The Determination of Heavy Metals in Tap Water

THE DETERMINATION OF HEAVY METALS IN TAP WATER BY USING ATOMIC ABSORPTION SPECTROSCOPY (AAS)

NOR HASBIYANA ABD WAHAB

BACHELOR OF SCIENCE ( Hons. ) CHEMISTRY FACULTY OF APPLIED SCIENCES UNIVERSITY TEKNOLOGY MARA

NOVEMBER 2008

THE DETERMINATION OF HEAVY METALS IN TAP WATER BY USING ATOMIC ABSORPTION SPECTROSCOPY (AAS)

NOR HASBIYANA ABD WAHAB

Final Year Project Report Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Science (Hons.) Chemistry In the Faculty of Applied Sciences Universiti Technology MARA

NOVEMBER 2008

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ACKNOWLEDGEMENTS Upon completion of this project, I would like to express my gratitude to many parties. My heartfelt thanks goes to my supervisor, Hajjah Mashiah Domat Shaharudin for her spending time, advice and guidance throughout the work involved to complete this project.

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I would like to express my gratitude also to my co supervisor, Nesamalar Kantasamy for opinion and knowledge shared. Thank you for S. Mariam Sumari, lecturer of environment pollution control as a second examiner for spending time marked and corrected my final report project and also critics and suggestions to complete this report. Thank also for all of the laboratory staffs for helped me during running this project and to my friends who had helped me directly or indirectly during this project work. My special thanks from the bottom of my heart goes to my parents, brothers and sisters for their understanding, encouragement, moral and financial support and emphasis on the value of education. Not forgetting my thanks goes to the head of programme, Assoc Prof Badariah Abu Bakar for advice and motivation. Lastly, I would like to thank those who had contributed either directly or indirectly for completion this study.

Nor Hasbiyana Abd Wahab

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TABLE OF CONTENTS Page ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF ACRONYMS AND ABBREVIATIONS ABSTRAK ABSTRACT

iii iv v vi vii viii ix

CHAPTER 1 : INTRODUCTION 1.1 Background 1.2 Significance of study 1.3 Objectives of study

1 5 5

CHAPTER 2 : LITERATURE REVIEW 2.1 Introduction 2.2 The study of heavy metals

7 7

CHAPTER 3 : METHODOLOGY 3.1 Background 3.2 Site Sampling 3.3 Materials 3.3.1 Sample 3.3.2 Chemicals 3.3.3 Apparatus 3.3.4 Instrument 3.4 Methods 3.4.1 Sample Collection 3.4.2 Sample Preparation 3.4.3 Sample Analysis

12 12 14 14 14 14 14 15 15 15 16

CHAPTER 4 : RESULT AND DISCUSSION 4.1 Determination safety level of samples 4.2 Determination of the most and the least concentrated heavy metal 4.3 Determination of site sampling affect the concentration of heavy metals

17 17 19 21

CHAPTER 5 : CONCLUSION AND RECOMMENDATIONS

24

CITED REFERENCES APPENDICES CURRICULUM VITAE

26 28 33

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LIST OF TABLES

Table

Caption

Page

3.41

The list of sample collected according to the site sampling

28

3.42

The concentration of standard solution and its detection limit

29

4.13

The range concentration of heavy metals in the samples

18

4.14

The parameter according to MNDWQS

18

4.15

The parameter MCL for public drinking water supply by US EPA

18

4.31

The comparison between types of site sampling with elements

21

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LIST OF FIGURES

Figure

Page

3.20

Map of Shah Alam and sampling location

13

4.11

Standard calibration curve of standard solution

30

4.12

Graph of concentration heavy metals in samples plotted

31

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LIST OF ACRONYMS AND ABBREVIATIONS

AAS

:

Atomic Absorption Spectroscopy

FAAS

:

Flame Atomic Absorption Spectroscopy

AES

:

Atomic Emission Spectroscopy

MIP AES

:

Microwave-induced plasma atomic emission spectroscopy

ICP OES

:

Inductively Coupled Plasma

MCL

:

Maximum Concentration Level

US EPA

:

United State Environment Protection Agency

MNDWQS

:

Malaysian National Drinking Water Quality Standards

EWG

:

Environment Working Group

WHO

:

World Health Organization

Cd

:

Cadmium

Pb

:

Lead

Cu

:

Copper

Hg

:

Mercury

As

:

Arsenic

Al

:

Aluminium

Zn

:

Zinc

Fe

:

Iron

Co

:

Cobalt

Mn

:

Mangan

Ni

:

Nickel

L

:

liter

km

:

kilometer

ml

:

milliliter

HNO3

:

Nitric Acid

WHO

:

World Health Organization

RO

:

Reverse Osmosis

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ABSTRACT

THE DETERMINATION OF HEAVY METALS IN TAP WATER SAMPLE BY USING AAS

Tap water that becomes the main source of water that is used by people should be evaluated for the safety level whether it is free from the contamination of bacteria or heavy metals. Most of the studies that have been done that use tap water samples showed that heavy metals really exist in tap water samples. This study focuses on tap water because it is widely used and it became the basic need for human being. The evaluation of the safety level of tap water is very important. Hence, this study is done to achieve a few objectives , that are to determine the concentration of heavy metals in tap water samples whether they are safe or not according to the parameter and standard of water quality for heavy metals by MNDWQS and US EPA. So as to determine the concentration of each element in order to identify which is the most concentrated and vice versa. This study also compares the level of heavy metals’ concentration according to the types of site sampling from industrial, agricultural and housing areas. By using AAS, the result of this study showed that most of the samples contain heavy metals. This study has achieved all of the objectives whereby the results of this study showed that the levels of most of heavy metals’ concentration exceed the limit for level of the water quality. This study also proves that the location of water might influenced the concentration of heavy metals in tap water sample.

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ABSTRAK

PENENTUAN LOGAM– LOGAM BERAT DALAM SAMPEL AIR PAIP DENGAN MENGGUNAKAN AAS Air paip yang menjadi sumber utama kegunaan air bagi manusia perlu di nilai tahap keselamatan penggunaan sama ada telah bebas daripada kandungan bacteria mahupun logam-logam berat. Banyak kajian yang telah di jalankan yang menggunakan sample air mendapati logam berat memang wujud dalam sampel air. Kajian ini menggunakan air paip sebagai sampel kerana ia digunakan secara meluas dan ia merupakan keperluan asas bagi manusia. Penilaian tahap kandungan logam berat yang selamat dalam sampel air paip ini amat penting . Justeru, kajian ini di jalankan untuk mencapai beberapa objektif iaitu untuk mendapatkan tahap kandungan logam berat dalam sampel air paip bagi memastikan keselamatan penggunaan air paip tersebut sama ada selamat atau tidak berdasarkan parameter dan penyelarasan kualiti air untuk logam berat oleh MNDWQS dan US EPA, di samping itu menilai kandungan setiap elemen logam berat tersebut untuk menentukan yang mana paling banyak dan sebaliknya. Kajian ini juga ingin membandingkan tahap kandungan logam berat berdasarkan jenis tapak lokasi untuk mengambil sampel-sampel tersebut iaitu kawasan industri, pertanian dan perumahan. Dengan menggunakan AAS, hasil kajian menunjukkan bahawa logam berat ini memang terdapat dalam hampir keseluruhan sampel air tersebut. Kajian ini telah mencapai kesemua objektif yang ingin dicapai di mana kajian mendapati hampir semua kandungan logam berat melebihi tahap nilai kualiti air yang telah di gariskan. Kajian ini juga menunjukkan bahawa jenis lokasi untuk pengambilan sampel air ini mungkin mempengaruhi kadar kandungan logam berat dalam sampel air paip.

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CHAPTER 1

INTRODUCTION

1.1

Background and problem statement Water is the basic needs for living organisms in the world. People consume water daily to drink, bath, prepare food and others. Water sourced from rivers will be treated first before people can consume it via the tap water.

In water treatment process, there are few steps involve to ensure water cleanliness. The first step includes is flocculation process which combines small particles into larger particles. Then, the water will be filtered to remove all particles from it. After that, water undergoes ion exchange process to remove any inorganic contaminants. Then, adsorption of water in which to remove organic contaminants, unwanted coloring and taste-and-color causing compound take place. Lastly, chlorination process is carried out to disinfect the water.

Some people are not confident with the safety of consuming tap water. Although the water seems clean, they will not use tap water as the main source of drinking water. Instead they will buy filtered water or reverse osmosis water as the source of drinking water.

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Tap water might be contaminated with heavy metals. In the water treatment field, heavy metals refer to the heavy dense and metallic elements that could be found only at the trace levels in water. Nonetheless, these constituents are very toxic and tend to accumulate in the body in a long period of time.

Heavy metals such as Pb, Cd and mercury are micro-pollutants and of special interest as they have both health and environmental significance due to their persistence, high toxicity and bio-accumulation characteristics. The followings are some common heavy metals found in water:

i) Cu: Water turns blue-green in color as the corroded Cu inside of the pipes and mix together with the water as a precipitate. Cu in a very high quantity is toxic and may cause vomiting, diarrhea and loss of strength. In a long term, the toxicity can cause liver damage, kidney failure and ultimately death while the short term effect is gastrointestinal distress.

ii) Pb: Pb is very toxic and common heavy metals. It gets into the water from the corrosion of plumbing materials. Sources including paint, mining wasters, incinerator ash, automobile exhaust, water from Pb pipes and solder that are used to join Cu pipes, in fittings and faucets are made from brass. Intake of Pb causes delay in physical or mental development for infants and children. Whereby for adults, it may cause damage to kidneys, brain, and nervous system,

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learning and synthesizing protein, nerves, red blood cells ability, cancer, hypertension and hyperactivity.

iii) Cd: Origin includes electroplating, erosion of natural deposition, discharge from metal and plastic refineries, battery and paint waste, mining as well as sewage. It occurs mostly in association with zn and gets into the water from the corrosion of zn-coated galvanized pipes and fittings. It penetrated body via the food eaten and water drank. Cd can cause kidney disease and injures the renal, pulmonary, skeletal and testicular. In addition, is been recognized as a carcinogen. Renal failure tends to be the fatal due to the sensitive nature of the kidneys if there is a concentration of Cd.

iv) Hg: It is resulted from the leaching of soil due to acid rain, coal burning, residential and mining wastes, discharge from refineries, run off, land fills or croplands. Hg causes damage to the nervous system, kidneys and vision.

v) As: Enters the environment through herbicides, wood preservatives and mining industry. As may causes damage to skin, eyes, gastrointestinal tract , and liver. It may also cause cancer to the human being.

vi) Al: Exist through the leaching of acid deposition. The effect of Al to human body is it causes anemia and loss of bone strength and contribute to dementia and Alzheimer’s disease.

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There are basically five sources of heavy metals which contribute to the water pollution that are ores and metals, the use of metal compounds such as chromium salts in tanneries, Cu compound in agriculture and tetraethyl Pb as an anti-knock agent in gasoline, leaching of heavy metals from domestic wastes and solid waste dumps and heavy metals in human and animal excretions, particularly Zn.

Actually, the evaluation of heavy metals pollution in water is crucial. Although heavy metals are natural components in the environment, we have to consider them as the potentially toxic materials. Heavy metals concentration has increased in the air, soil and waters, especially in big cities and industrial areas. The main source of water is the tap water. We have to identify how clean the tap water from the heavy metals before we consume it.

Tap water conditioners are developing over recent years as technology has allowed new formulations to be created, with most improvements being led by the increasing challenges set by the variable quality of tap water over the years.

Adopted from the World Summit on Sustainable Development in 2002 that the target by 2015 is to reduce by half the proportion of people who are do not have access to safe sanitation facilities unable to reach, or to afford, safe drinking water.

An Environmental Working Group analysis of tap water test from 1998 through 2003 for more than 39000 communities nationwide shows that 260 pollutants were

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detected in the nation’s drinking water. The contaminants detected come from Agricultural pollutants, Sprawl, and Urban pollutants, Industrial pollutants, water treatment and distribution by products and others.

Health effects of contaminants found are cardiovascular of blood toxicity, cancer, developmental toxicity, endocrine toxicity, immunotoxicity, kidney toxicity, gastrointestinal

or

liver

toxicity,

musculoskeletal

toxicity,

neurotoxicity,

reproductive toxicity, respiratory toxicity and skin sensitivity.

In my study, I focuses on to determine the concentration of heavy metals in tap water and compared with safety level, besides the determination of most concentrated and least concentrated heavy metal in tap water and also comparing the concentration of tap water according to different location samples taken.

1.2

Significance of study The fact above shows that the presence of heavy metals in human body can affect health for a long period of time. It is important to know the concentration of heavy metals in tap metal because it is the main source of water that people consume everyday.

1.3

Objectives of study

1.3.1 The intention of this research is to determine the level of heavy metals in tap water in order to study the safety level of using tap water in Shah Alam.

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1.3.2 The specific objectives of the study are to:-

1.

Determine the concentration of Cu, Cd and Pb in tap water in order to identify the most concentrated heavy metal and the least concentrated heavy metal.

2.

Comparing the concentration of Cu, Cd and Pb in tap water samples from the location of industrial, agricultural and residential areas in Shah Alam , whether the type location influenced the concentration of heavy metals in tap water as well as the water safety level according to the parameters according to Malaysian National Drinking Water Quality Standard and also parameters of Maximum Concentration Level for drinking water supply by United State Environment Protection Agency.

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CHAPTER 2

LITERATURE REVIEW

2.1

Introduction The study of heavy metals contamination in water sample has been done by many researchers. It involves a few types of water like water from the river, sea, tap water, lake, dam and others. Most of the results have shown that heavy metals exist in these samples of water but the concentrations of their contamination are different and some of the results do not detect the existence of heavy metals in water samples.

2.2

The Study of Heavy Metals Mimoza Milovanovic, (2007) cited that the determination of pollution sources along the Axios / Vardar River in Europe showed that Cd, Cr, Zn, and Pb were present in the river sample.

The analysis has been done to determine Zn, Cd, Pb and Cu in marine water (Bruce, 2004). From the analysis, it can be concluded that toxic concentrations of trace metals interfere with the normal metabolic process of fish and other species of

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life in the marine environment and these metals can be passed into human who consume them and pose adverse effects on the human metabolic process.

Ohmichi et al. (2006) stated, the measurement of heavy metal levels in river near the Watarase River and in soil around them and also follow-up investigations on the condition of pollution in the Watarase River 1991 has been done. The result of this study concluded that the environment around the Watarase River has been steadily improved so that the safety in that environment is assured. So, the current status of the Ashio area provided better conditions than in the past.

The study about the determination total content of Cd, Cu, Pb, Fe, Ni and Co in tap water sample has been done by Farghaly (2003). The result of the study indicate that metal ion concentrations values in tap water at Assiut City was below the recent proposed criteria for water quality and below safety baseline levels of the World, European, American Chemical Standards and the Egyptian Chemical Standard of Ministry of Health. It could be concluded that no effect was observed on Cd concentration and a small effect was observed (approximation 15%) for Zn, Pb and Cu ion concentrations.

Szoke E. (2005) stated in his research on the heavy metal pollution of some cave waters of the Karsts of Aggtelek from 2000 until 2005 that the contents of metallic contents in the cave waters is higher than what is expected.

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Mustafa et al. (2006) cited on his study about the determination of trace amounts of Cr (III), Fe (III), Pb (II) and Mg (II) that the good result was obtained where relative standard deviations less than 10% and recoveries were more than 95%.

The study on the determination of organic pollutants and heavy metals in sediments and water samples associated with the petrochemical complex in La Plata district Argentina had been done (Labunska et la. 2000). The result has shown that the area was still contaminated with the petroleum products and several heavy metals like Cu, Pb, Hg and Zn had been detected in the sediment samples above the background levels.

The research about multi element determination of heavy metals in water samples by continuous powder introduction MIP AES after preconcentration on activated carbon had been done by Krzysztof et al ., (2004). From the study, it could be concluded that the analytical potential of the proposed CPI-MIP-AES method was higher owing to high enrichment factors available. The preconcentration of the metals studied on activated carbon Pb not only to high enrichment factors but also eliminates matrix interferences caused by alkali and alkaline earths elements present in the natural water samples.

Open-focused microwave-assisted extraction and ICP-OES determination of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn from surface sediments of the estuary of Bilbao (Basque Country, North of Spain) was carried out by Landajo et al. (2004). The

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result concluded that the two main patterns observed were a steady increment of the metal concentration along all the campaigns in the samples collected in the Galindo River and a seasonal variation in the Nerbioi-Ibaizabal River, with higher metallic content during summer time and lower content during winter time.

Zhou et al. (2007) stated that the determination concentration of Cu, Zn, Cd, and Pb in Dabaoshan Mine, Guangdong Province, China has been done. From the study, it showed that the present of Cu, Zn, Cd, and Pb can cause environment pollution.

The applicability of 2, 2-bipyridyl and erythrosine co-precipitation method for the separation and preconcentration of some heavy metals such as Cd, Co, Cu, Ni, Pb, and Zn in actual samples for their determination by ICP-OES and FAAS was studied by Barbara (2007). From the study, it could be concluded that introductory group concentration of the analytes allow for one order reduction of limit of detection of these metals using both techniques. Recovery percentages of the analytes amount are more than 90%. The results of determination of the analytes studied, after their prior concentration, which is obtained by ICP-OES technique are comparable with the ones obtained using FAAS technique. It is advisable to prepare standard solution for calibration curve in both techniques in the same way as the samples. It allows eliminating the effect of the reagent matrix.

Industrial chemicals in tap water involves the observation of EWG's analysis of water supplier's tap water test results which shows that water contaminated with

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166 industrial pollutants, including plasticizers, solvents, and propellants, are served to 210,528,000 people in 42 states. 56% of those people were served with water consist of one or more industrial contaminants present at levels above nonenforceable, health-based limits. 94 of the industrial chemicals detected in tap water are unregulated, without a legal, health-based limit in tap water.

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CHAPTER 3

METHODOLOGY

3.1

Background The study was implemented in Shah Alam which is the main city in Selangor with the width of 290.3 km from north to south. Shah Alam was chosen as the location of this study. Shah Alam consists of all three types of areas used for sampling that are industrial, residential and agricultural areas.

3.2

Site Sampling All of the samples were collected from 3 sites for each area.

For industrial areas: the tap water sample was taken from plants which use chemical to execute their process, such as fertilizer at Padang Jawa, synthetic organic at i-city and also production of drink container plants at Seksyen 7.

For residential areas: the tap water sample was taken from houses at Seksyen 7, Seksyen 4 and Seksyen 17 (terrace and flat house).

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For agricultural areas: the tap water sample was taken from Agricultural park at Seksyen 8 ( Bukit Cerakah ) and also the natural garden at Seksyen 4 ( Taman Perhutanan ).

Figure 3.2

Map of Shah Alam and Sampling Location

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3.3

Materials

3.3.1 Sample Samples were taken from 3 different areas which are industrial, agricultural and also residential area.

3.3.2 Chemicals a) Nitric Acid b) Tap water sample c) Standard solution of Cd, Pb and Cu

3.3.3 Apparatus a) 1L clean polyethylene bottles that had been washed with deionize water before sample collection b) Label of the bottle for identification c) Micropipette / pipette to prepare accurate concentration of standard solution d) Volumetric flask 100 ml e) Small beaker

3.3.4 Instrument a) Perkin Elmer Analyst 400 Flame Atomic Absorption Spectroscopy (FAAS)

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