TEXTBOOK OF INTRODUCTION TO ENVIRONMENTAL ENGINEERING (EAT 103/3) PDF

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CHAPTER 1 INTRODUCTION TO ENVIRONMENTAL ENGINEERING 1 1-1 OBJECTIVES The followings are the objectives of this chapter:- 9 Ability to describe basic environmental engineering components comprising air, water and land. 9 Ability to explain the concept of aspect and impact factors. 9 Ability to descri...

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CHAPTER 1 INTRODUCTION TO ENVIRONMENTAL ENGINEERING

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OBJECTIVES

The followings are the objectives of this chapter:9 9 9

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Ability to describe basic environmental engineering components comprising air, water and land. Ability to explain the concept of aspect and impact factors. Ability to describe and relate Environmental Quality Act 1974 to environmental issues.

INTRODUCTION TO ENVIRONMENTAL ENGINEERING

Environmental engineering is the application of science and engineering principles to manage and improve the environment. As such, topics discussed in relation to the environment normally include water, air and land resources. Sustainable development aims at providing healthy water, air and land for human habitation, for other organisms to survive, and to remediate polluted sites as well. Human interaction with the environment could give rise to an impact on the environment and sometimes is being adversely impacted by pollutants in the environment. A large amount of data will have to be interpreted in the light of the need for sustainable development. As such, environmental engineers will have to be conscious of and find viable ways to cope with such a situation. Environmental crisis is a crisis of the senses, imagination, and use of pertinent tools, that guide us in our ways of thinking, developing concepts, and postulating theories. In the context of sustainable development, aspect and impact factors affecting the environment are of prime importance in discussing the future of sustainable development. As such, any decision making process on environmental management must be based on both these factors. 1-2.1 THE ENVIRONMENT Simply stated, the environment is one’s surroundings. To the environmental engineer, the word environment may take on a wide definition and requires a global perception. It should not be a narrow definition dealing only with liquid, gaseous or solid materials within a treatment plant reactor, but it should go beyond that. Global environment comprises the atmosphere, hydrosphere, and lithosphere in which life sustaining resources of the earth are contained. The atmosphere , a mixture of gases extending outward from the surface of the earth, evolved from the elements of the earth that were gasified during its formation and metamorphosis. The hydrosphere consists of oceans, lakes, streams, and shallow groundwater bodies that interflow with surface water. The lithosphere is the soil mantle that wraps the core of the earth. The biosphere, a thin shell that encapsulates the earth, is made of the atmosphere and lithosphere adjacent to the surface of the earth, together with the hydrosphere. It is within the biosphere that the life forms of earth, including humans, live. Life sustaining materials

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in gaseous, liquid, and solid forms are cycled through the biosphere, providing sustenance to all living organisms. 1-2.2 POPULATION Growing population puts pressure on both the economic and environmental systems. It brings along a need for more food, fuel, water, and goods and services. As such, it is vital to discuss on the interaction of the aspects of demographic and environment. Population growth means more demand for good lifestyle. Above all, it creates a requirement for more investment to be committed to meet all these needs. Consequently there bounds to be a rise in economic activities, a direct impact on a lot more people, and an increasing burden on the ecosystem. However, this should not be a case for an argument to be made against population growth. If the environmental, economic and social carrying capacities of the system can cope with the demands, then it will be well and good. It must be emphasised that the purpose of an economy is to provide sufficient supplies of goods and services for the people and not to create more problems. However, there is one vital caveat: for the system to be sustainable it must have the capacity to generate enough wealth to provide for the necessary investments for the maintenance of the environment and the material requirements of the population as well. In moving towards an era in which environmental stability is a prime factor in economic and social survival, similar observations with the earlier transition from the agricultural age to that of the industrial one can be inferred. That transition became possible only when agricultural production was sufficient to support not only those living on the agricultural land, but also the new industrial population. 1-2.3 SUSTAINABLE DEVELOPMENT Population, economic development, and the environment are among the three important elements in the sustainability equation. Take one example: that of dealing with the unwanted waste products of development—not simply referring to solid industrial or domestic waste -but also various forms of water and air pollution generated by humans that contribute to the build-up of carbon dioxide and methane in the atmosphere. An ecologically satisfactory solution may be pursued in three ways: limiting economic activity and thereby cutting down on the waste generating process; investing in technologies that limit and render the waste harmless; or ensuring that population growth does not exceed the capacity of the economy to evolve in accordance with environmental requirements. If the first route is emphasised then this may well imply that we should move away from our present technologically oriented society and go for a simpler lifestyle. The problem is that it would have to be much simpler, and at a population density far lower and not to resort to draconian measures. It would also entail a very long period of adaptation. If the second route is chosen as the main solution, then policy makers must be fully committed to the cause. To deal with problems of waste through the wider application of technology, we will need large capital investments. In order to create this we will, in turn, need a level of industrial output that exceeds both consumption and economic requirements so that there will be enough money available for the investment in the necessary technologies. The snag here is that the higher the levels of industrial output required, the higher will be the generated waste. Thus we have the twin feedback loops to address in every system: a positive and a negative. The third route is to ensure that the population

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growth accords with the potential for environmentally sound economic development. Therefore, these are the concerns of those involved in demographic questions. Taking Malaysia as a case in point, her per capita generation rate of solid waste has been reported to be around 0.85-1.4 kg and it is continuously increasing. This generation rate of solid waste is rather alarming. Serious effort should be made to overcome or to prevent this generation rate so that it will not exceed the capacity available to treat it. An integrated approach should be taken in the decision making process and local authorities will have to gear up their plans to deal with the associated problems as they arise. In Johor Bahru for example, the population was rapidly increasing and subsequently posing a serious problem, like the piles and piles of solid wastes that are deposited. In the Johor Bahru region, WPI (Wilayah Pembangunan Iskandar) has been planned and developed that will offer more jobs in that particular area. As a possible impact, the population within this region will increase rapidly, and so will the amount of waste generation. 1-2.4 WATER Water is one of the resources required to sustain life and has long been suspected of being the source of many human illnesses. It was not until approximately 150 years ago that a concrete proof of disease transmission through water was established. In Malaysia for example a few rivers have been identified as highly polluted. Examples are Sungai Skudai and Sungai Juru. Assessments have shown that the impact of industrial area was the main contribution factor to this problem. So, in this regard, it is going to be a tough time for environmental engineers to ensure the attainment of sustainable development. For many years, the major consideration was to produce adequate supplies that were hygienically safe. However, the water sources have become increasingly polluted due to the increased industrial and agriculture activities. Pesticides used in agriculture pose the main threat to water sources. The public has been more precise in the demand for clean and healthy water as time passes by. As such environmental engineers are expected to produce acceptable treated water and maintain cleaner water resources. In water science for example, the management of groundwater is very important compared to others like precipitation. Environmental engineers will have to ensure that groundwater sources are free from pollutants. In Bangladesh for example, their sources of groundwater were heavily contaminated by arsenic. Therefore we have to look at and ensure the management system of groundwater sources is properly carried out. Today, water engineers are expected to produce treated waters that are free of colour, turbidity, taste, odour, nitrate, harmful metal ions, and a wide variety of organic chemicals such as pesticides and chlorinated solvents. At present, more than 85 scheduled chemicals are listed in the U.S Environmental Protection Agency’s drinking water standards, and the world health Organization lists over 100 scheduled chemicals in its guidelines for the acceptable quality of drinking water. Health problems associated with some of these chemicals include cancer, birth defects, central nervous system disorders, disruption of the endocrine system and heart disease. As population increases, the demand for water also increases at a much more rapid rate if the unchecked population growth is accompanied by improved living standards. Thus the combination of these factors is placing greater and greater stress on finding adequate sources of clean and healthy water. In many cases inferior-quality, and often polluted,

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water supplies are utilized to meet the demand. It is expected that this condition will continue and grow more complicated as the population and industrial development keep on growing.

1-2.5 WASTEWATER AND WATER POLLUTION CONTROL The disposal of human wastes has always posed a serious problem. With the development of urban areas, it has become necessary, from the aspects of public health and aesthetic considerations, to provide drainage or sewer systems to transport such wastes away from these areas. The normal repository was usually the nearest watercourse. It soon became apparent that rivers and other receiving bodies of water have a limited ability to handle waste materials without creating nuisance. This led to the development of purification or treatment facilities where chemists, biologists, and engineers have played important roles. Water quality managers are concerned with the controlling of pollution arising from human activities to ensure that water produced is suitable for its intended uses. Water quality management is crucial in handling water supply to the community. It is very important to know what level of waste is intolerable for a particular water body. To know how much waste can be tolerated by a water body, water quality managers must understand the type of pollutants discharged and the manner in which they affect water quality. Therefore a good knowledge on good water quality sources like the ones found in Sungai Kejor (in Belum, Perak) and Sungai Sedim (Kulim, Kedah) is important. Originally, the intent of water quality management was to protect the intended uses of a water body while using water as an economic means of waste disposal within the constraints of its assimilative capacity. Water is a natural resource and plays a significant role in human civilization. It has been long known that all natural bodies of water have the ability to oxidize organic matters without the resulting nuisance conditions, provided that the organic and nitrogen (primarily ammonia) loading are kept within the limits of the oxygen resources of the water. It is also known that certain levels of dissolved oxygen must be maintained at all times if certain forms of aquatic life are to be preserved. Many research works have been conducted to establish these limits. Such works require the combined efforts of biologists, chemists, and engineers to realise their values. 1-2.6 INDUSTRIAL AND HAZARDOUS WASTES Nowadays environmental engineers have to face a very tough challenge in dealing with environmental issues. Apart of that, they have to develop effective technologies to meet the demand of sustainable treatment techniques. The great variety of wastes produced from the industries and the introduction of wastes from new processes demand the knowledge of chemistry on the part of environmental engineers to find solutions to most of these problems. The problems associated with managing hazardous wastes are particularly complex. Over 100 millions tonnes of hazardous wastes are generated each year in the United States. The U.S Environmental Protection Agency has placed well over 1200 sites that are contaminated with hazardous chemicals on the National Priority or superfund list because of their potential threat to human health and the environment.

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In Malaysia, awareness on this matter is still lacking and requires close monitoring. The Sungai Gatom case is a good example where hazardous wastes had been treated in an improper manner. Aluminium dros which are very harmful had been dumped illegally in this river and that posed a serious danger to public health. As a result the government had to fork out RM1.3 million as the disposal cost to clear the river from the dros. 1-2.7 AIR POLLUTION AND GLOBAL ENVIRONMENTAL CHANGE Pollution of the atmosphere increases in almost direct ratio to the population density and is largely related to the products of combustion from plants, incinerators, and automobiles, including gases, fumes, and smokes arising from industrial processes. The resulting emission of NOX and SOX are of concern. However, the vehicles on the road keep on increasing, worsening situation further. The intensity of most air pollution problems is usually related to the amount of particulate matter emitted into the atmosphere. In general, visible particulate matter can be controlled by enforcing relevant regulations. However the present regulations should be standardised to international standards as they lack certain aspects to meet the demand of current solutions to this environmental problem. These regulations must be updated if they are to be more relevant to the present environmental conditions. The most serious situation develops when local conditions favour atmospheric inversions and the products of combustion and of industrial processing that are contained within a confined air mass. In cases where atmospheric inversions occur over metropolitan areas under cloudless skies, haze commonly called smog is produced in the atmosphere. Under such conditions the atmosphere is often highly irritating to the eyes and to the respiratory tract and is far too intense to be accounted for by the materials emitted to the atmosphere from the varying and separate sources. Research on this field has been extensive. Many theories are postulated with regard to this problem, but the consensus is that it is the photochemical action between oxides of nitrogen and unsaturated hydrocarbons from automobile exhaust gases combined with several products of health concern such as ozone, formaldehyde, and organic compounds of nitrogen that give rise to the condition. These substances can condense on particulate matter in the atmosphere to form fog. Knowledge of chemistry helps very much in finding the root cause of this matter. Motor vehicles, factories, and power plants are the main contributors to air pollution. Such pollutants can cause cancer or other serious health effects, such as reproductive or birth defects, damage to the immune system, and respiratory problems, or they may cause adverse effects to the environment itself. The 1990 Clean Air amendments list 188 toxic air pollutants that the U.S Environmental Protection Agency is required to regulate. These include particulate matter; halogen compounds such as tetrachloroethene, dichloromethane, and dioxin; heavy metals such as mercury, cadmium, and lead; volatile organic compounds such as benzene and toluene; and other hazardous compounds such as asbestos. Building materials and furnishings are likely to include toxic chemicals that may be slowly released. Asbestos and radon, products used for household cleaning and maintenance, personal care, or hobbies often contain volatile can also cause serious harm.

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It has become increasingly apparent in recent years that pollution problems are becoming more global in nature. Usually the impact of human activities significantly cause problem in environmental quality. Apparently, the human activities in one region have a significant impact and affected the quality of air at a much further region. This was true in the case of the radioactive fallout. Current concerns are on global warming and stratospheric ozone depletion. It is very important to grasp well the chemical principles involved to help us understand how these problems arise and how they could be solved. It has been shown that a complex photochemical reaction involving chlorofluorocarbons, emitted at the earth’s surface and transported to the stratosphere, is destroying the stratospheric ozone layer. This layer is important in protecting the earth’s surface from cancer-causing ultraviolet radiation. Because of this impact, chlorofluorocarbons are being banned from use globally and as such, replacement compounds are being sought. ‘Greenhouse gases’ are another issue being discussed globally. Gases such as carbon dioxide, methane, water vapour, CFC, oxides of nitrogen and ozone absorb thermal radiation near the earth’s surface. This reaction led to the phenomenon known as greenhouse gases. As populations increased, the concentrations of these gases are increasing as well in the earth’s atmosphere mainly due to human activities. Since they do trap heat trying to escape from the earth, they have potential for warming the earth, a process sometimes called global warming. Although there is a consensus on the reasons for increase on the concentrations of these gases, there is still an argument as to whether this will lead to a general increase in temperature. Much remains to be learned here, and the expanding knowledge on environmental engineering will enhance and contribute to a better understanding of this problem.

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INTRODUCTION TO ENVIRONMENTAL POLICY

The Environmental Quality Act 1974 with its latest amendment (2005) contains the guidelines related to environmental issues. It comprises legal matters on air, water, land and their impact on the environment. Aspect and impact factors are very important and play a vital role in protecting our environment. It must be realised that human activities will somehow impinge on the surroundings. Activities in factories for instance, are directly associated with the pollution of the environment. Factories producing paints discharge a lot of toxic substances and they will have to be dealt with properly to avoid the resultant negative impact to surroundings. Understanding of aspect and impact factors is a must for environmental engineers to meet the demand of sustainable development. As a result, we need clear guidelines to be closely followed in order to make sure our activities do not breach the existing laws and regulations. The Environmental Quality Act 1974 allows the Ministry of Natural Resources and Environment after consultation with the Environmental Quality Council to define objectionable noise and to prescribe standards for tolerable noise. However, regulations with numerical limits of permissible noise are currently not available. The Environmental Quality (Amendment) Act 1985 makes it mandatory for an Environmental Impact Assessment (EIA) on various activities ...