Effect on Environment
What is Waste?
Municipal solid waste (MSW) refers to the steam of garbage collected through community sanitation services. Medical wastes from hospitals and items that can be recycled are generally excluded from MSW used to generate electricity. Paper and yard wastes account for the largest share of the municipal waste stream, and much of this can be recycled directly or composted. Over 30% of MSW generated in the U.S. is recycled annually. The majority of the waste that isn't recycled is typically sent to landfills, MSW is referred to as a renewable power source. It mainly consists from renewable resources such as food, paper, and wood products, it also includes nonrenewable materials that come from fossil fuels, as an example tires and plastics. Recyclable materials are separate out, and then the remaining waste is fed into a combustion chamber to be burned. The heat released from the burning MSW is used to produce steam, which then turns a steam turbine to generate electricity.
Although power plants are regulated by both federal and state laws to protect human health and the environment, there is a wide variation of environmental impacts associated with power generation technologies. The purpose of the following section is to give consumers a better idea of the specific air, water, land, and solid waste impacts associated with MSW-fired electricity generation. Power plants that burn MSW are normally smaller than fossil fuel power plants but typically require a similar amount of water per unit of electricity generated. When water is removed from a lake or river, fish and other aquatic life can be killed, affecting those animals and people who depend on these resources. Similar to fossil fuel power plants, MSW power plants discharge used water. Pollutants build up in the water used in the power plant boiler and cooling system. In addition, the cooling water is considerably warmer when it is discharged than when it was taken. These water pollutants and the higher temperature of the discharged water can upon its release negatively affect water quality and aquatic life. This discharge usually requires a permit and is monitored.
Waste in General
Hazardous wastes are poisonous byproducts of manufacturing, farming, city septic systems, construction, automotive garages, laboratories, hospitals, and other industries.
An increase in world population and consumption has led to a rapid growth in the quantity of solid waste which needs to be disposed of. Anti- air and anti-water pollution measures have also led to an increase in solid waste. The safe disposal of spent nuclear fuels poses particular problems. It has been estimated that 3.5 tons of solid waste is thrown away for every man, women and child each year.
The simplest way to deal with the waste is in open dumping. Much of our waste has been used to landfill disused quarries but suitable sites are becoming harder to find. Incineration, which greatly reduces the bulk, is also used.
Waste in General
Landfill sites can be disused quarries or a natural pit. The purpose of a landfill is to bury the waste in such a way that it will be isolated from groundwater, will be kept dry and will not be in contact with air. Organic matter is decomposed by anaerobic bacteria to produce methane, which can also be collected and used as a fuel,, and hydrogen sulfide and organic acids. When a landfill closes, the site and the groundwater must be monitored for up to 30 years. The organic acids when leached out with rain water can transport heavy metal ions into the wider environment.
In 2007, Americans threw out about 570 billion pounds of municipal solid waste. Compared to other nations, the United States has a record of generating waste at an alarming rate. Home to only 4% of the global population, we are responsible for more than 30% of the planet’s total waste generation. Each American discards an average of more than 1,650 pounds of garbage every year, or approximately 4.6 pounds per person each day, nearly double the 1960 average of 2.7 pounds per day.
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- Municipal Solid Waste." EPA. Environmental Protection Agency, n.d. Web. 12 Dec. 2014
- Pearson Baccalaureate: Higher Level Chemistry for the IB Diploma." : Catrin Brown, Mike Ford : 9780435994402. N.p., n.d. Web. 12 Dec. 2014
Pros & Cons of Waste in our Envirnoment
Beginning with the pro's, waste can be burned, this produces waste of a more composition and reduces the bulk as most of the organic waste is converted into gases. The heat produced can be used to maintain the temperatures needed (800-1000 C) There are problems however as the carbon dioxide produced is a greenhouse gas and carbon monoxide produced during incomplete combustion of plastics is poisonous. The combustion of PVC poses a particular problem as the hydrogen chloride produces causes acid rain. It must be removed from the fumes before they are released into the atmosphere. It is important to control the temperature to reduce the production of dioxins.
Materials should be reused so that no waste is produced, if this is not possible, the best alternative is recycling as it reduces: the use of raw materials, the level of pollutants, energy costs, the need of land for waste disposal. Recycled materials tend to be a lower grade quality than new ones. As materials are sold to manufacturers it provides the local authorities who collect it with an extra source of income.
Recycling metals saves the Earth's reserves of the ores and reduces energy costs. The aluminum that comes from cans are worth recycling because of its resistance to corrosion and the high cost of the initial extraction process. Steel can be easily separated from other metals by the use of magnets and other metals can be separated by their difference in density. Recycled metals are used as alloys, which reduce the need to purify metals completely.
Plastics are heated in the absence of air when they split up into their monomers in a process known as pyrolysis. If recycling is used to be successful and self sustainable, the cost of recycling must be less than that needed to produce new materials. There are costs of in sorting different used plastics and melting them so that they can be reshaped. Mixtures of plastics are much weaker than the individual plastics so the recycled product is often of lower quality than the original and has a limited range of uses.
Due to largely to lax governmental regulation on an ever-growing chemical industry, everyday products that are used and thrown away contain more dangerous and health-affecting chemicals than ever before. More than 60,000 untested chemicals pervade the consumer products on our shelves and in our homes. Even those chemicals whose health implications are at this point clear, such as Biphenyl-A (BPA), commonly found in plastics like toys, are poorly regulated. The problem is that nationally we have no clear solution for dealing with waste.