I N S T I T U T I O N

ISSUE : 03/2014

A Hwa Chong Institution Research Publication

I N S T I T U T I O N

www.hci .edu.sg

ACKNOWLEDGEMENTSWe are deeply grateful to our principal, Dr. Hon Chiew Weng and deputy principals Mrs. Chin-Leow Bee Kuan and Mr. Chan Kwok Leong for their strong support in our students science research programmes. We would also like to give special thanks to our Dean of Research Studies, Mrs. Tan-Tiang Ai Chin, who has given us her strong support throughout the production.

The extent to which science research has been developed at Hwa Chong has been possible due to the support of our external research mentors and teacher mentors. They teach, guide and provide resources for our learning journeys.

We are also indebted to the schools laboratory staff for staying back in school late during crucial periods; offering their invaluable support and giving our students the extra time required to complete their research projects.Voyager, the brainchild of members from the Science Students Research Council, was established

in 2010. The theme varies from year to year and in this third issue of Voyager, we explore the theme Discover: Forging Ahead Together for the next Milestone. This publication aims to serve as a microcosm of the many facets of research and seeks to reveal the research experiences and extensive support network of Hwa Chong Institutions research community.

Editor-in-Chief

Chiang Yan Xin 14S7F

Publication Team

Chiang Yan Li 13S7BPoh Yong Rui 13S7JNg Jun Xuan 13S7GKwan Jing Ling 14S79Lee Zhi Rui 14S79Zhou Pei Yu 14S6A

Teacher Advisor

Dr Kelvin Tan Yong LengEducation Consultant/ Research

ABOUTVOYAGER

www.hci .edu.sg

ACKNOWLEDGEMENTSWe are deeply grateful to our principal, Dr. Hon Chiew Weng and deputy principals Mrs. Chin-Leow Bee Kuan and Mr. Chan Kwok Leong for their strong support in our students science research programmes. We would also like to give special thanks to our Dean of Research Studies, Mrs. Tan-Tiang Ai Chin, who has given us her strong support throughout the production.

The extent to which science research has been developed at Hwa Chong has been possible due to the support of our external research mentors and teacher mentors. They teach, guide and provide resources for our learning journeys.

We are also indebted to the schools laboratory staff for staying back in school late during crucial periods; offering their invaluable support and giving our students the extra time required to complete their research projects.Voyager, the brainchild of members from the Science Students Research Council, was established

in 2010. The theme varies from year to year and in this third issue of Voyager, we explore the theme Discover: Forging Ahead Together for the next Milestone. This publication aims to serve as a microcosm of the many facets of research and seeks to reveal the research experiences and extensive support network of Hwa Chong Institutions research community.

Editor-in-Chief

Chiang Yan Xin 14S7F

Publication Team

Chiang Yan Li 13S7BPoh Yong Rui 13S7JNg Jun Xuan 13S7GKwan Jing Ling 14S79Lee Zhi Rui 14S79Zhou Pei Yu 14S6A

Teacher Advisor

Dr Kelvin Tan Yong LengEducation Consultant/ Research

ABOUTVOYAGER

EDITORIALThe advent of 2014 marks new beginnings for Voyager. Featuring a plethora of research-centered articles, we remain committed to bringing to you the finest of Hwa Chongs research work.

We maintain a culture of continuous transformation. This year, Voyager has evolved to include Foundations for the Future, which feature articles with a personal and distinct focus on the research experiences of Hwa Chongs alumni who have embarked on their various endeavours after graduating from Hwa Chong. Our team has had the privilege of sharing their insights on their research experiences as well as the potent driving force behind their choices to embark on their present disciplines with you. We believe that by sharing both the experiences of our present students as well as our alumni, we can impart profound meaning to the relevance of Hwa Chongs research experience to the present and the future.

We hope that this issue of Voyager will be an invigorating and insightful read that serves as a harbinger of Hwa Chongs distinctive research culture and close-knitted research community. We also hope that future Voyager editorial committees will continue to present the best of our students work to you.

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Yours sincerely,Chiang Yan Xin

Editor-in-Chief

On behalf of the Voyager Editorial Committee 2014

06 FOREWORD07 SPOTLIGHT:Nurturing Bright Sparks

09 FOUNDATIONS FORTHE FUTURE14 STUDENTS VOICES

37 DETERMINING THE AMINO ACIDS INVOLVED IN INHIBITION OF PDE4B BY STRUCTURALLY-DIVERSE COMPOUNDS

51 INVESTIGATION INTO THE RELATIONSHIP BETWEEN VIOLIN STRING TIMBRE AND ITS HARMONIC STRUCTURE 57 HISTORIC VENUS TRANSIT 2012 AND INSTRUMENTATION

63 ACKNOWLEDGEMENTS

45 FALL DETECTION SYSTEM BASED ON KINECT SENSOR USING NOVEL DETECTION AND POSTURE RECOGNITION ALGORITHM

CONTENTS

24 QUORUM SENSING INHIBITION ACTIVITY OF SELECTED TRADITIONAL CHINESE MEDICINAL (TCM) HERBS TO INHIBIT BIOFILM FORMATION

32 GREEN SYNTHESIS OF SILVER NANOPARTICLES USING LALANG EXTRACT

17 USE OF RECYCLED CLAM SHELLS IN WATER PURIFICATION

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The different frequency of stained colonies for different buffers may be correlated to the rate and type of mutagenesis that the 6 buffers confer. High rates of mutagenesis may lead to changes in the essential amino acids of the catalytic domain, thus rendering the PDE product non-functional.

Cai AnniDetermining the amino acids involved in inhibition of PDE4B by structurally-diverse compounds

Our fall detection system is capable of processing incoming sensor information and displaying of results concurrently without a loss in processing speed or performance degradation.

Lee Choon KiatFall Detection System based on Kinect Sensor using Novel Detection and Posture Recognition Algorithm

Four versions of prototype were constructed using lala clam and blood cockle shells. With each version, improvement was made to enhance the feasibility of the prototype.

Ong Yinn Jaye, Yeo Kang Le and Gong Wei Jin Use of recycled clam shells in water purification

This research provides a method to build a database of different instrumental timbre. Findings in this studycan be used in computer generated music to create more variance in instrumental timbre.

Yang Liuyi and Wang Jia Investigation into the relationship between violin string timbre and its harmonic structure

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Now in its third issue, Voyager highlights some of our students exemplary research projects. It is heartening to see the next generation of scientific talents eager to contribute positively to the world around them.

Indeed, such passion has been the driving force behind humanitys efforts to overcome barriers and expand our boundaries. In todays complex and uncertain world, the challenges are multifaceted and immense. However, the faith scientists have in the transformative power of research remains strong. It is research that will enable us to not just survive, but thrive in the future.

This year, our students continue to work under the mentorship of esteemed research institutions and industry partners, such as the Agency for Science, Technology and Research (A*STAR), National University of Singapore (NUS), Nanyang Technological University (NTU), and Singapore University of Technology and Design (SUTD). Our partners demonstrate the extensive breadth and depth of cutting-edge research that Singapore has been lauded for. In addition, our own School Scientist Programme, started in 2012, has shown much promise. The school scientists have taken students under their wing, proffering their wealth of experience and knowledge. Under their mentors auspices, our students have been inspired to think creatively and critically, and to always direct research for the benefit of mankind. We are thus grateful for their dedication and guidance.

In this issue of Voyager, you will read about how our students have striven to help society and the world-at-large overcome critical obstacles. Under the mentorship of Dr Lee Vwen Yen, from the Institute for Infocomm Research, A*STAR, Lee Choon Kiat (12S68) invented a fall detection system for the elderly who live alone. The system can automatically recognise falls and notify healthcare services to provide timely assistance, a boon to the elderly in ageing societies all around the world. Ong Yinn Jaye (13S75), Yeo Kang Le (13S79) and Gong Wei Jin (13S67) meanwhile explored the use of clam shells to remove heavy metal ions from water, and constructed a low-cost water filter. Their project is a significant breakthrough that might significantly aid developing countries in their critical quest for clean water. These projects and the other equally impressive studies all have the potential to shape the worlds future in a revolutionary manner.

Learn from yesterday, live for today, hope for tomorrow. The important thing is to not stop questioning. Albert Einsteins quote encapsulates what we hope to develop our budding scientists into inquisitive scientific leaders who constantly seek to find new hopes for the future. After all, science will remain a constructive and guiding force only if its leaders are driven by two important values passion and compassion, the very values that we nurture in our students.

FOREWORD

Dr Hon Chiew WengPrincipalHwa Chong Institution

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07sciences under the mentorship of scientists from NUS and the Defence Science and Technology Agency (DSTA). Similarly, the Nanyang Research Program (NRP) helmed by Nanyang Technological University (NTU) provides a platform for our students to explore their research interests in engineering, natural sciences and social sciences. In addition, Hwa Chong has formed firm partnerships with local research institutes such as the Agency for Science, Technology and Research (A*STAR) as well as overseas universities such as University of Glasgow, Scotland. These strong alliances provide a vibrant hub for scientific discoveries and opinions where the passion and curiosity of Hwa Chong students are cultivated.

Hwa Chongs own internal research programme, the Centre for Talent Development in Science (CenTaD), aims to promote a strong culture and passion for research amongst its students.

Hwa Chong provides many platforms, such as the annual CenTaD Research Conference, for budding student researchers to communicate their research projects and receive valuable feedback from their peers as well as mentors. The Singapore Science Engineering Fair (SSEF) allows for outstanding student researchers to represent the school in showcasing their work on the national stage, presenting their projects to experts hailing from the

Research is to see what everyone has seen, and to think what nobody has thought. Nobel laureate Albert Szent Gyorgyi, alongside many great scientists, made groundbreaking discoveries in the most unsuspecting of circumstances. Hwa Chong too hopes to lay the foundations for such discoveries by developing our students critical, creative and caring minds, grooming them to become leaders in the scientific community of tomorrow.

Hwa Chongs own internal research programme, the Centre for Talent Development in Science (CenTaD), aims to promote a strong culture and passion for research amongst its students. Under the guidance of experienced mentors and laboratory staff, Hwa Chong students engage in authentic problem-solving and gain in-depth knowledge beyond the walls of the classroom. Equipped with specialised laboratories with the ability to support projects in the fields of environmental science, synthetic chemistry, biology and photonics, Hwa Chongs Science Research Center (SRC) is a dynamic nexus for the exchange of scientific ideas and a facility to promote innovation.

The Science Research Program (SRP), jointly organised by the Ministry of Education and the National University of Singapore (NUS), provides opportunities for students to delve into research fields as diverse as robotics and engineering, computer science, microbiology and pharmaceutical

Spotlight:NURTURING

BRIGHTSPARKS

academia, research institutes and industry. Moreover, Hwa Chong also hosts the annual International Science Youth Forum (ISYF), where our top science research students are joined by like-minded peers from across the globe. With activities ranging from master classes with Nobel Laureates and Fields Medallists, to understanding Singapores research landscape through visits, to dialogue sessions where ideas are exchanged and experiences shared, ISYF sets the stage for close interaction between these top science talents from all over the world, enabling them to forge valuable friendships and gain new insights into the global research culture.

Any research student will ascertain the fact that research is far from a bed of roses. It is rigorous and the demanding nature of research can be at times overwhelming, but the process of gaining new insights and perspectives make research an enjoyable and exhilarating experience. As Tricia Teo Wei Tian from 14S7D shared with us, Research is really about keeping an open mind. There is always a chance for experimental results to deviate from your expectations so you cannot maintain a fixed mindset. You have to be able to learn from each attempt, and be willing to consider and try different ways of approaching the same problem.

Ultimately, in research, the focus is not solely on the end-product, as the process is equally if not more

important. Students embark on rigorous learning journeys and they end up gaining more than just their research findings: they are empowered with the ability to think creatively, solve problems and persevere. They see problems in a new light, think out of the box and by applying the valuable skills that they have learnt, offer refreshing perspectives.

Students embark on rigorous learning journeys and they end up gaining more than just their research findings: they are empowered with the ability to think creatively, solve problems and persevere.

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Our alumnus, Mr Sng Jie Han Timothy (09S79) was part of a team of 3 HCI students who undertook a project under the Science Research Program, which was co-mentored by a faculty member from the Faculty of Dentistry as well as a marine biology expert from the Tropical Marine Science Institute. This project was awarded the Gold Award at the 2010 Singapore Science and Engineering Fair (SSEF), and the team was selected to represent Singapore at the 2010 International Science and Engineering Fair (ISEF). Timothy is currently an undergraduate at the Faculty of Dentistry at NUS.

Could you tell us more about your research project?

My research team was investigating the potential of barnacle cement in dentistry, more specifically as a form of dental material.

We understand that your initial research topic was

not directly related to the application of barnacles in

the dentistry sector. Your team came up with the

ingenious idea of applying what was previously

undesirable for the shipping industry to dentistry.

What was your teams inspiration for delving into

this cross-disciplinary research topic and how was

this idea developed?

All of us in the team had experiences with dental restorations (fillings) and orthodontic treatment where the dental material used plays a very crucial role in determining the longevity and success of the specific treatment.

What inspired us was a meeting with our project mentor, A/P Stephen Hsu. He mentioned how the harsh environment of our oral cavity is akin to the

ocean and yet barnacles can still stick so sturdily to rocks and surfaces of ships etc. Interestingly, one of our team mates was on orthodontic treatment and somehow we drew parallels between the barnacle and the orthodontic brackets (braces) that were adhered to his teeth.

From there, we were very intrigued and read up on the reason for such a phenomenon. This protein-based glue, commonly termed as barnacle cement, secreted by barnacles was found to be a bane to the shipping industry and many material scientists, one of whom was our co-mentor, Dr Gary H. Dickinson, were exploring ways to develop anti-fouling surfaces to weaken this robust adhesion between barnacles and ships.

With guidance from our 2 mentors (from different fields), we continued researching on how we may utilise this material for clinical dentistry,

Reflecting on your time as a student, what forms of

research exposure did you have and what forms of

support did you receive from the school?

In year 3 and 4 at High School, I was trained under the Science & Math Research Programme (SMRP). Via SMRP, students learnt about the basics of scientific research from guest scientists, teachers & our seniors. We then proceeded to conduct experimental projects, eventually presenting and defending our research paper in the presence of teacher assessors. I believe that the HCI Integrated programme has offered me much more liberty to participate actively in research projects and research-related activities such as the research collaboration cum exchange programme with the Academy of Science-Virginia, International Science Youth Forum (ISYF) and various science fairs. These opportunities to learn beyond the

FOUNDATIONSFOR THE FUTURE

The Voyager Editorial Team had the privilege of speaking to three of our distinguished alumni: Dr Vincent Tan Yan Fu (98S34), Dr Guo Huili (00S73) and Mr Sng Jie Han Timothy (09S79). Leveraging on the solid foundations built during their time in Hwa Chong, Dr Tan and Dr Guo, who are married to each other, continued to pursue their passion for research in their present careers while Mr Sng is currently a Dentistry undergraduate at the National University of Singapore. They share with us their research experiences and what influenced them to embark on their present fields and disciplines

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There were other fun-filled ISEF-organised events throughout that entire week at San Jose, including the pin-exchange, Nobel panel discussion as well as an exhibition of GOOGLEs technology (robotics and satellite technology).

What challenges did your team face during your

research and how did you overcome them?

This project has been a fruitful learning journey as I have not only acquired a deeper understanding of the multi-faceted aspects of dental research but have also grown in terms of character. The first bottleneck came when my group spent one month brainstorming for a research topic but remained undecided on any. Nevertheless, with the motivation of our mentors, my team persevered on and finally chanced upon a unique topic that we were all excited about. Despite having a slow start, the passion we had for our novel and well thought-out project was the very source of our motivation. Thus, while we often faced challenges in the experimental phase of our research, we were always determined to overcome them as a team.

Any words of encouragement or advice for your

juniors?

Take ownership of your project. Be proud of it.

Work on a topic that you are really very keen on and this passion will likely be your source of fuel in times of stress and fatigue as you face various challenges in your project.

If you are unexcited in your research, it is hard to expect others (be it your peers or judges) to be interested in it.

Thank you very much and we wish you the very best

in your future endeavours!

Timothy (right) with fellow Hwa Chong team members Joseph Ang (09S7A) and Clement Lee (09S6K) at the Intel ISEF 2010.

designated O level science syllabus has seeded in me the academic curiosity and drive to apply knowledge in experimental research.

In addition, the helpful and patient laboratory staff at Hwa Chongs Science Research Centre, especially the laboratory manager, Madam Lim Cheng Fui, have always been pillars of support from the time I was doing experimental research in year 3 till my final year in college. I am very grateful for their guidance and they are certainly assets to HCI.

We understand that your team emerged as gold

medallists in the Singapore Science and Engineering

Fair (SSEF) and represented Singapore in the

International Science and Engineering Fair (ISEF).

When you first started your research, were you

expecting such an outcome?

Personally, I was hoping that our research was, as much as possible, conducted to a certain degree of completion (that we agreed upon before we started on our experiments). Receiving awards in such science fairs are often stated to be a bonus or icing on the cake. Still, I felt that they serve as a form of recognition and approval of the standards of ones research project. I was certainly exhilarated when we were given this opportunity to participate in ISEF. I would say that it is indeed by Gods grace!

Could you share with us more about your

experiences at ISEF?

The public viewing day was certainly memorable. As ISEF finalists, we had the chance to explain our work to the general public and even to one another. The depth and scope of the projects at ISEF were incredible and it was an eye opener to witness how peers of our age can actually come up with such detailed methodologies and creative ideas to tackle scientific problems.

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FOUNDATIONSFOR THE FUTURE

Dr Guo HuiliA recipient of National Science Scholarships from the Agency for Science, Technology and Research (A*STAR), Dr Guo (00S73) graduated from the University of Cambridge in 2005 with a B.A. degree in Natural Sciences. In 2011, she received her Ph.D. degree in Biology from the Massachusetts Institute of Technology (MIT). Dr Guo was awarded an Institute of Molecular and Cell Biology Independent Fellowship in 2012. She is currently an Adjunct Assistant Professor with the Department of Biological Sciences at the National University of Singapore (NUS), as well as the Lee Kong Chian School of Medicine at Nanyang Technological University. Dr Guo was recently selected to be one of the ambassadors for the UN Women STEM (Science, Technology, Engineering and Mathematics) program.

Dr Vincent Tan Yan FuDr Vincent Tan (98S34) graduated from the University of Cambridge with an undergraduate degree in Electrical Engineering as well as a Ph.D. degree in Electrical Engineering and Computer Science from MIT. He was a recipient of the Public Service Commission and A*STAR scholarships. After working at the Institute for Infocomm Research at A*STAR, Dr Tan joined NUS as an Assistant Professor, where he currently holds a joint appointment at both the departments of Electrical and Computer Engineering as well as Mathematics.

Dr Vincent Tan

Dr Guo Huili

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Dr Guo and Dr Tan, please tell us more about your

current research field and direction.

Dr Guo (HG): I use molecular biology and genomics to study how protein synthesis regulates cellular differentiation. This may sound abstract but is actually not: people are familiar with the idea that genes get turned on and off to make different types of cells; I am doing essentially that, just that I am focusing on a downstream step When a gene is turned on, messenger molecule known as the messenger RNA gets made, but this does not necessarily lead to the synthesis of a protein. I am studying how this step is regulated, and how it in turns controls the differentiation of different cell types. This is important because proteins are the foot soldiers that carry out most of the work in our cells. Because these pathways are so basic to a cell, deciphering how they work will impact upon many different biological processes and human diseases. Gaining insight into these mechanisms, and the potential to come up with novel therapeutic avenues, is what drives my interest in life science research.

Dr Tan (VT): My research is in the area of information theory. Just as biology is the science behind modern medicine, information theory is the science behind communication systems. It forms the mathematical basis of why your mobile phones work and why we can compress large files using g-zip efficiently. I establish the fundamental performance limits of transmitting information through noisy environments. Much of my work is mathematical in nature and involves using theories from and develop new theories in mathematical statistics and optimization. You can learn much more about my work from my homepage. www.ece.nus.edu.sg/stfpage/vtan/

What motivated you to embark on research as a

career?

HG: I have always liked to find out the reason behind phenomena and explain how things work. When the library couldnt answer all the why questions that I had, I decided that I would go into science to have a shot at finding things out myself. Growing up, I had pretty severe eczema, and wanting to know the reason behind my condition was also why I decided to go into the life sciences.

VT: I was motivated to embark on research due to my inspirational teachers in school and professors in Cambridge where I did my undergraduate studies. In particular, in the latter part of my studies in Cambridge, I knew I wanted to be a professor, to

combine my love for teaching and mentoring with the discovery of new ideas and theorems.

Could you kindly share with us some insights from

your research experience?

HG: I learnt from my professor at MIT to never ignore the small details/blips/weird result that come out of an experiment you never know when that blip could be telling you something important that has yet to be discovered. Do not be afraid of trying out new fields/testing out new ideas; you never know when you might find your passion/discover something because you bothered testing out your ideas (lots of people dont they just say, but dont do. And thats a mistake.)

VT: The main lesson I learned from my professor is to think hard rather than do too much. I remembered a meeting with him early on my PhD. I told him that I did A, B and C over the past week. He said great but added that the important thing in research is to think deeply rather than be too mired in the details of doing, which I guess is very Singaporean. I would advise interested Hwa Chong students to be involved in research as soon as possible so that you know whether this is the right thing for you. To be a successful researcher or academic, you need a certain type of personality. You need to be really driven and have initiative. You cant wait for things to happen.

What do you find most enjoyable in doing research

and what do you find most challenging?

HG: Most enjoyable: When you logically plan out an experiment after a lot of troubleshooting, deduce what you expect to see, and then see the fruits of your labour (i.e. the results are not uninterpretable uninterpretable results are worse than negative results), that is extremely rewarding. The nature of research is such that 99% of the time, you are disappointed by what you see, but in that 1% of the time when things work out, the joy is so addictive that you keep going back for more . Most challenging: In life science experiments, you often need to do quite a bit of optimisation and troubleshooting. Knowing when to keep going, and when to let go and try a new approach is not easy, and is still something Im learning to do now.

VT: The most enjoyable aspect of my job is the discovery of a new result and the proof of a difficult theorem. The realization that youre the first to demonstrate a non-trivial result is immensely satisfying. It means youre contributed to mankinds

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knowledge. Future references to your result would bear your name. Isnt that cool?The most challenging aspect is the knowledge that when you try to prove something difficult, you know that generations of brilliant people have tried and probably failed so it is hard to imagine that you can do it. I try not to be affected by this too much and to persevere or in some cases, work on a completely new and relatively unexplored area to break new ground.

In your opinion, what are some qualities that a

researcher should embody?

HG: (i) perseverance, (ii) working smart, (iii) always thinking of new angles to attack a problem, (iv) being aware of what is going on in your field, so that you can do point (iii).

VT: A certain naivety is sometimes crucial and can prove the difference between success and failure. If you dont know too much about a certain field, youre able to bring in tools and techniques from some other field youre more familiar in to solve problems. Of course, having a strong background in mathematics in my case is imperative.

Any words of advice for your Hwa Chong juniors

intending to pursue a career in research?

HG: Have more confidence in your abilities. One thing that was immediately apparent doing a PhD in the US is that Americans are very confident. Conversely, Singaporeans tend to be more reserved and afraid of voicing out, and in so doing, often shortchange ourselves.

VT: The training required to be a researcher is a very long journey. It is important to continually discover your interests along the way and not to be afraid of learning new things but if you do choose to do research, it is important to know the fundamentals well.

Thank you very much and we wish the both of you

all the best for your careers and family life!

STUDENTS VOICESResearch is formalized curiosity. It is poking and prying with a purpose

- Zora Neale Hurston

Every year, more than a hundred Hwa Chong Students embark on a new journey to satisfy their curiosity through the various research programmes such as CenTaD, NRP and SRP. These programmes provide students with the valuable opportunity to discover the unknown and embark on an unforgettable learning journey in the realm of research.

As the saying goes, If you want to build a ship, dont drum up people to collect wood and dont assign them tasks and work, but rather teach them to long for the endless immensity of the sea. Through their respective research projects, students enrich their learning experiences and enhance their understanding of their chosen area of study, going beyond the boundary of textbooks and school curriculum. In the process, students mature into innovative, independent and resilient individuals with acute and analytical minds.

Each students research experience is unique and each of them has a different story to tell. The following are but some of the responses we have collected from students who have taken their first exploratory steps into the invigorating realm of research.

What have you learnt from your research experience?You need to be very patient when conducting the experiments, and have to be very persistent and not give up. You will also need to think out of the box, because research is not methodological or straightforward. It is more than just carrying out processes and redoing things. You can use the methods others have used before and modify them to formulate a better method or simply improve on those methods.

In your opinion, what is the most enjoyable part of research?The most enjoyable part of research is to be able to learn from your mentor and peers, as well as interacting with them. When you face problems in your experiment, they will come to encourage you and similarly, when they face problems, you are able to help them. This is what makes research enjoyable. It is also exciting when you learn new and interesting things or when your mentor shows you how to handle or solve problems in a different way. It can really show you the practicality of science outside of textbooks and the rest of your academic subjects.

Rachel Ng Li En 12S70

What is an important quality you think research students should possess?I think that the one important quality research students should possess is passion. Only if they are passionate will they be dedicated, putting in effort constantly, and seeing the project through to completion, and this will build up to some discovery, be it small or large. This discovery may not have a significant impact on the world as we know it, but if they pursue their passion in the future, this initial research experience will definitely be beneficial, and they will continue to push the boundaries of science. Some might see spending countless hours in a lab as dry and dull, but for those who have a passion for research, they see meaning in what they do.

In what ways have Hwa Chong supported you?I would like to thank Hwa Chong for its amazing teachers, as without my mentor's help, my research team would not have had the opportunities we have had, and grown so much as researchers and as people. The laboratory staff would also tirelessly help all the research groups refine our laboratory techniques. Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

Tan Jiefeng 14S7B

Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

What inspired you to take up research?My research project involved the study of the metabolic pathways of FAT10, a ubiquitin-like protein which was found by the National Cancer Centre Laboratories to be involved in the disruption of cellular checkpoints of cell division. This was a topic that extended what I learnt as a biology student in class about cancer, and therefore brought real-life implications and applications of cancer studies into my experiences. Through the course of the project I was inspired by how the seemingly mundane tasks of transferring extremely small amounts of substances with a micropipette was vital in obtaining accurate results leading to the contribution to potentially groundbreaking fields for my mentors and other researchers. The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

Chiang Yan Li 13S7B

Research not only broadens our knowledge in science and bolsters our confidence in this subject; it trains our resilience as well. I did a research project at the Weizmann Institute in Israel as part of the International Summer Science Institute Programme. I met instrumental, empirical, and theoretical challenges at almost every step of the journey. Words of encouragement by my mentor kept me going and provided me with the courage to present my project in front of my peers. I hope that my newfound spirit of resilience will act as the vital scaffold for my eventual success. I believe that scientific research is just like the inexplicable black-holeit is mysterious, elusive, and we never know what we will pick up and learn from it. But one thing is for certain: it is certainly attractive!

Yi Kui Shuai 14S7B

The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

What has your research experience in Hwa Chong Institution taught you?Being in Hwa Chong has allowed me to be exposed to a plethora of research opportunities. I was very fortunate that Hwa Chong was able to provide me with the environment as well as the guidance. Throughre search, I have been able to acquire a whole range of skills. Last year, I had the privilege of presenting my project at the annual Singapore Science and Engineering Fair. I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well? Furthermore, the process allowed me to crystallize many of my ideas and the comments from the experts were invaluable. They provided me with many extensions and intriguing perspectives for me to further my research. I realised that research was indeed appealing to me. I felt reinvigorated every time I entered the laboratory. Research has become a passion. This year, I decided take up a project with the Institute of Materials Research and Engineering. Together with the guidance from my mentors and support from the school, I believe that I am able to continue doing what I love.

Han Kai Zhong Terence 14S7F

Why do you enjoy research?One of my favourite aspects of research is finding relationships and unlocking new possibilities. Something that seems as predictable as the path of a shuttlecock in badminton can hold hidden complexities that can be exploited. Simple factors such as speed and the terminal velocity of a shuttlecock can dramatically change the shape of its trajectory and these can be exploited by athletes and shuttlecock manufacturers in their designs.

Research is also about adapting to unforeseen circumstances. We faced many difficulties in conducting our experiments due to unfavourable environmental circumstances such as poor lighting and bad weather, and had to continuously adapt to these situations. These variables often affected our sensitive measurements and caused erratic results that required us to redo our experiments many times. Finding solutions to these problems and minimizing inaccuracies is a key part of research and is one of the most valuable skills I have learnt throughout my research journey.

Ho Kai Lun 14S6G

I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well?

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The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

What has your research experience in Hwa Chong Institution taught you?Being in Hwa Chong has allowed me to be exposed to a plethora of research opportunities. I was very fortunate that Hwa Chong was able to provide me with the environment as well as the guidance. Throughre search, I have been able to acquire a whole range of skills. Last year, I had the privilege of presenting my project at the annual Singapore Science and Engineering Fair. I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well? Furthermore, the process allowed me to crystallize many of my ideas and the comments from the experts were invaluable. They provided me with many extensions and intriguing perspectives for me to further my research. I realised that research was indeed appealing to me. I felt reinvigorated every time I entered the laboratory. Research has become a passion. This year, I decided take up a project with the Institute of Materials Research and Engineering. Together with the guidance from my mentors and support from the school, I believe that I am able to continue doing what I love.

Han Kai Zhong Terence 14S7F

Why do you enjoy research?One of my favourite aspects of research is finding relationships and unlocking new possibilities. Something that seems as predictable as the path of a shuttlecock in badminton can hold hidden complexities that can be exploited. Simple factors such as speed and the terminal velocity of a shuttlecock can dramatically change the shape of its trajectory and these can be exploited by athletes and shuttlecock manufacturers in their designs.

Research is also about adapting to unforeseen circumstances. We faced many difficulties in conducting our experiments due to unfavourable environmental circumstances such as poor lighting and bad weather, and had to continuously adapt to these situations. These variables often affected our sensitive measurements and caused erratic results that required us to redo our experiments many times. Finding solutions to these problems and minimizing inaccuracies is a key part of research and is one of the most valuable skills I have learnt throughout my research journey.

Ho Kai Lun 14S6G

I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well?

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USE OF RECYCLED CLAMSHELLS IN WATER PURIFICATION

Ong Yinn Jaye 13S75

Yeo Kang Le 13S79

Gong Wei Jin 13S67

Hwa Chong Institution

Research MentorMrs Sow-Peh Yoke Keow

Hwa Chong Institution

First prize in Singapore Junior Water Prize Competition 2013

Represented Singapore at the Stockholm Junior Water Prize Competition 2013, Sweden

INTRODUCTION

Access to clean water is a universal human right. Unfortunately, around 1.1 billion people globally do not have access to improved water supply sources whereas 2.4 billion people do not have access to any type of improved sanitation facility (WHO-UNICEF, 2000). The most affected are the populations in developing countries, living in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants. The people from these countries have to travel great distances to collect water every day, from water sources that are often polluted. The time spent on the collection of water could have been spent on more productive work for them to earn a living. According to the United Nations Development Programme (2006), 443 million school days are lost each year due to water-related diseases. Falling ill due to water related diseases also further reduces peoples ability to do work and completing education. According to WHO-UNICEF (2000), about 2 million people die every year due to diarrhoeal diseases and most of them are children less than 5 years of age. 88% of the diarrhoeal diseases are due to a lack of access to sanitation facilities, together with inadequate availability of water for hygiene and unsafe drinking water. Globally, the problem is deteriorating as cities and populations grow, and the need for water increase in agriculture, industry and households.

Water is critical to food production. While the majority of agriculture is rain-fed, irrigated agriculture provides some 40 per cent of the worlds food and consumes 75 per cent of worlds freshwater resources (The Gender and Water Development Report, 2003). Supplies of freshwater are increasingly threatened by population growth, changing lifestyles (use of more water per capita) and pollution. A lack of water has driven up the use of wastewater for agricultural production in poor urban and rural communities. More than 10% of people worldwide consume foods irrigated by wastewater that can contain chemicals or disease-causing organisms. Also, current rapid industrialization in developing countries has caused levels of heavy metals and pollutants to significantly increase in the last couple of decades, especially those from aquatic ecosystems. For example, according to an investigation conducted by the State Environmental Protection Administration, much of the Pearl River Delta in China has been polluted by heavy metals and that 40 per cent of farms and vegetable plots in the region had been polluted by these heavy metals (Wade, 2011).

Heavy metals pose a threat to the environment as they cannot be degraded and would remain in the soil and water for a long period of time. They produce their toxicity by forming complexes with proteins, in

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What have you learnt from your research experience?You need to be very patient when conducting the experiments, and have to be very persistent and not give up. You will also need to think out of the box, because research is not methodological or straightforward. It is more than just carrying out processes and redoing things. You can use the methods others have used before and modify them to formulate a better method or simply improve on those methods.

In your opinion, what is the most enjoyable part of research?The most enjoyable part of research is to be able to learn from your mentor and peers, as well as interacting with them. When you face problems in your experiment, they will come to encourage you and similarly, when they face problems, you are able to help them. This is what makes research enjoyable. It is also exciting when you learn new and interesting things or when your mentor shows you how to handle or solve problems in a different way. It can really show you the practicality of science outside of textbooks and the rest of your academic subjects.

Rachel Ng Li En 12S70

What is an important quality you think research students should possess?I think that the one important quality research students should possess is passion. Only if they are passionate will they be dedicated, putting in effort constantly, and seeing the project through to completion, and this will build up to some discovery, be it small or large. This discovery may not have a significant impact on the world as we know it, but if they pursue their passion in the future, this initial research experience will definitely be beneficial, and they will continue to push the boundaries of science. Some might see spending countless hours in a lab as dry and dull, but for those who have a passion for research, they see meaning in what they do.

In what ways have Hwa Chong supported you?I would like to thank Hwa Chong for its amazing teachers, as without my mentor's help, my research team would not have had the opportunities we have had, and grown so much as researchers and as people. The laboratory staff would also tirelessly help all the research groups refine our laboratory techniques. Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

Tan Jiefeng 14S7B

Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

What inspired you to take up research?My research project involved the study of the metabolic pathways of FAT10, a ubiquitin-like protein which was found by the National Cancer Centre Laboratories to be involved in the disruption of cellular checkpoints of cell division. This was a topic that extended what I learnt as a biology student in class about cancer, and therefore brought real-life implications and applications of cancer studies into my experiences. Through the course of the project I was inspired by how the seemingly mundane tasks of transferring extremely small amounts of substances with a micropipette was vital in obtaining accurate results leading to the contribution to potentially groundbreaking fields for my mentors and other researchers. The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

Chiang Yan Li 13S7B

Research not only broadens our knowledge in science and bolsters our confidence in this subject; it trains our resilience as well. I did a research project at the Weizmann Institute in Israel as part of the International Summer Science Institute Programme. I met instrumental, empirical, and theoretical challenges at almost every step of the journey. Words of encouragement by my mentor kept me going and provided me with the courage to present my project in front of my peers. I hope that my newfound spirit of resilience will act as the vital scaffold for my eventual success. I believe that scientific research is just like the inexplicable black-holeit is mysterious, elusive, and we never know what we will pick up and learn from it. But one thing is for certain: it is certainly attractive!

Yi Kui Shuai 14S7B

The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

What has your research experience in Hwa Chong Institution taught you?Being in Hwa Chong has allowed me to be exposed to a plethora of research opportunities. I was very fortunate that Hwa Chong was able to provide me with the environment as well as the guidance. Throughre search, I have been able to acquire a whole range of skills. Last year, I had the privilege of presenting my project at the annual Singapore Science and Engineering Fair. I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well? Furthermore, the process allowed me to crystallize many of my ideas and the comments from the experts were invaluable. They provided me with many extensions and intriguing perspectives for me to further my research. I realised that research was indeed appealing to me. I felt reinvigorated every time I entered the laboratory. Research has become a passion. This year, I decided take up a project with the Institute of Materials Research and Engineering. Together with the guidance from my mentors and support from the school, I believe that I am able to continue doing what I love.

Han Kai Zhong Terence 14S7F

Why do you enjoy research?One of my favourite aspects of research is finding relationships and unlocking new possibilities. Something that seems as predictable as the path of a shuttlecock in badminton can hold hidden complexities that can be exploited. Simple factors such as speed and the terminal velocity of a shuttlecock can dramatically change the shape of its trajectory and these can be exploited by athletes and shuttlecock manufacturers in their designs.

Research is also about adapting to unforeseen circumstances. We faced many difficulties in conducting our experiments due to unfavourable environmental circumstances such as poor lighting and bad weather, and had to continuously adapt to these situations. These variables often affected our sensitive measurements and caused erratic results that required us to redo our experiments many times. Finding solutions to these problems and minimizing inaccuracies is a key part of research and is one of the most valuable skills I have learnt throughout my research journey.

Ho Kai Lun 14S6G

I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well?

INTRODUCTION

Access to clean water is a universal human right. Unfortunately, around 1.1 billion people globally do not have access to improved water supply sources whereas 2.4 billion people do not have access to any type of improved sanitation facility (WHO-UNICEF, 2000). The most affected are the populations in developing countries, living in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants. The people from these countries have to travel great distances to collect water every day, from water sources that are often polluted. The time spent on the collection of water could have been spent on more productive work for them to earn a living. According to the United Nations Development Programme (2006), 443 million school days are lost each year due to water-related diseases. Falling ill due to water related diseases also further reduces peoples ability to do work and completing education. According to WHO-UNICEF (2000), about 2 million people die every year due to diarrhoeal diseases and most of them are children less than 5 years of age. 88% of the diarrhoeal diseases are due to a lack of access to sanitation facilities, together with inadequate availability of water for hygiene and unsafe drinking water. Globally, the problem is deteriorating as cities and populations grow, and the need for water increase in agriculture, industry and households.

Water is critical to food production. While the majority of agriculture is rain-fed, irrigated agriculture provides some 40 per cent of the worlds food and consumes 75 per cent of worlds freshwater resources (The Gender and Water Development Report, 2003). Supplies of freshwater are increasingly threatened by population growth, changing lifestyles (use of more water per capita) and pollution. A lack of water has driven up the use of wastewater for agricultural production in poor urban and rural communities. More than 10% of people worldwide consume foods irrigated by wastewater that can contain chemicals or disease-causing organisms. Also, current rapid industrialization in developing countries has caused levels of heavy metals and pollutants to significantly increase in the last couple of decades, especially those from aquatic ecosystems. For example, according to an investigation conducted by the State Environmental Protection Administration, much of the Pearl River Delta in China has been polluted by heavy metals and that 40 per cent of farms and vegetable plots in the region had been polluted by these heavy metals (Wade, 2011).

Heavy metals pose a threat to the environment as they cannot be degraded and would remain in the soil and water for a long period of time. They produce their toxicity by forming complexes with proteins, in

which carboxylic (-COOH), amine (-NH2), and thiol (-SH) groups are involved. These modified biological molecules lose their ability to function properly and result in the malfunction or death of the cells. When metals bind to these groups, they inactivate important enzyme systems or affect protein structure, which is linked to the catalytic properties of enzymes (Adepoju-Bello and Alabi, 2005).

Many industries such as mining, electroplating and piping discharge waste which contains high levels of metal ions. For example, copper is widely present in metal-bearing industrial discharges, and if not treated can cause damage to a variety of aquatic fauna such as fish and invertebrates (Ng et al, 2002).

The presence of metal ions in domestic drinking water is also a problem in many countries. Lead accumulation causes major health problems such as immune disorders and lead-induced intelligence impairment, while iron contamination results in poor tasting and unattractive water with a distinctive reddish-brown colour (World Health Organisation, 1996). In fact, there was a case in 2009 where residents in Singapore had reported seeing iron contaminated reddish-brown coloured water coming out from taps (Kreamer, 2009). Thus, it can be seen that contamination of drinking water by corroded pipes can indeed be a cumbersome problem.

Various kinds of methods have been developed to purify contaminated water around the world, such as the invention of desalination plants and sedimentation (Lalov et al., 2000). However, such methods are not cost effective. Developing countries cannot afford expensive filtration systems to treat wastewater it is difficult for them (and other developing countries) to obtain pure drinking water.

Hence, scientists have explored alternatives which are more cost effective. One popular alternative is the biosorption of metal ions by metabolically inactive non-living biomass of microbial or plant origin. Due to their unique chemical composition, metabolically inactive dead biomass sequesters metal ions, by forming metal complexes from a solution and removing the necessity to maintain special growthsupporting conditions (Ahluwalia and Goyal, 2006).

Another group of researchers found that shells of crustaceans such as crabs and shrimp can be used to remove heavy metals. This is mainly because their shells are made up of the material chitin which has the ability to adsorb toxic metals (Karthikeyan et al., 2005). Seashells have also been tested for their ability to remove zinc, lead, cadmium and iron (Reilly, 2009). Researchers found that flooding ground shells with highly contaminated water would cause the metals to be removed by the shell. Shells consist of aragonite, a mineral that is found to swap its calcium ions in exchange for heavy metal ions. The metals trapped are in a solid state and are harmless towards the environment.

This study explores the feasibility of constructing a filter from low cost and easily available material which can be used to remove heavy metal ions. The ability of three types of clam shell (mussel, lala clam and blood cockles) in removing copper(II), iron(III) and lead(II) ion was investigated and the most effective shell was used to construct the prototype. If successful, such a filter can be used in developing countries to help alleviate the problem of access to clean water caused by heavy metal pollution.

HYPOTHESES

1) All three types of shells are able to remove metal ions.2) The prototype constructed using clam shell is effec-tive in removing metal ions from contaminated water.

MATERIALS AND METHODS

MaterialsShells of lala clam, blood cockles and mussels were collected. The shells were washed with deionised water and dried in an oven at 70C for 24 hours. The solutions containing various concentrations of copper(II) ion, lead(II) ion and iron(III) ion were prepared from copper(II) sulfate, lead(II) nitrate and iron(III) nitrate respectively.

Preliminary studies:

1) To investigate effectiveness of removing metal ions with shells:0.5g of each type of shell was added to 50ml of 50ppm metal ion solution. The mixture was stirred on a magnetic stirrer for 60 min, after which it was filtered. The filtrate was analysed for the concentration of metal ion remaining using a AA spectrophotometer (AA 6300 Shimadzu) for lead (II) and a colorimeter (HACH, DR/890) for copper (II) and iron(III) ion. A control containing same volume of metal ion solution but without shell was subjected to the same experimental conditions.

2) Effect of pH on removal of metal ionsThe pH of metal ion solution was adjusted to 2 or 5 using Nitric acid (HNO3) or Sodium hydroxide (NaOH). pH above 5 was not studied as the metal ions were observed to precipitate out as metal hydroxide at pH greater than 5.

50ml of the solution with the desired pH was stirred with 0.5g of shell for 60min. After 60 min, the mixture was filtered and the metal ion remaining in the filtrate determined.

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What have you learnt from your research experience?You need to be very patient when conducting the experiments, and have to be very persistent and not give up. You will also need to think out of the box, because research is not methodological or straightforward. It is more than just carrying out processes and redoing things. You can use the methods others have used before and modify them to formulate a better method or simply improve on those methods.

In your opinion, what is the most enjoyable part of research?The most enjoyable part of research is to be able to learn from your mentor and peers, as well as interacting with them. When you face problems in your experiment, they will come to encourage you and similarly, when they face problems, you are able to help them. This is what makes research enjoyable. It is also exciting when you learn new and interesting things or when your mentor shows you how to handle or solve problems in a different way. It can really show you the practicality of science outside of textbooks and the rest of your academic subjects.

Rachel Ng Li En 12S70

What is an important quality you think research students should possess?I think that the one important quality research students should possess is passion. Only if they are passionate will they be dedicated, putting in effort constantly, and seeing the project through to completion, and this will build up to some discovery, be it small or large. This discovery may not have a significant impact on the world as we know it, but if they pursue their passion in the future, this initial research experience will definitely be beneficial, and they will continue to push the boundaries of science. Some might see spending countless hours in a lab as dry and dull, but for those who have a passion for research, they see meaning in what they do.

In what ways have Hwa Chong supported you?I would like to thank Hwa Chong for its amazing teachers, as without my mentor's help, my research team would not have had the opportunities we have had, and grown so much as researchers and as people. The laboratory staff would also tirelessly help all the research groups refine our laboratory techniques. Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

Tan Jiefeng 14S7B

Hwa Chong has invested intelligently into grooming young student researchers, by having a well-equipped Science Research Centre, and by providing us with the opportunities for participating in science fairs and international competitions. Hwa Chong is the wind beneath our wings.

What inspired you to take up research?My research project involved the study of the metabolic pathways of FAT10, a ubiquitin-like protein which was found by the National Cancer Centre Laboratories to be involved in the disruption of cellular checkpoints of cell division. This was a topic that extended what I learnt as a biology student in class about cancer, and therefore brought real-life implications and applications of cancer studies into my experiences. Through the course of the project I was inspired by how the seemingly mundane tasks of transferring extremely small amounts of substances with a micropipette was vital in obtaining accurate results leading to the contribution to potentially groundbreaking fields for my mentors and other researchers. The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

Chiang Yan Li 13S7B

Research not only broadens our knowledge in science and bolsters our confidence in this subject; it trains our resilience as well. I did a research project at the Weizmann Institute in Israel as part of the International Summer Science Institute Programme. I met instrumental, empirical, and theoretical challenges at almost every step of the journey. Words of encouragement by my mentor kept me going and provided me with the courage to present my project in front of my peers. I hope that my newfound spirit of resilience will act as the vital scaffold for my eventual success. I believe that scientific research is just like the inexplicable black-holeit is mysterious, elusive, and we never know what we will pick up and learn from it. But one thing is for certain: it is certainly attractive!

Yi Kui Shuai 14S7B

The process of the scientific method is a meticulous and noble oneit seems almost too easy to overlook the fact that mundane processes contribute significantly to humanity.

What has your research experience in Hwa Chong Institution taught you?Being in Hwa Chong has allowed me to be exposed to a plethora of research opportunities. I was very fortunate that Hwa Chong was able to provide me with the environment as well as the guidance. Throughre search, I have been able to acquire a whole range of skills. Last year, I had the privilege of presenting my project at the annual Singapore Science and Engineering Fair. I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well? Furthermore, the process allowed me to crystallize many of my ideas and the comments from the experts were invaluable. They provided me with many extensions and intriguing perspectives for me to further my research. I realised that research was indeed appealing to me. I felt reinvigorated every time I entered the laboratory. Research has become a passion. This year, I decided take up a project with the Institute of Materials Research and Engineering. Together with the guidance from my mentors and support from the school, I believe that I am able to continue doing what I love.

Han Kai Zhong Terence 14S7F

Why do you enjoy research?One of my favourite aspects of research is finding relationships and unlocking new possibilities. Something that seems as predictable as the path of a shuttlecock in badminton can hold hidden complexities that can be exploited. Simple factors such as speed and the terminal velocity of a shuttlecock can dramatically change the shape of its trajectory and these can be exploited by athletes and shuttlecock manufacturers in their designs.

Research is also about adapting to unforeseen circumstances. We faced many difficulties in conducting our experiments due to unfavourable environmental circumstances such as poor lighting and bad weather, and had to continuously adapt to these situations. These variables often affected our sensitive measurements and caused erratic results that required us to redo our experiments many times. Finding solutions to these problems and minimizing inaccuracies is a key part of research and is one of the most valuable skills I have learnt throughout my research journey.

Ho Kai Lun 14S6G

I had to learn to present my research in the most succinct manner to my fellow peers as well as the general public. After all, what is science if we cant communicate it well?

INTRODUCTION

Access to clean water is a universal human right. Unfortunately, around 1.1 billion people globally do not have access to improved water supply sources whereas 2.4 billion people do not have access to any type of improved sanitation facility (WHO-UNICEF, 2000). The most affected are the populations in developing countries, living in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants. The people from these countries have to travel great distances to collect water every day, from water sources that are often polluted. The time spent on the collection of water could have been spent on more productive work for them to earn a living. According to the United Nations Development Programme (2006), 443 million school days are lost each year due to water-related diseases. Falling ill due to water related diseases also further reduces peoples ability to do work and completing education. According to WHO-UNICEF (2000), about 2 million people die every year due to diarrhoeal diseases and most of them are children less than 5 years of age. 88% of the diarrhoeal diseases are due to a lack of access to sanitation facilities, together with inadequate availability of water for hygiene and unsafe drinking water. Globally, the problem is deteriorating as cities and populations grow, and the need for water increase in agriculture, industry and households.

Water is critical to food production. While the majority of agriculture is rain-fed, irrigated agriculture provides some 40 per cent of the worlds food and consumes 75 per cent of worlds freshwater resources (The Gender and Water Development Report, 2003). Supplies of freshwater are increasingly threatened by population growth, changing lifestyles (use of more water per capita) and pollution. A lack of water has driven up the use of wastewater for agricultural production in poor urban and rural communities. More than 10% of people worldwide consume foods irrigated by wastewater that can contain chemicals or disease-causing organisms. Also, current rapid industrialization in developing countries has caused levels of heavy metals and pollutants to significantly increase in the last couple of decades, especially those from aquatic ecosystems. For example, according to an investigation conducted by the State Environmental Protection Administration, much of the Pearl River Delta in China has been polluted by heavy metals and that 40 per cent of farms and vegetable plots in the region had been polluted by these heavy metals (Wade, 2011).

Heavy metals pose a threat to the environment as they cannot be degraded and would remain in the soil and water for a long period of time. They produce their toxicity by forming complexes with proteins, in

which carboxylic (-COOH), amine (-NH2), and thiol (-SH) groups are involved. These modified biological molecules lose their ability to function properly and result in the malfunction or death of the cells. When metals bind to these groups, they inactivate important enzyme systems or affect protein structure, which is linked to the catalytic properties of enzymes (Adepoju-Bello and Alabi, 2005).

Many industries such as mining, electroplating and piping discharge waste which contains high levels of metal ions. For example, copper is widely present in metal-bearing industrial discharges, and if not treated can cause damage to a variety of aquatic fauna such as fish and invertebrates (Ng et al, 2002).

The presence of metal ions in domestic drinking water is also a problem in many countries. Lead accumulation causes major health problems such as immune disorders and lead-induced intelligence impairment, while iron contamination results in poor tasting and unattractive water with a distinctive reddish-brown colour (World Health Organisation, 1996). In fact, there was a case in 2009 where residents in Singapore had reported seeing iron contaminated reddish-brown coloured water coming out from taps (Kreamer, 2009). Thus, it can be seen that contamination of drinking water by corroded pipes can indeed be a cumbersome problem.

Various kinds of methods have been developed to purify contaminated water around the world, such as the invention of desalination plants and sedimentation (Lalov et al., 2000). However, such methods are not cost effective. Developing countries cannot afford expensive filtration systems to treat wastewater it is difficult for them (and other developing countries) to obtain pure drinking water.

Hence, scientists have explored alternatives which are more cost effective. One popular alternative is the biosorption of metal ions by metabolically inactive non-living biomass of microbial or plant origin. Due to their unique chemical composition, metabolically inactive dead biomass sequesters metal ions, by forming metal complexes from a solution and removing the necessity to maintain special growthsupporting conditions (Ahluwalia and Goyal, 2006).

Another group of researchers found that shells of crustaceans such as crabs and shrimp can be used to remove heavy metals. This is mainly because their shells are made up of the material chitin which has the ability to adsorb toxic metals (Karthikeyan et al., 2005). Seashells have also been tested for their ability to remove zinc, lead, cadmium and iron (Reilly, 2009). Researchers found that flooding ground shells with highly contaminated water would cause the metals to be removed by the shell. Shells consist of aragonite, a mineral that is found to swap its calcium ions in exchange for heavy metal ions. The metals trapped are in a solid state and are harmless towards the environment.

This study explores the feasibility of constructing a filter from low cost and easily available material which can be used to remove heavy metal ions. The ability of three types of clam shell (mussel, lala clam and blood cockles) in removing copper(II), iron(III) and lead(II) ion was investigated and the most effective shell was used to construct the prototype. If successful, such a filter can be used in developing countries to help alleviate the problem of access to clean water caused by heavy metal pollution.

HYPOTHESES

1) All three types of shells are able to remove metal ions.2) The prototype constructed using clam shell is effec-tive in removing metal ions from contaminated water.

MATERIALS AND METHODS

MaterialsShells of lala clam, blood cockles and mussels were collected. The shells were washed with deionised water and dried in an oven at 70C for 24 hours. The solutions containing various concentrations of copper(II) ion, lead(II) ion and iron(III) ion were prepared from copper(II) sulfate, lead(II) nitrate and iron(III) nitrate respectively.

Preliminary studies:

1) To investigate effectiveness of removing metal ions with shells:0.5g of each type of shell was added to 50ml of 50ppm metal ion solution. The mixture was stirred on a magnetic stirrer for 60 min, after which it was filtered. The filtrate was analysed for the concentration of metal ion remaining using a AA spectrophotometer (AA 6300 Shimadzu) for lead (II) and a colorimeter (HACH, DR/890) for copper (II) and iron(III) ion. A control containing same volume of metal ion solution but without shell was subjected to the same experimental conditions.

2) Effect of pH on removal of metal ionsThe pH of metal ion solution was adjusted to 2 or 5 using Nitric acid (HNO3) or Sodium hydroxide (NaOH). pH above 5 was not studied as the metal ions were observed to precipitate out as metal hydroxide at pH greater than 5.

50ml of the solution with the desired pH was stirred with 0.5g of shell for 60min. After 60 min, the mixture was filtered and the metal ion remaining in the filtrate determined.

Figure 2: Removal of lead (II) ion at different pH

Results and discussion

Analysis for removal of Copper (II) ions at pH 2As shown in figure 1, all three types of shell are able to remove Cu2+ ions, blood cockles being the most effective (87.2%), followed closely by lala clam (80.6%) then by mussels (33.4%). No significant difference is seen between the effectiveness of removal by lala and blood cockles.

Analysis for removal of Copper (II) ions at pH 5At pH 5 however, all three types of shell show similar effectiveness in the removal of Cu2+ ions, with mussel shells showing the highest percentage of removal (97.8%), followed very closely by blood cockles (97.4%) and lala clam shells (95.3%). Unlike pH 2, there is no significant difference among the effectiveness of removal by the 3 types of shell at pH 5. The removal of copper (II) ion is more effective at pH 5 than at pH 2.

Analysis for removal of lead (II) ion at pH 2 As figure 2 shows, all three types of shell are able to remove Pb2+ ions, blood cockles showing the greatest % removal (99.5%), followed closely by lala clam (99.4%) then by mussels (95.4%).

Analysis for removal of lead (II) ion at pH 5Figure 2 shows that the removal of Pb2+ ions by all 3 types of shell at pH 5 is very effective, with the percentage removed being close to 100%. Blood cockles showed the greatest % removal (99.3%), followed by clam shells (99.2%), and finally by mussel shells (99.0%). No significant difference is seen among the effectiveness of removal of the three types of shells as the error bars overlap.

Analysis for removal of iron (III) ion at pH 2 All 3 types of shells are effective in removing iron(III) ions, with percentage removal of at least 95% for all types of shell. The percentage removal is the highest for mussel (98.9%), followed by blood cockles (98.6%) and lala clam (97.7%).

Analysis for removal of iron (III) ion at pH 5 Lala clam showed the greatest percentage removal (96.7%), followed by blood cockles (95.8%), and finally by mussel shells (92.1%). The trend observed here is similar to that observed for the removal of lead(II) at pH 5, where mussel shells is least effective.

Discussion: Lala clam and blood cockle shells are effective in removing all three types of metal ions at both pH studied. Mussel shell on the other hand is not as effective in removing copper(II) ion and lead(II) ion at pH 2, and not as effective in removing iron(III) ion at pH 5.

Clam shells are able to remove metal ions effectively due to the presence of aragonite, a biogenic form of calcium carbonate, which is able to readily swap its calcium ions in exchange for heavy metal ions. The equation is:CaCO3 + M2+ MCO3 + Ca2+

The difference in the ability of different shells in removing metal ions is likely due to the difference in the composition of the shell as the amount of calcium carbonate may vary in different types of shell. To ascertain whether the ability to remove metal ions is related to the amount of calcium carbonate, experiments were carried out to compare the calcium carbonate content in each type of shell. This was carried out by first reacting a fixed mass of shell with excess hydrochloric acid and titrating the unreacted acid with standard sodium hydroxide. Results show that mussel shell has the lowest percentage of calcium carbonate (84.3%), followed by blood cockles (94.4%) and lala clam (95.2%). Hence it is likely that mussel shell was less effective as it contains a lower percentage of calcium carbonate than the other two types of shell.

To further validate the aforementioned hypothesis, tests were also carried out with pure calcium carbonate

Figure 3: Removal of iron(III) ion by clam shells at different pHFigure 1: Removal of copper (II) ion by clam shells at different pH

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INTRODUCTION

Access to clean water is a universal human right. Unfortunately, around 1.1 billion people globally do not have access to improved water supply sources whereas 2.4 billion people do not have access to any type of improved sanitation facility (WHO-UNICEF, 2000). The most affected are the populations in developing countries, living in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants. The people from these countries have to travel great distances to collect water every day, from water sources that are often polluted. The time spent on the collection of water could have been spent on more productive work for them to earn a living. According to the United Nations Development Programme (2006), 443 million school days are lost each year due to water-related diseases. Falling ill due to water related diseases also further reduces peoples ability to do work and completing education. According to WHO-UNICEF (2000), about 2 million people die every year due to diarrhoeal diseases and most of them are children less than 5 years of age. 88% of the diarrhoeal diseases are due to a lack of access to sanitation facilities, together with inadequate availability of water for hygiene and unsafe drinking water. Globally, the problem is deteriorating as cities and populations grow, and the need for water increase in agriculture, industry and households.

Water is critical to food production. While the majority of agriculture is rain-fed, irrigated agriculture provides some 40 per cent of the worlds food and consumes 75 per cent of worlds freshwater resources (The Gender and Water Development Report, 2003). Supplies of freshwater are increasingly threatened by population growth, changing lifestyles (use of more water per capita) and pollution. A lack of water has driven up the use of wastewater for agricultural production in poor urban and rural communities. More than 10% of people worldwide consume foods irrigated by wastewater that can contain chemicals or disease-causing organisms. Also, current rapid industrialization in developing countries has caused levels of heavy metals and pollutants to significantly increase in the last couple of decades, especially those from aquatic ecosystems. For example, according to an investigation conducted by the State Environmental Protection Administration, much of the Pearl River Delta in China has been polluted by heavy metals and that 40 per cent of farms and vegetable plots in the region had been polluted by these heavy metals (Wade, 2011).

Heavy metals pose a threat to the environment as they cannot be degraded and would remain in the soil and water for a long period of time. They produce their toxicity by forming complexes with proteins, in

which carboxylic (-COOH), amine (-NH2), and thiol (-SH) groups are involved. These modified biological molecules lose their ability to function properly and result in the malfunction or death of the cells. When metals bind to these groups, they inactivate important enzyme systems or affect protein structure, which is linked to the catalytic properties of enzymes (Adepoju-Bello and Alabi, 2005).

Many industries such as mining, electroplating and piping discharge waste which contains high levels of metal ions. For example, copper is widely present in metal-bearing industrial discharges, and if not treated can cause damage to a variety of aquatic fauna such as fish and invertebrates (Ng et al, 2002).

The presence of metal ions in domestic drinking water is also a problem in many countries. Lead accumulation causes major health problems such as immune disorders and lead-induced intelligence impairment, while iron contamination results in poor tasting and unattractive water with a distinctive reddish-brown colour (World Health Organisation, 1996). In fact, there was a case in 2009 where residents in Singapore had reported seeing iron contaminated reddish-brown coloured water coming out from taps (Kreamer, 2009). Thus, it can be seen that contamination of drinking water by corroded pipes can indeed be a cumbersome problem.

Various kinds of methods have been developed to purify contaminated water around the world, such as the invention of desalination plants and sedimentation (Lalov et al., 2000). However, such methods are not cost effective. Developing countries cannot afford expensive filtration systems to treat wastewater it is difficult for them (and other developing countries) to obtain pure drinking water.

Hence, scientists have explored alternatives which are more cost effective. One popular alternative is the biosorption of metal ions by metabolically inactive non-living biomass of microbial or plant origin. Due to their unique chemical composition, metabolically inactive dead biomass sequesters metal ions, by forming metal complexes from a solution and removing the necessity to maintain special growthsupporting conditions (Ahluwalia and Goyal, 2006).

Another group of researchers found that shells of crustaceans such as crabs and shrimp can be used to remove heavy metals. This is mainly because their shells are made up of the material chitin which has the ability to adsorb toxic metals (Karthikeyan et al., 2005). Seashells have also been tested for their ability to remove zinc, lead, cadmium and iron (Reilly, 2009). Researchers found that flooding ground shells with highly contaminated water would cause the metals to be removed by the shell. Shells consist of aragonite, a mineral that is found to swap its calcium ions in exchange for heavy metal ions. The metals trapped are in a solid state and are harmless towards the environment.

This study explores the feasibility of constructing a filter from low cost and easily available material which can be used to remove heavy metal ions. The ability of three types of clam shell (mussel, lala clam and blood cockles) in removing copper(II), iron(III) and lead(II) ion was investigated and the most effective shell was used to construct the prototype. If successful, such a filter can be used in developing countries to help alleviate the problem of access to clean water caused by heavy metal pollution.

HYPOTHESES

1) All three types of shells are able to remove metal ions.2) The prototype constructed using clam shell is effec-tive in removing metal ions from contaminated water.

MATERIALS AND METHODS

MaterialsShells of lala clam, blood cockles and mussels were collected. The shells were washed with deionised water and dried in an oven at 70C for 24 hours. The solutions containing various concentrations of copper(II) ion, lead(II) ion and iron(III) ion were prepared from copper(II) sulfate, lead(II) nitrate and iron(III) nitrate respectively.

Preliminary studies:

1) To investigate effectiveness of removing metal ions with shells:0.5g of each type of shell was added to 50ml of 50ppm metal ion solution. The mixture was stirred on a magnetic stirrer for 60 min, after which it was filtered. The filtrate was analysed for the concentration of metal ion remaining using a AA spectrophotometer (AA 6300 Shimadzu) for lead (II) and a colorimeter (HACH, DR/890) for copper (II) and iron(III) ion. A control containing same volume of metal ion solution but without shell was subjected to the same experimental conditions.

2) Effect of pH on removal of metal ionsThe pH of metal ion solution was adjusted to 2 or 5 using Nitric acid (HNO3) or Sodium hydroxide (NaOH). pH above 5 was not studied as the metal ions were observed to precipitate out as metal hydroxide at pH greater than 5.

50ml of the solution with the desired pH was stirred with 0.5g of shell for 60min. After 60 min, the mixture was filtered and the metal ion remaining in the filtrate determined.

at pH 5 under the same conditions as that conducted with the shell. Results are shown in figure 4

Figure 4 shows that the effectiveness of pure calcium carbonate is comparable to that of lala and blood cockle shells, both of which contain more than 90% calcium carbonate. This further suggests that calcium carbonate is the primary agent in the removal of metal ions.

CONSTRUCTION OF PROTOTYPE

4 different versions of prototype were created, with each version aiming to improve on its effectiveness and efficiency. Lala clams and blood cockles were selected because they generally outperformed mussels at the 2 pH values studied. As this prototype was developed with third world countries in mind, the emphasis was on simplicity and ease of construction. A recycled plastic water bottle was used to contain clam shell, with sand at the base to prevent turbidity, and a piece of cloth at the mouth of the bottle to prevent the shell from flowing out. To test the effectiveness of our prototype, 100ml of water spiked with Cu2+, Fe3+ and Pb2+ was poured through the filter. The initial concentrations of the metal ions were within the range of 10-40 ppm. The filtrate was then collected and analysed for the concentration of Cu2+, Fe3+ and Pb2+. This proces