TABLE OF CONTENTS
Contents Pages
Title page
Certification
Dedication
Acknowledgements
Table of Contents
CHAPTER ONE
1.0 Introduction
CHAPTER TWO
- Â Â Â Â Air pollution
2.1 Sources of Air Pollution
2.1.1Â Natural Sources
- Anthropogenic Sources
- Â Air pollutants
- Â Effects of Air pollution
2.3.1 Health Effects
- Environmental Effects
CHAPTER THREE
- Characteristics and Composition of Scrap Tyre
3.1 Thermal Decomposition of Scrap Tyre
- Burning of Scrap tyre
- Method of Recycling Waste Tyres
- Process conditions of Scrap Tyres
- Pyrolysis
3.4.2 Combustion
CHAPTER FOUR
- Summary and Conclusion
4.1 Summary
4.2 Conclusion
References
CHAPTER ONE
- INTRODUCTION
Air pollution is the introduction into the atmosphere of chemicals, particulates or biological materials that causes discomfort, disease or death to humans, damage other living organisms such as food crops, natural environment or built environment (http://en.wikipedia.org/wiki/Air_pollution)
A substance in the air that can be adverse to humans and the environment is known as an air pollutant. Pollutants can be in the form of solid particles, liquid droplets or gases. In addition they may be natural or man-made. Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly produced from a process such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulphur dioxide released from factories. Secondary pollutants are not emitted directly but are formed in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone-one of the many secondary pollutants that make up phytochemical smog. Some pollutants may be both primary and secondary; that is they are both emitted directly and formed from other primary pollutants (Rao et al., 2007).
Only in the EU, USA and Japan around 6 million tons per year of scrap tyres are produced. The huge quantity of waste tyres presently in the world will certainly increase in the future as the associated automotive industries grew. The disposal of scrap tyres becomes a serious environmental pollution. A large fraction of the scrap tyres is simply dumped in sites where they represent hazards such as diseases and accidental fires. Rubbers are not biologically degradable and this fact creates problems with their disposal. The impact of waste rubber in the environment can be minimized by recycling with material or energy recovery. However, during processing and moulding, the rubber materials are cross linked and therefore, they cannot be simply again softened and remoulded by heating (Chang, 1996).
For many years, landfill was the main practical means for dealing with the problem of waste tyres. However, land filling of tyres is declined as a disposal option, since tyres do not degrade easily in landfills, they are bulky, taking up vulnerable land fill space and preventing waste compaction. Open dumping may result in accidental fires with high pollution emissions. In the EU countries in 1990 the percentage of tyres discarded in landfills was 62% of all produced waste tyres, in 2000 about 35% and in 2006 (as it results from the EU legislation) this percentage will decrease to 0% (Arion et al., 2001).
