packed bed height 10 cm, Flow rate 20 ml/min, HC1 treated Rice Husk 
particle size 710 micron, pH 2-3 63 
Figure (4.19) Effect o f various f low rates at a bed height 10 cm, pH 2-3, 
Co 50 mg/1, HC1 treated Coir Dust particle size 710 micron 64 
Figure (4.20) Effect o f various f low rates at a bed height 10 cm, pH 2-3, 
Co 50 mg/1, HC1 treated Rice Husk particle size 710 micron 64 
Figure (4.21) Effect o f various bed heights at a Flow rate 20 ml/min, pH 2-3, 
Co 50 mg/1, HC1 treated Coir Dust particle size 710 micron 65 
Figure (4.22) Effect o f various bed heights at a Flow rate 20 ml/min, pH 2-3, 
Co 50 mg/1, HC1 treated Rice Husk particle size 710 micron 65 
Figure (4.23) Effect o f various particle sizes at pH 2-3, Co 50 mg/1, 
Flow rate 20 ml/min, Bed height 10 cm 66 
Figure (4.24) BDST plots for various f low rates 68 
Figure (4.25) BDST plots for various dye concentrations 69 
v i i 
LIST OF ANNEXURES 
1. Calibration curves 
2. Other figures 
3. Experimental data tables 
3.1 Data tables for HC1 treated Coir Dust 
3.2 Data tables for HC1 treated Rice Husk 
3.3 Data tables for HC1 treated Saw Dust 
3.4 Data tables for HC1 treated Tea Waste 
4. Standard limits for the textile effluents 
ABBREVIATIONS 
CD Coir Dust 
RH Rice Husk 
SD Saw Dust 
TW Tea Waste 
GAC Granular Activated Carbon 
PAC Powdered Activated Carbon 
CB Cibacron Blue FR 
LB Lenazan Blue CF 
COD Chemical Oxygen Demand 
LUB Length o f the Unused Bed 
BDST Bed Depth Service Time 
CEA Central Environmental Authority 
v i i i 
ABSTRACT 
The adsorption process is considered as one of the effective methods for colour removal from 
wastewater. In this study a number of low cost adsorbents were investigated in search of an 
alternative to commercial Granular Activated Carbon (GAC) which is an expensive material. 
Utilization of Coir dust, Rice husk, Saw Dust and Tea Waste has been investigated for its 
ability to adsorb dyes from aqueous solutions. The results showed high removals over 80% of 
Cibacron Blue dye by all four chemically treated adsorbents. The ground and sieved 
adsorbents were activated chemically by impregnating with an activation agent. The use of 
hydrochloric acid and zinc chloride were studied as chemical activation agents in this work. A 
hundred percent colour removal efficiency was observed for the system of HC1 treated Coir 
Dust-Cibacron Blue and Coir Dust was identified as the best substitute for GAC. 
The batch experiments showed that the adsorption of dyes increased with the increase in 
contact time and adsorbent dose. Maximum decolourisation of all the dyes was observed at 
acidic pH. It was observed that contact time up to 4 hrs was required for the every adsorbent-
dye system used in this study to attain equilibrium. The adsorption isotherm studies were 
performed on a laboratory scale setup with two different synthetic dye solutions made up of 
two different commercial grade dyes namely, Cibacron Blue and Lenazan Blue. The 
adsorption capacity for coir dust from this study was found to be 65 mg/g. This was as 
effective as GAC while others were less effective than GAC. The Langmuir & Freundlich 
adsorption models were applied to describe the equilibrium isotherms and both these models 
agreed very well with the experimental data obtained in this work. The kinetics of the process 
was also evaluated by the pseudo first order and second order kinetic models. The results 
gathered from these experiments agreed very well with the first order kinetic model. 
Typical S shape breakthrough curves were obtained from packed bed adsorption experiments 
and 92-100% removal of the adsorbate was observed. The column experiments showed that 
decrease in initial concentration of dye solution, adsorbent particle size, flow rate and increase 
in bed depth produced higher breakthrough time with better bed performance. The Bed Depth 
Service Time (BDST) analysis carried out for the dye indicated a linear relationship between 
bed depth and service time. 
An 83% of colour removal and 72% of Chemical Oxygen Demand (COD) removal 
efficiencies were achieved using HC1 treated Coir Dust for the textile wastewater samples 
containing a mixture of various dyes collected from and industrial establishment. 
ix