• Tiada Hasil Ditemukan

INVESTIGATION OF THE USE OF DATE SEED FOR THE REMOVAL OF BORON FROM SEAWATER

N/A
N/A
Protected

Academic year: 2022

Share "INVESTIGATION OF THE USE OF DATE SEED FOR THE REMOVAL OF BORON FROM SEAWATER "

Copied!
24
0
0

Tekspenuh

(1)

INVESTIGATION OF THE USE OF DATE SEED FOR THE REMOVAL OF BORON FROM SEAWATER

BY

MOUSSA MOHAMED AHMED

A dissertation submitted in fulfilment of the requirement for the degree of Master of Science (Biotechnology

Engineering)

Kulliyyah of Engineering

International Islamic University Malaysia

APRIL 2019

(2)

ii

ABSTRACT

Recently boron has been classified as a pollutant of drinking water in many countries.

Boron is harmful to many plants especially sensible plants and human health. Therefore, boron level needs to be decreased to 0.3 mg/L for drinking water and from 0.5 mg/L to 1 mg/L for irrigation water. In this study, various operational parameters are tested in order to determine feasibility of using date seed (or date pit or date stone) to remove boron from seawater. The main objective of this study was to determine boron adsorption potentials of various date seed preparation methods (i.e., powdered, activated, acid treated and oil extracted seed) by batch adsorption process using synthetic boron contaminated water. The process parameters of the best sorbent among the four date seed preparations methods were optimized. The surface characteristics the best sorbent was analysed by using FTIR and SEM. Equilibrium isotherm and kinetic of the best sorbent were determined. The result showed that acid treated date seed were found to possess best sorption for removal of boron from synthetic seawater with 89.18% of removal at neutral pH and room temperature (25°C±2°C). SEM showed that acid treatment on date seed removed the small cavities and cracks on surface of date seed. FTIR illustrates that O-H stretch, amine (C-N) and aromatic (C-C) are involved in adsorption of boron on acid treated date seed. This study follows Freundlich isotherm and pseudo second order with regression value of R2= 0.9853 and 0.9509, respectively.

(3)

iii

ةصلاخ ثحبلا

تم فينصت نوروبلا ارخؤم هرابتعبا ثاولم هايلم برشلا في ديدعلا نم .نادلبلا نوروبلا راض ديدعلل نم تتاابنلا ةصاخو

تتاابنلا ةساسلحا ةفاضلإبا لىإ هرارضإ ةحصب .ناسنلإا كلذل

، بيج ضفخ ىوتسم نوروبلا لىإ مغلم

0.3

/ ترل هايلم

برشلا نمو ممج

0.5

/ ترل لىإ ممج

1

/ ترل هايلم .يرلا في هذه ةساردلا ، تم رابتخا يرياعم ليغشتلا ةفلتخلما نم لجأ

ديدتح ىودج مادختسا روذب

رمتلا وأ(

ةرفح رمتلا وأ رجح )رمتلا ةلازلإ نوروبلا نم هايم .رحبلا ناك فدلها يسيئرلا

نم هذه ةساردلا وه ديدتح ةيناكمإ زازتما نوروبلا ةطساوب روذب رومتلا ةرضلمحا ةدعب قرط قوحسم(

،روذبلا

،طَّشنلما

لجاعلما ضمالحبا روذبلاو

صلختسلما اهنم

)تيزلا ةطساوب ةيلمع زازتملاا يعفدلا نم هايلما ةثوللما نوروبلبا .ايعانطصا تم

ديدتح فورظلا ىلثلما لضفلأ داولما ةزالما نم ينب قرط يرضحتلا ةعبرلأا

.ةفلتخلما تم ليلتح صئاصلخا ةيحطسلا

ةقيرطلل

ةراتخلما مادختسبا

FTIR

و

SEM

. ميرثوزسيا نزاوتلا

ةيكرلحاو تم اهريدقت ةداملل تاذ زازتملاا ثملأا

. ل ترهظأو

جئاتنلا نأ روذب ةلجاعلمارمتلا ايضحم

تققح زازتملاا لضفلأا ةلازلإ نوروبلا نم هايم رحبلا ةيعانطصلاا ةبسنب

ةلازأ تغلب

89.18

٪ في ةجرد ةضوملحا ةديامح ( 7 ) ةجردو ةرارح ةفرغلا ( 25 ةجرد ةيوئم

± 2 ةجرد .)ةيوئم ترهظأو

SEM

نأ ةلجاعلما ةيضملحا ىلع روذب رومتلا تلازإ فيواجتلا ةيرغصلا

قوقشلاو ىلع

حطس روذب .رومتلا حضوي

FTIR

نأ

دادتما

O-H

، ينمأ (

C-N

) ةيرطعلاو (

C-C

) تهماس في زازتما نوروبلا ىلع روذب رمتلا ةلجاعلما .ايضحم عبتت

هذه ةساردلا

isotherm Freundlich

و

order second pseudo

عم ةميق 0.9853

R2

و 0.9509

ىلع،

.لياوتلا

(4)

iv

APPROVAL PAGE

I certify that I have supervised and read this study and that in my opinion, it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Master of Science (Biotechnology Engineering).

………..

Mohammed Saedi Jami Supervisor

………..

Mohamed Elwathig Saeed Co-Supervisor

………..

Md Noor Bin Salleh Co-Supervisor

I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Master of Science (Biotechnology Engineering).

………..

Nassereldeen Ahmed Kabbashi Internal Examiner

………..

Husna Ahmad Tajuddin Internal Examiner

This dissertation was submitted to the Department of Biotechnology Engineering and is accepted as a fulfilment of the requirement for the degree of Master of Science (Biotechnology Engineering).

………..

Nor Fadhillah binti Mohamed Azmin

Head, Department of

Biotechnology Engineering This dissertation was submitted to the Kulliyah of Engineering and is accepted as a fulfilment of the requirement for the degree of Master of Science (Biotechnology Engineering).

………..

Ahmad Faris Ismail

Dean, Kulliyyah of Engineering

(5)

v

DECLARATION

I hereby declare that this dissertation is the result of my own investigations, except where otherwise stated. I also declare that it has not been previously or concurrently submitted as a whole for any other degrees at IIUM or other institutions.

Moussa Mohamed Ahmed

Signature ... Date ...

(6)

vi

Copyright

INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

DECLARATION OF COPYRIGHT AND AFFIRMATION OF FAIR USE OF UNPUBLISHED RESEARCH

INVESTIGATION OF THE USE OF DATE SEED FOR THE REMOVAL OF BORON FROM SEAWATER

I declare that the copyright holders of this dissertation are jointly owned by the student and IIUM.

Copyright © 2019 Moussa Mohamed Ahmed and International Islamic University Malaysia. All rights reserved.

No part of this unpublished research may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without prior written permission of the copyright holder except as provided below

1. Any material contained in or derived from this unpublished research may be used by others in their writing with due acknowledgement.

2. IIUM or its library will have the right to make and transmit copies (print or electronic) for institutional and academic purposes.

3. The IIUM library will have the right to make, store in a retrieved system and supply copies of this unpublished research if requested by other universities and research libraries.

By signing this form, I acknowledged that I have read and understand the IIUM Intellectual Property Right and Commercialization policy.

Affirmed by Moussa Mohamed Ahmed

……..……….. ………..

Signature Date

(7)

vii

ACKNOWLEDGEMENTS

All praises are due to Almighty, merciful, for having granted me and all my family a health and happiness without fault. I extend my sincere thanks to my Government, who sponsored me during my Master's degree and to my family, who was with me, whatever the circumstances.

I am very grateful to my supervisor Associate Professor Dr Mohammed Saedi Jami who has had plenty of time to teach me, correct me and encourage me to work hard. May Allah reward him abundantly. I also thank my two co-supervisors Associate Professor Dr Mohamed Elwathig Saeed and Prof. Emeritus Dato' Wira Ir. Dr. Md Noor Bin Salleh for helping me a lot in my research.

I wish to acknowledge the contribution of my senior brother Mohamed Ngabura and my sister Amina Mohamed Ali for their advice and help.

I would like to express my deepest gratitude to my fiancée for all the efforts she has made so that I can finish my Master’s degree with honours.

(8)

viii

TABLE OF CONTENTS

Abstract ... ii

Abstract in Arabic ... iii

Approval Page ... iv

Declaration ...v

Copyright ... vi

Acknowledgements ... vii

List of Tables ... xi

List of Figures ... xii

List of Abbreviations ...xiv

List of Symbols ... xv

CHAPTER ONE: INTRODUCTION ...1

1.1 Background of the Study ...1

1.2 Statement of the Problem ...3

1.3 Research Objectives ...4

1.4 Research Methodology...4

1.5 Research Scope ...5

1.6 Thesis Organisation ...5

CHAPTER TWO: LITERATURE REVIEW ...7

2.1 Overview ...7

2.2 Boron in Environment ...8

2.2.1 Physico-Chemical Properties Of Boron ...8

2.2.2 Health Effects of Boron ...8

2.2.3 Boron Analysis Methods ...9

2.2.3.1 Boron Determination by Inductively Coupled Plasma Icp ...9

2.2.3.2 Boron Determination by Curcumin Method ... 10

2.2.3.3 Boron Determination by H-Azomethine Spectrophotometer 11 2.2.3.4 Dispersive Liquid-Liquid Microextraction ... 12

2.3 Biosorption Process ... 12

2.4 Methods for Boron Removal ... 14

2.4.1 Reverse Osmosis Membrane ... 14

2.4.2 Boron Removal by Activated Carbon ... 17

2.4.3 Boron Removal by Ion Exchange ... 21

2.5 Date Palm ... 23

2.5.1 Date Palm Production ... 24

2.5.2 Date Palm Varieties and Its Chemical Composition ... 25

2.6 Date Seed ... 27

2.6.1 Chemical Composition of Date Pits... 27

2.6.2 Date Seed as Biosorbent ... 28

2.7 Biosorption Isotherms ... 32

2.7.1 Langmuir Isotherm ... 33

2.7.2 Freundlich Isotherm ... 35

2.7.3 BET Isotherm ... 36

2.8 Adsorption Kinetic ... 37

(9)

ix

2.9 Adsorbent Characterisation ... 41

2.10 Research Gap ... 41

CHAPTER THREE: MATERIALS AND METHODS ... 43

3.1 Biosorption Process ... 43

3.2 Chemical and Reagents ... 44

3.2.1 Preparation of Biosorbent ... 45

3.2.1.1 Preparation of Raw Date Seed ... 45

3.2.1.2 Activated Carbon from Date Seeds ... 45

3.2.1.3 Date Seed Without Oil ... 45

3.2.1.4 Acid Treated Date Seed ... 46

3.3 Instrumentation and Apparatus ... 47

3.4 Boron Sorption Studies ... 47

3.5 Batch Experiments with Acid Treated Date Seed ... 48

3.5.1 Effect of Solution pH ... 48

3.5.2 Effect of Contact Time ... 48

3.5.3 Effect of Liquid to Solid Ratio ... 49

3.6 Optimization Using Rsm ... 49

3.7 Characterisation of Date Seed ... 50

3.7.1 Ftir Analysis ... 50

3.7.2 Scanning Electron Microscope (Sem) ... 50

3.8 Equilibrium Isotherm Study ... 51

3.9 Kinetic Study ... 51

CHAPTER FOUR: RESULTS AND DISCUSSION ... 53

4.1 Calibration Curve ... 53

4.2 Screening of Potentials of Various Date Seed Preparation Methods ... 53

4.3 Batch Experiments wth Acid Treated Date Seed ... 54

4.3.1 Effect of pH on Adsorption ... 54

4.3.2 Effect of Liquid to Solid Ratio on Adsorption ... 55

4.3.3 Effect of Contact Time on Adsorption... 57

4.4 Design Of Experiment ... 57

4.5 Use Of Seawater For Validation ... 62

4.6 Characterization of Date Seed ... 63

4.6.1 Ftir ... 63

4.6.2 Scanning Electron Microscope (Sem) ... 66

4.7 Equilibrium Isotherm ... 69

4.7.1 Langmuir Isotherm ... 69

4.7.2 Freundlich Isotherm ... 70

4.7.3 Bet Isotherm ... 71

4.8 Kinetic Study ... 71

CHAPTER FIVE: CONCLUSION AND RECOMMENDATION ... 75

5.1 Conclusion ... 75

5.2 Recommendations ... 76

REFERENCES ... 77

(10)

x

LIST OF TABLES

Table 2.1 Distribution of boric acid H3BO3/H2BO3- as a function of pH. 15 Table 2.2 Commercial SWRO membrane used for boron removal from seawater. 16 Table 2.3 Effectiveness of active materials used to remove boron from Boric acid

water solution in continuous flow system. 18

Table 2.4 Removal of boron from wastewater at 20°C and pH 8.0. 20

Table 2.5 Date palm production in 2003 25

Table 2.6 Chemical composition of date flesh Deglet Nour 26

Table 2.7 Chemical composition of date palm seed. 28

Table 4.1 Design of experiment (DOE) 57

Table 4.2 Analysis of variance for significant model terms 58 Table 4.3 Analysis of variance for selected factorial model 59

(11)

xi

LIST OF FIGURES

Figure 2.1 The calibration graph. 12

Figure 2.2 Distribution of boric acid H3BO3/H2BO3- as a function of pH. 15 Figure 2.3 Amount of adsorbed boron over the dose of activated carbon

impregnating with calcium tartaric acid and mannitol. 19 Figure 2.4 Boron removal from wastewater in function of activated carbon dose. 20 Figure 2.5 Boron adsorption on activated alumina (Al2O3), activated carbon

impregnated with tartaric acid (AC+TA) and mannitol (AC+M) with initial boron concentration 20 mg/L and liquid to solid ratio 1g to 50

cm3 at 20°C and pH 6.0 21

Figure 2.6 The structure of boron selective chelating resin with functional group N-

methyl-D-glucamine (NMDG). 22

Figure 2.7 Binding mechanism by N-methyl-D-glucamine type chelating resin. 23 Figure 2.8 Date production in Arab countries plus Iran and Pakistan for 2008. 24 Figure 2.9 Effect of pH on the removal efficiency of boron 29 Figure 2.10 The effect of contact time on removal of boron 30 Figure 2.11 The effect of date seed dose on boron uptake 31 Figure 2.12 Boron removal efficiency for 24 hours reaction time date seed

with seawater. 32

Figure 2.13 Monolayer Langmuir adsorption 33

Figure 2.14 Langmuir Isotherm 34

Figure 2.15 Freundlich Isotherm 36

Figure 2.16 Multilayers BET adsorption 37

Figure 2.17 BET isotherm model 37

Figure 3.1 Flow chart for bioseperation process of date seed 44

Figure 3.2 Raw date seed 45

Figure 3.3 Activated Date seed 46

Figure 3.4 Oil extracted date seed 46

(12)

xii

Figure 3.5 Acid treated date seed 47

Figure 4.1 Calibration curve 53

Figure 4.2 Removal percentage as function of various preparation methods of date

seeds 54

Figure 4.3 Boron removal efficiency by acid treated date seeds as function of pH 55 Figure 4.4 Boron removal by acid treated date seeds as a function of liquid to solid

ratio 56

Figure 4.5 Boron removal by acid treated date seeds as function of contact time 57

Figure 4.6 Effect of liquid to solid ratio and pH 60

Figure 4.7 Effect of contact time and pH 61

Figure 4.8 Effect of contact time and liquid to solid ratio 62

Figure 4.9 Characterisation of raw date seed using FTIR 64

Figure 4.10 Comparison of functional groups on acid treated date seed (sample 3)

and activated date seed (sample 4) using FTIR 65

Figure 4.11 Function groups of acid treated date seed before adsorption (sample 3

) and date seed after adsorption (sample 1) 66

Figure 4.12 Scanning elelctron microscope of activated date seed 67 Figure 4.13 SEM of acid treated date seed before adsorption 68 Figure 4.14 SEM of acid treated date after boron adsorption 69

Figure 4.15 Linear plot of Langmiur isotherm model 70

Figure 4.16 Freundlich Isotherm 71

Figure 4.17 BET Isotherm 72

Figure 4.18 Pseudo First Order 72

Figure 4.19 Pseudo second order 73

Figure 4.20 Intraparticle diffusion 74

(13)

xiii

LIST OF ABBREVIATIONS

AAS Atomic Absorption Spectroscopy

AC Activated Carbon

ADS Activated Date Seed

ATDS Acid Treated Date Seed BET Brunauer Emmet Teller FTIR Fourier Transform Infrared ICP Inductively Coupled Plasma L/S Liquid to Solid Ratio

M Mannitol

OFDS Oil Free Date Seed PAC Powder Activated Carbon

RDS Raw Date Seed

SEM Scanning Electron Microscope SWRO Seawater Reverse Osmosis

TA Tartaric Acid

UV Ultraviolet

WHO World Health Organization

(14)

xiv

LIST OF SYMBOLS

Ci Initial concentration Ce Equilibrium concentration

qe The amount of solute adsorbate per unit weight of adsorbent solute at equilibrium

qt The amount of solute adsorbate per unit weight of adsorbent solute at time t R2 Regression value

h Initial sorption rate

Q0 Maximum adsorption capacity K Constant

(15)

1

CHAPTER ONE INTRODUCTION

1. CHAPTER ONE: INTRODUCTION

1.1 BACKGROUND OF THE STUDY

The rapid growth of the world's population and industrialization and climate change are the causes of water scarcity. A study on the global assessment of freshwater reveals that nearly four billion people are affected water shortage. Half of this population lives in China and India (Kummu et al., 2016). Hoekstra study shows that many countries are concerned about water scarcity. Djibouti is included in countries facing severe water scarcity throughout the year (Hoekstra, 2016). The lack of fresh water decrease the quality of the drinking water and therefore the whole population of the countries concerned by the lack of water drinks unfit water (Seckler & Barker, 2010). Nowadays, the desalination is one of the alternative methods to provide water basic in hydrological cycle. Recently the desalination method is used more and more and global water from desalination plant is increased two times since 2008 to 2016 (Elimelech & Phillip, 2011). Boron is one of the common contaminants in seawater and is essential for plants and animals. However, acceptable boron level for irrigation of some boron-sensitive plant is 0.5 mg/L. A study on some animals such as mice, rats and rabbits showed that boron could inhibit growth and reproduction of certain animals. Admittedly, man is not immune to the harmful effects of boron, which is manifested in animals. A dose of boron of 15 g to 20 g for adults and 3 g to 5 g for children can be fatal (Kabay, 2010;

Bakirdere, 2010; Kot, 2009; Obispo & Rahman, 2009; Sütçü et al., 2005). Henceforth, boron concentration in drinking water and irrigation water should be 0.3 mg/L, 0.5 mg/L to 1 mg/L respectively, (Kabay et al., 2010).The main objective of this study is to screen adsorption potential of various preparations methods of date seeds. In this study, various

(16)

2

operational parameters are tested in order to determine feasibility of using date seed (or date pit or date stone) to remove boron from seawater. The other objective of this study was to determine boron adsorption potentials of various date seed preparation methods (i.e., powdered, activated, acid treated and oil extracted seed) by batch adsorption process using synthetic boron contaminated water. The process parameters of the best sorbent among the four date seed preparations methods were optimized. The surface characteristics of the best sorbent was analysed by using FTIR and SEM. Conventional methods for removal of boron are reverse osmosis membrane, ion exchange, adsorption/precipitation. Reverse osmosis membrane removes 99% of boron from aqueous solution but removal efficiency depends on type of membrane, pH, temperature. Ion exchange is a good boron removal method and removes 80% to 87%

of boron with the presence of others competitive chemical elements. Moreover, activated carbon is most popular adsorbent for removal of boron from aqueous solution.

However, conventional methods are quite expensive to be applicable. The date seeds are alternative adsorbent for decreasing boron seawater at neutral pH. The date seeds removed 71.1% of boron from seawater at neutral pH. The advantages of the use of date seeds for removal of boron is that date seeds are abundant, non-toxic, eco-friendly and work well at neutral pH (7) ( Parks & Edwards, 2005; Farhat et al., 2013; Güler et al., 2015; Kabay & Bryjak 2015; Kabay, et al., 2010; Xu & Jiang 2008; Miodrag Belosevic, 2014; Kluczka et al., 2007; Xu & Jiang, 2008; Al-Haddabi et al., 2016; Al-Ithari et al., 2014).

(17)

3 1.2 STATEMENT OF THE PROBLEM

Today, almost 4 billion of the world's population is facing water shortage, at least a month in a year. Djibouti is one of the countries to be drown into the problem of water scarcity. People living in countries affected by water scarcity consume dirty water that harms human health. Desalination of seawater is an alternative source of water to combat the scarcity of water. The use of seawater desalination continues to grow in the world (Elimelech & Phillip, 2011; Hoekstra, 2016; Khawaji et al., 2008; Kummu et al., 2016; Schewe et al., 2014; Seckler & Barker, 2010). Boron is one of the main components of seawater. Studies in mice, rats and rabbits have shown that boron has serious consequences in the growth system. In humans, a dose of 3 g to 6 g for children and 15 g to 20 g of boron for adults is fatal. The clinical effects of boron are irritability, convulsions and gastrointestinal disorders, inflammation, congestion, exfoliation of the mucosa, exfoliative dermatitis. For the plant, the boron tolerance of the sensitive plant such as grape is 0.5 mg/L. Therefore, World Health Organization (WHO) has set 0.3 mg/L of boron in drinking water (Bakirdere et al., 2010; Kot, 2009; Parks & Edwards, 2005; Obispo & Rahman, 2009; Sütçü et al., 2005). Conventional methods for removal of boron are reverse osmosis membrane, ion exchange and activated carbon. All of them remove from 80% to 98% of boron but they depend on some parameters like pH, temperature and pressure. Conventional methods are very expensive (Bick & Oron 2015; Kabay & Bryjak 2015; Rahmawati et al., 2012; Chen et al., 2003; Köse et al., 2011; Bick & 2015; Xu & Jiang 2008). The major aim of this work is to determine feasibility of using date seed (or date pit or date stone) to remove boron from seawater.

The other objective of this study was to determine boron adsorption potentials of various date seed preparation methods (i.e., powdered, activated, acid treated and oil extracted seed) by batch adsorption process using synthetic boron contaminated water. The

(18)

4

process parameters of the best sorbent among the four date seed preparations methods were optimized. The surface characteristics of the best sorbent was analysed by using FTIR and SEM. The biomass used in this study is date seeds which are abundant, non- toxic, eco-friendly and very effective and efficiency in adsorption performance of boron at room temperature and neutral pH (Al.Haddabi et al., 2016; Al-Ithari et al., 2014).

1.3 RESEARCH OBJECTIVES

The overall objective of this work is to investigate the use of date seed for the removal of boron from seawater as a pretreatment for reverse osmosis membrane process.

The specific objectives are:

1. To determine boron adsorption potentials of various date seed preparation methods (powdered, activated, acid treated and oil extracted seed) by batch process using synthetic seawater.

2. To optimize the process parameters such as pH, adsorbent dose, mixing time for maximum removal efficacy of the best sorption capacity of date seed in objective (1) using full factorial design and response surface methodology.

3. To investigate the adsorption isotherms and kinetics of the adsorption process.

1.4 RESEARCH METHODOLOGY

The purpose of this study is to put in place a very effective way of removing boron from seawater so that it can become drinkable. It is the use of the date seed which is neither expensive nor rare and which has a very good efficiency of boron adsorption. In this approach, it is necessary to rigorously adjust the parameters affecting the boron

(19)

5

adsorption process. Thus, after the comparison phase of the different adsorbent preparations, the best adsorbent will be used for the optimization of the parameters by using response surface methodology. And the final equilibrium isotherm and kinetic model for this study will be determined.

1.5 RESEARCH SCOPE

The scope of this study is:

1. To investigate adsorption potential of date seed for removal of boron by batch using synthetic seawater prepared in the laboratory.

2. To perform batch biosorption study under the following experimental conditions:

a. Reaction temperature (25°C±2°C) b. Particle size (106 µm)

c. Biosorbent dose (fixed: 10 mg/L, varied: 10 mg/L-80 mg/l) d. Initial boron concentration: (80 mg/L)

e. pH (fixed: 7, varied 2-12)

f. Volume of solution sample (50 mL) g. Agitation speed (fixed: 150 rpm)

1.6 THESIS ORGANISATION

This study is composed of 5 chapters. Chapter 1 provides a brief background of water scarcity around the world and the demand for alternatives for subsidized areas where water scarcity is important. It covers the statement of problem which includes some basis and rational for identification of the research. Chapter 2 consists of the literature review including the deleterious effects of boron and methods for determining the

(20)

6

presence of boron in the environment. Chapter 3 illustrates the materials and methods used for preparation of adsorbent and determine the parameters that influence the boron adsorption process. Chapter 4 covers the results of the experiments that have been done in the previous chapters. Finally, Chapter 5 includes the conclusion and recommendation.

(21)

7

CHAPTER TWO LITERATURE REVIEW

2. CHAPTER TWO: LITERATURE REVIEW

2.1 OVERVIEW

Adsorption is a purely superficial process in which atoms and molecules are accumulated preferably on the surface of a solid (interface), thus after adsorption the concentration of atoms or molecules on the surface of adsorbent is greater than bulk concentration (Drew Myers, 1999). Molecules that accumulate on the solid surface are called adsorbate and the solid surface that adheres to the molecule on its surface is called adsorbent. The adsorbent is designed in an extremely porous form and has a large surface area to retain the molecule on its surface. However, adsorption is possible for two reasons, the first being that the adsorbate is poorly soluble in the solution and the second is that the adsorbate has a high affinity for the adsorbate only in the liquid. There are two types of adsorption depending on the nature of the bond between adsorbent and adsorbate (Drew Myers, 1999). First there is the physisorption which implies a weak but possible Van der Waals force at a temperature inferior the boiling point of the adsorbate. If the temperature increases, the processof physical-sorption decreases (Drew Myers, 1999; G.H.Findenegg, 1992). The second type of adsorption is the chemisorption that occurs when the adsorbent and the adsorbate are fixed by chemical force. Thus, chemisorption occurs at all temperatures and increases with temperature (Drew Meyrs, 1999). Nowadays, inexpensive adsorbent is used in wastewater treatment (P.S. Kumar & K. Kirthika, 2009).

(22)

8 2.2 BORON IN ENVIRONMENT

In the last decade boron is considered as a potential contaminant that must be regulated but there are important points such as boron chemistry, boron in environment, health effects of boron, existing guideline to know before that regulation is put in place.

2.2.1 Physico-Chemical properties of Boron

First, figuring out of boron chemistry is unavoidable in designing a treatment method to reduce boron concentration in environment. Moreover, atomic number of boron is 5, it is located on IIIA of periodic table but it is often bound to hydrogen and oxygen to compensate electron deficient. In fact, boron has three or four coordination number as it is shown in boric acid (B3OH3) and tetrafluoroboride anion BF4-. There are two isotopes of boron existing naturally , occur often in 20:80 ratio and type of isotope ratio might related to the source of water sources (Parks & Edwards, 2005). Boron occurs naturally in the form of boric acid, borate ion and borosilica. Boric acid is converted into ion borate in aqueous following this equation:

B(OH)3 + H2O ↔ B(OH)-4 +H+ (2.1) Thus, dissociation of boric acid to ion borate is quite related to the pH. In pH greater than pH 9.24 the ion borate B (OH) 4-is dominant and pH smaller than pH 9.24 boric acid H3BO3 is dominant.

2.2.2 Health Effects of Boron

Some experiments conducted on mice, rats and rabbit to evaluate the boron toxicity have revealed that boron is not mutagenic and carcinogenic but it affected exactly the development and reproduction of these animals. Thus, the fatal toxicity of boron includes prenatal mortality, reduce foetal body weight, cardiovascular and central

(23)

9

nervous system even malformation of eyes, cardiovascular system and axial skeleton.

It has been proven empirically that boron inhibits the sperm production at dose of 3 g/L, 4.5 g/L and 6 g/L of boron (Bakirdere et al.,2010). However, the results of animal studies suggest that humans are not immune to the harmful problems of the boron element (Bakirdere et al., 2010). Thus, the presence of boron in our dietary has an impact on plasma or serum concentration of certain hormones namely calcitonin, 17b- estradiol, 25-hydroxycholecalciferol and triiodothryronine (Kot, 2009). It has been observed from accidental poisoning that the acute lethal dose of boric acid is 3000-6000 mg for infants and 15,000 till 20,000 mg for adults. Clinical effects include irritability, seizures and gastrointestinal disturbances. There have also been reports of inflammation, congestion, exfoliation of the mucosa, exfoliative dermatitis, findings of cloudy swelling and granular degeneration of renal tubular cells and oedema. Moreover the Clinical symptoms of boron toxicity have been observed in the range of 100 till 55500 mg relying on age/body weight (Bakirdere et al., 2010).

2.2.3 Boron Analysis Methods

2.2.3.1 Boron determination by inductively coupled plasma ICP

In overall, Inductively coupled plasma-optical emission spectrometry (ICP-OES) is applied for determining accurate boron concentration (Flores & Muller, 2015). The Inductively Coupled Plasma-Atomic Emission Spectrometer used for determining boron concentration in black tea, tea fruit and fruit brew has some properties such as radial torch equipped with argon, power of 1100 kW, observation height 15 mm, plasma gas flow 12 L/min, sheet gas flow 0 L/min, nebulizer gas flow 0.75 L/min, photomultiplier voltage 800 V, sample uptake rate 1.0 mL/L, integration time 1.0 s and sample time delay 30 s. Thus, it has been repeated three times the measurement of boron

(24)

10

for aiming accurate result. The wavelength applied for boron detection were B 208.959 nm, B 249.678 nm, and B 249.773 nm (Zioła-Frankowska et al., 2014).

2.2.3.2 Boron determination by curcumin method

The curcumin reaction with boric acid resulted in a red coloring and thus it becomes one of the best ways to detect the presence of boron in a medium. For this reason, this method is widely applied in the field of reaction materials and agriculture. The curcumin reaction with boric acid takes place when the curcumin molecule is protonated by a strong acid. Therefore, this protonated form of curcumin is unstable and decomposes under heat. Thus, the evaporation process of boron-curcumin assembly requires that:

1. The acidity increases during evaporation till curcumin is protonated. This is showed by transition of colour from yellow to deep red.

2. The protonation of curcumin occurs at certain level in certain condition during evaporation for avoiding early decomposition.

Moreover, it has been suggested below for formation of boron-curcumin:

1. Temperature in the range 55°C to 100°C used for evaporation.

2. Only strong acid which can protonate the curcumin are applied to generate complex curcumin-boron.

3. Oxalic acid must be avoided during the formation of complex curcumin- boron.

4. Acetic acid is preferably applied instead of alcohol in detection of boron using curcumin. Acetic acid application reduce boron evaporation.

The procedure of boron-curcumin complex starts by adding aqueous solution of boric acid or methyl borate in methanol solution to a platinum dish or small polyethylene beaker containing 1 mL per 10 per cent sodium hydroxide solution. Then

Rujukan

DOKUMEN BERKAITAN

5.3 Experimental Phage Therapy 5.3.1 Experimental Phage Therapy on Cell Culture Model In order to determine the efficacy of the isolated bacteriophage, C34, against infected

In examining the effect of sonication cycle time on the effectiveness of in-situ ultrasonication in increasing the rate of filtration, experiment was initially conducted

1) To optimize the operating parameters (activation temperature, activation time and chemical impregnation ratio IR) in the preparation of mesoporous activated carbons

Taraxsteryl acetate and hexyl laurate were found in the stem bark, while, pinocembrin, pinostrobin, a-amyrin acetate, and P-amyrin acetate were isolated from the root extract..

Adsorption Kinetics and Equilibrium of Methylene Blue from Aqueous Solutions Using Phosphoric Acid Treated Date Seeds. In this study, the adsorbent material used to adsorb

With this commitment, ABM as their training centre is responsible to deliver a very unique training program to cater for construction industries needs using six regional

This project revolved on finding the most optimum parameters for preparation and characterization of activated carbon from rubber seed shell by manipulating

Hurst et al presented a graphene pressure sensor based on an array of suspended circular graphene membranes over holes (diameter of 3µm) in silicon dioxide on degenerately