Chapter II
Review of Related Literature
This chapter presents the reviewed related literature that gave significant insights to this present study.
Classification of Wastes
The classification of wastes varies and depends country by country. Waste can be divided into many different types. The most common method of classification is by their physical, chemical, and biological characteristics.
.1. Solid Waste. Solid waste is broadly defined as including non-hazardous industrial, commercial land domestic refuse including household organic trash, street sweepings, hospital and institutional garbage, and construction wastes; generally sludge and human waste are regarded as a liquid waste problem outside the scope of MSW (Zerbock, 2003).These are waste materials that contain less than 70% water. Example of this type of waste are the domestic or household garbage, some industrial wastes, some mining wastes, and oil field wastes such as drill cuttings.
2. Liquid Waste. These are usually wastewaters that contain less than 1%. This type of waste may contain high concentration of dissolved salts and metals. Liquid wastes are often classified into two broad types: sewage and toxic wastes. Generally, there are various types of liquid waste generated in urban centers: human excreta, domestics wastes produced in households, hospital wastes, industrial effluents, agricultural liquid wastes and nuclear wastes. When improperly handled and disposed of, liquid wastes pose a serious threat to human health and the environment because of their ability to enter watersheds, pollute ground water and drinking water (US EPA, 2009).3. Sludge. It is a class of waste between liquid and solid. They usually contain between 3%and 25% solid, while the rest of the material is dissolved water.4. Hazardous Waste Hazardous wastes are wastes which, by themselves or after coming into contact with other wastes, have characteristics, such as chemical reactivity, toxicity,corrosiveness or a tendency to explode, that pose a risk to human health or theenvironment. Hazardous wastes are generated from a wide range of industrial,commercial, and agricultural.
Research Design extent, domestic activities. They may take the form of solids, liquids or sludges, and can pose both acute and chronic public health and environmental risks by lining and contouring the fill, compacting and planting the uppermost cover layer, diverting drainage, and selecting proper soil in sites not subject to flooding or high groundwater levels. The best soil for a landfill is clay because clay is less permeable than other types of soil.
Materials disposed of in a landfill can be further secured from leakage by solidifying them in materials such as cement, fly ash from power plants, asphalt, or organic polymers(Bassis, 2005)Landfills can also be shifted to another use after their capacities have been reached. The city of Evanston, Illinois, built a landfill up into a hill and the now-complete “Mt. Trashmore” is a ski area. Golf courses built over landfillsites are also increasingly common (Montgomery, 2000).B)Recycling or the 3R’sAnother method, which sets off before waste disposal is waste reduction through recycling or often coined as the 3 R’s: reuse, reduce, and recycle.On the local or regional level, reducing wastes is accomplished through these methods by source separation and subsequent material recovery. Currently, the United States recycles about 10% of its glass and 25%of its paper wastes; in countries such as Switzerland and the Netherlands, the proportion in the glass recycled approaches to 50% while Japan recycles 50%of its paper wastes (Montgomery, 2000).
Some countries, on the other hand, manage most of their solid waste through
Incinerators.Incineration, or the controlled burning of waste at high temperatures to produce steam and ash, is another waste disposal option and an alternative to landfilling (US Environmental Protection Agency, 2009).
Incinerators aredesigned for the destruction of wastes and are commonly employed in developednations who could afford the costs of the burning facilities, plus its operation andmaintenance (Mc Cracken, 2005).This type of waste disposal is the second largest disposal method in mostdeveloped countries and ranks next to landfills in the United States and the United Kingdom. In the UK, approximately 5% of household waste, 75 % of commercial lwaste and 2% of industrial waste is disposed of through this method (Baker,2005)
A further benefit of incineration can be realized if the heat generated thereby is recovered. For years, European cities have generated electricity using waste-disposal incinerators as sources of heat (Montgomery,2000).There are negative issues, however, in the use of this burning method and much of that circulate around its safety for the environment and to the human health. It is argued that the combustion process creates air pollution, ash, and waste water, all of which must be properly managed using technical monitoring, containment, and treatment systems. Harmful pollutants are released into the environment whenever these by-products are not controlled (US EPA, 2009).Operators of these facilities must be well-trained and certified to ensure proper management.(http://www.scribd.com/doc/24935162/Review-of-related-literature-waste-and-waste-managment)
Waste Prevention and Minimization
Prevention means eliminating or reducing the quantity of waste which is produced in the first place, thus reducing the quantity of waste which must be managed. Prevention can take the form of reducing the quantities of materials used in a process or reducing the quantity of harmful materials which may be contained in a product.
Prevention can also include the reuse of products. Prevention is the most desirable waste management option as it eliminates the need for handling, transporting, recycling or disposal of waste. It provides the highest level of environmental protection by optimizing the use of resources and by removing a potential source of pollution.Minimization includes any process or activity that avoids, reduces or eliminates waste at its source or results in re-use or recycling. It can be difficult to draw a clear distinction between the terms quot;Prevention quot; and quot;Minimization quot;.Waste prevention and minimization measures can be applied at all stages in the life-cycle of a product including the production process, the marketing, distribution, or utilization stages, up to discarding the product at the end- of life stage. By examining each stage in the life cycle of a product, it may be possible that the quantities of waste produced at each stage can be reduced.
During the design stage of a product, consideration can be given to the types of materials to be used, the quantity of materials and the recyclability of the product once it reaches its end of life. The use of efficient processes in terms of energy and material requirements during the manufacture of a product are other important considerations. Consideration can also be given to minimizing the packaging for the product. ((http://www.globenet.org/preceup/pages/ang/chapitre/capitali/cas/nepal.htm)
Garbage Disposal System For Proper Waste Management
Actually, the solid wastes we throw in our garbage bins everyday can be classified into groups, this is called segregation. If you want to reduce, reuse and recycle, then it would be better for you to identify those wastes that can still be used from real garbage that needs to be thrown away.
Garbage are decomposable food wastes, these are excess foods, ingredients, etc., that are has no use for human consumption anymore. If you have a lawn and garden, making a compost pit can be a good way to make use of these wastes. This can be a good fertilizer for your garden plants.Proper waste disposal is very important in making sure that your place and environment is free from any waste that can cause health risks. If you want a clean and healthy environment, then you have to constantly clean your area, and put some tools and equipments like a garbage disposal to help you in keeping that area clean and free from harmful bacteria.
One place in our house that usually accumulates smelly wastes is our kitchen. Usually, garbage from excess food ingredients, rotten food, etc., goes straight to your kitchen's wastes bins, but this waste bins most of the time contains all things that cause bad odor in our kitchen. What is bad about this waste bins are that its bad smell can spread all over your house, and that would be really unsanitary.
Bad waste disposal in our kitchen can direct the waste straight into our plumbing system, causing a bigger trouble for you and your family. If you want to keep your house free form the bad smell of food waste and garbage, then it would be wise for you to have a proper garbage disposal.(http://ezinearticles.com/?Garbage-Disposal-System-For-Proper-Waste-Management&id=4432903)
Composting It is a natural process in which plant and other organic wastes are broken down biologically to produce a nutrient-rich material. At home, put yard and kitchen waste such as leaves, grass clippings, and fruit and vegetable scraps in a bin. This will
eventually decompose and produce a mixture that can be used for soil improvement in individual gardens. Municipalities can treat waste in the same way. Recycling Recycling is one of the best ways of waste management. It helps in reducing pollution, saving natural resources and conserving energy. Recycling newspapers, plastics, glass and aluminum also helps in saving money. Recycling other materials such as tires, batteries, asphalt, motor oil, etc. reduces pollution (otherwise these would end up in landfill or incinerator). In order to reduce trash, it is necessary to encourage and implement recycling at all levels of society.
Burning Waste
In cities that do not have enough land available for landfills, controlled burning of waste at high temperatures to produce steam and ash is a preferred waste disposal technique. Combustion reduces the volume of waste to be disposed significantly. Moreover, solid waste can provide for a continuously available and alternative source for generating energy through combustion. This energy can be channeled into useful purposes. (http://www.ehow.com/way_5701500_proper-waste-disposal.html)
Review of Related Literature
This chapter presents the reviewed related literature that gave significant insights to this present study.
Classification of Wastes
The classification of wastes varies and depends country by country. Waste can be divided into many different types. The most common method of classification is by their physical, chemical, and biological characteristics.
.1. Solid Waste. Solid waste is broadly defined as including non-hazardous industrial, commercial land domestic refuse including household organic trash, street sweepings, hospital and institutional garbage, and construction wastes; generally sludge and human waste are regarded as a liquid waste problem outside the scope of MSW (Zerbock, 2003).These are waste materials that contain less than 70% water. Example of this type of waste are the domestic or household garbage, some industrial wastes, some mining wastes, and oil field wastes such as drill cuttings.
2. Liquid Waste. These are usually wastewaters that contain less than 1%. This type of waste may contain high concentration of dissolved salts and metals. Liquid wastes are often classified into two broad types: sewage and toxic wastes. Generally, there are various types of liquid waste generated in urban centers: human excreta, domestics wastes produced in households, hospital wastes, industrial effluents, agricultural liquid wastes and nuclear wastes. When improperly handled and disposed of, liquid wastes pose a serious threat to human health and the environment because of their ability to enter watersheds, pollute ground water and drinking water (US EPA, 2009).3. Sludge. It is a class of waste between liquid and solid. They usually contain between 3%and 25% solid, while the rest of the material is dissolved water.4. Hazardous Waste Hazardous wastes are wastes which, by themselves or after coming into contact with other wastes, have characteristics, such as chemical reactivity, toxicity,corrosiveness or a tendency to explode, that pose a risk to human health or theenvironment. Hazardous wastes are generated from a wide range of industrial,commercial, and agricultural.
Research Design extent, domestic activities. They may take the form of solids, liquids or sludges, and can pose both acute and chronic public health and environmental risks by lining and contouring the fill, compacting and planting the uppermost cover layer, diverting drainage, and selecting proper soil in sites not subject to flooding or high groundwater levels. The best soil for a landfill is clay because clay is less permeable than other types of soil.
Materials disposed of in a landfill can be further secured from leakage by solidifying them in materials such as cement, fly ash from power plants, asphalt, or organic polymers(Bassis, 2005)Landfills can also be shifted to another use after their capacities have been reached. The city of Evanston, Illinois, built a landfill up into a hill and the now-complete “Mt. Trashmore” is a ski area. Golf courses built over landfillsites are also increasingly common (Montgomery, 2000).B)Recycling or the 3R’sAnother method, which sets off before waste disposal is waste reduction through recycling or often coined as the 3 R’s: reuse, reduce, and recycle.On the local or regional level, reducing wastes is accomplished through these methods by source separation and subsequent material recovery. Currently, the United States recycles about 10% of its glass and 25%of its paper wastes; in countries such as Switzerland and the Netherlands, the proportion in the glass recycled approaches to 50% while Japan recycles 50%of its paper wastes (Montgomery, 2000).
Some countries, on the other hand, manage most of their solid waste through
Incinerators.Incineration, or the controlled burning of waste at high temperatures to produce steam and ash, is another waste disposal option and an alternative to landfilling (US Environmental Protection Agency, 2009).
Incinerators aredesigned for the destruction of wastes and are commonly employed in developednations who could afford the costs of the burning facilities, plus its operation andmaintenance (Mc Cracken, 2005).This type of waste disposal is the second largest disposal method in mostdeveloped countries and ranks next to landfills in the United States and the United Kingdom. In the UK, approximately 5% of household waste, 75 % of commercial lwaste and 2% of industrial waste is disposed of through this method (Baker,2005)
A further benefit of incineration can be realized if the heat generated thereby is recovered. For years, European cities have generated electricity using waste-disposal incinerators as sources of heat (Montgomery,2000).There are negative issues, however, in the use of this burning method and much of that circulate around its safety for the environment and to the human health. It is argued that the combustion process creates air pollution, ash, and waste water, all of which must be properly managed using technical monitoring, containment, and treatment systems. Harmful pollutants are released into the environment whenever these by-products are not controlled (US EPA, 2009).Operators of these facilities must be well-trained and certified to ensure proper management.(http://www.scribd.com/doc/24935162/Review-of-related-literature-waste-and-waste-managment)
Waste Prevention and Minimization
Prevention means eliminating or reducing the quantity of waste which is produced in the first place, thus reducing the quantity of waste which must be managed. Prevention can take the form of reducing the quantities of materials used in a process or reducing the quantity of harmful materials which may be contained in a product.
Prevention can also include the reuse of products. Prevention is the most desirable waste management option as it eliminates the need for handling, transporting, recycling or disposal of waste. It provides the highest level of environmental protection by optimizing the use of resources and by removing a potential source of pollution.Minimization includes any process or activity that avoids, reduces or eliminates waste at its source or results in re-use or recycling. It can be difficult to draw a clear distinction between the terms quot;Prevention quot; and quot;Minimization quot;.Waste prevention and minimization measures can be applied at all stages in the life-cycle of a product including the production process, the marketing, distribution, or utilization stages, up to discarding the product at the end- of life stage. By examining each stage in the life cycle of a product, it may be possible that the quantities of waste produced at each stage can be reduced.
During the design stage of a product, consideration can be given to the types of materials to be used, the quantity of materials and the recyclability of the product once it reaches its end of life. The use of efficient processes in terms of energy and material requirements during the manufacture of a product are other important considerations. Consideration can also be given to minimizing the packaging for the product. ((http://www.globenet.org/preceup/pages/ang/chapitre/capitali/cas/nepal.htm)
Garbage Disposal System For Proper Waste Management
Actually, the solid wastes we throw in our garbage bins everyday can be classified into groups, this is called segregation. If you want to reduce, reuse and recycle, then it would be better for you to identify those wastes that can still be used from real garbage that needs to be thrown away.
Garbage are decomposable food wastes, these are excess foods, ingredients, etc., that are has no use for human consumption anymore. If you have a lawn and garden, making a compost pit can be a good way to make use of these wastes. This can be a good fertilizer for your garden plants.Proper waste disposal is very important in making sure that your place and environment is free from any waste that can cause health risks. If you want a clean and healthy environment, then you have to constantly clean your area, and put some tools and equipments like a garbage disposal to help you in keeping that area clean and free from harmful bacteria.
One place in our house that usually accumulates smelly wastes is our kitchen. Usually, garbage from excess food ingredients, rotten food, etc., goes straight to your kitchen's wastes bins, but this waste bins most of the time contains all things that cause bad odor in our kitchen. What is bad about this waste bins are that its bad smell can spread all over your house, and that would be really unsanitary.
Bad waste disposal in our kitchen can direct the waste straight into our plumbing system, causing a bigger trouble for you and your family. If you want to keep your house free form the bad smell of food waste and garbage, then it would be wise for you to have a proper garbage disposal.(http://ezinearticles.com/?Garbage-Disposal-System-For-Proper-Waste-Management&id=4432903)
Composting It is a natural process in which plant and other organic wastes are broken down biologically to produce a nutrient-rich material. At home, put yard and kitchen waste such as leaves, grass clippings, and fruit and vegetable scraps in a bin. This will
eventually decompose and produce a mixture that can be used for soil improvement in individual gardens. Municipalities can treat waste in the same way. Recycling Recycling is one of the best ways of waste management. It helps in reducing pollution, saving natural resources and conserving energy. Recycling newspapers, plastics, glass and aluminum also helps in saving money. Recycling other materials such as tires, batteries, asphalt, motor oil, etc. reduces pollution (otherwise these would end up in landfill or incinerator). In order to reduce trash, it is necessary to encourage and implement recycling at all levels of society.
Burning Waste
In cities that do not have enough land available for landfills, controlled burning of waste at high temperatures to produce steam and ash is a preferred waste disposal technique. Combustion reduces the volume of waste to be disposed significantly. Moreover, solid waste can provide for a continuously available and alternative source for generating energy through combustion. This energy can be channeled into useful purposes. (http://www.ehow.com/way_5701500_proper-waste-disposal.html)