Required Text: Friis, Robert H. Essentials of Environmental Health, Jones and Bartlett Publishers, 2012

Waste Recycling

I have two of my classmate responses to  Questions you have to make comments about 3 sentences for each.

Required Text: Friis, Robert H. Essentials of Environmental Health, Jones and Bartlett Publishers, 2012

Waste Recycling

There is a lot of “buzz” about recycling and “going green”. According to your text, EPA defines recycling as the process of minimizing waste generation by recovering and reprocessing useable products that might otherwise become waste i.e. paper, bottles, aluminum cans etc. Therefore, regarding the term recycling, discuss:

a) What method(s) are used at your home/locale

b) What method(s) have you identified are used on-campus

I have two of my classmate responses to above Questions you have to make comments about 3 sentences for each.

C. T. 

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I live in a rather small-town west of here. Many would agree that we still live in the “stone ages” with some things they still see going on around the city. We recently got a new waste management company in our town who takes care of all trash collection. Unfortunately they do not offer roadside pick up to recycle. However, there are three separate trailers that have compartments in them to recycle. There is a man in charge of recycling in the city and he parks the trailers all over the county so people have an opportunity to recycle materials. Also, during the summer months, teenagers have the opportunity to work for the city and walk the roads picking up trash. Those materials are then separated and recycled.

Here on campus I have seen several types of recycling processes. The different waste cans to throw paper, or plastic in. I think it is very important to show students these techniques. It becomes a habit to some and they can teach others. Also, I witness many guys and girls using reusable water bottles instead of plastic bottles they then throw away. I myself use a container daily to save on water bottles and filling up the trash bin.

N. F. 

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a. Being from Louisville, there is more than one method of recycling. In the area of Louisville I’m from, recycling trucks and garbage trucks pass through my neighborhood on the same day of the week, but alternating weeks. There are also more than 10 recycling drop-off locations. Not all areas of Louisville supply both garbage and recycling services every week, so these recycling drop-off locations makes it easier for people of the city to contribute to the community and recycle.

b. Being at WKU for more than four years, on campus the only method of recycling I’ve seen is a can typically next to the trash can with a blue top that states it’s for recycling. However, being off campus for more than a year, recycling feels harder. My apartment complex has dumpsters for trash, but not for materials worth recycling. This is tough, but like in Louisville there are recycling drop off locations. These locations in Bowling Green though are specified by what is being recycled at the recycling drop-offs, which is very cool.

Final note, recycling is a choice. Whether an individual recycles all the time or not, it is his or her choice. It is recommended that we as a society should, so I do because I feel I am doing my part. Also, these recycling drop offs in both cities I find to be a smart idea, and the number of these facilities should be increased as needed.

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Chapter 12

Solid and Liquid Wastes

Learning Objectives

By the end of this chapter the reader will be able to:

• Describe trends in the production of solid waste

• Discuss methods for source reduction of solid waste

• Discuss the role of landfills for disposing of solid waste

• Describe methods for primary, secondary, and tertiary sewage treatment

• Discuss hazards of poorly designed solid waste disposal sites and improperly processed sewage

Problems Caused by Growing Volume of Waste

• Difficulties in disposal
• Dump sites being filled
• Increases in pollution of aquatic environments, e.g., waterways and oceans

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Municipal Solid Waste (MSW)

• This is trash or garbage.
• In 2008, the United States–residents, businesses, and institutions–produced approximately 250 million tons of MSW (before recycling).

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Source: Adapted and reprinted from US Environmental Protection Agency, Solid Waste and Emergency Response (5306P). Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2008. Washington, DC: US Environmental Protection Agency; 2009, p.1.

Figure 12-2 Municipal solid waste generation rates, 1960–2008.

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Components of the MSW Stream
(Examples)

• Packaging
• Furniture
• Clothing
• Bottles

• Food waste
• Papers
• Batteries
• Organic materials

Total MSW Generation (by Material), 2008–250 Million Tons (Before Recycling)

Source: Adapted and reprinted from U.S. Environmental Protection Agency, Solid Waste and Emergency Response (5306P). Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2008. Washington, DC: U.S. Environmental Protection Agency; 2009, p. 4.

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The Four Dimensions
of MSW Disposal

• Recycling
• Landfilling
• Composting
• Combustion

Major Components of MSW Management

Source: Reprinted from U.S. Department of Energy, Energy Information Administration, Office of Coal, Nuclear, Electric and Alternate Fuels. Available at: http://www.eia.doe.gov/cneaf/solar.renewables/renewable.energy.annual/backgrnd/fig8.htm. Accessed May 2, 2010.

EPA’s Hierarchy for Management of MSW

• From more favored to less favored
• Source reduction
• Recycling
• Disposal

Source Reduction

• Source reduction refers to “reducing the amount of waste created, reusing whenever possible, and then recycling what is left.”

Components of Source Reduction

• Two important components
• Waste reduction aims to reduce the amount of waste produced at the source.
• Waste recycling refers to reuse of materials in the waste.

Programs for Recycling Wastes

Source: Adapted and reprinted from U.S. Environmental Protection Agency, Recycle City, Dumptown Game. Available at: http://www.epa.gov/recyclecity/gameint.htm. Accessed March 25, 2010.

Recycling

• The EPA defines recycling (reuse) as the process of “Minimizing waste generation by recovering and reprocessing usable products that might otherwise become waste (i.e., recycling of aluminum cans, paper, and bottles, etc.).”

Advantages of Recycling

• Reduces emissions of greenhouse gases
• Prevents pollution generated by the use of new materials
• Decreases the amount of materials shipped to landfills
• Preserves natural resources
• Opens up new manufacturing employment opportunities
• Saves energy

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Recycling Rates

Source: Adapted and reprinted from U.S. Environmental Protection Agency, Solid Waste and Emergency Response (5306P). Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2008. Washington, DC: U.S. Environmental Protection Agency; 2009, pp. 2, 3.

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Composting

• “the aerobic biological decomposition of organic materials [e.g., leaves, grass, and food scraps] to produce a stable humus-like product….Biodegradation is a natural, ongoing biological process that is a common occurrence in both human-made and natural environments.”
• Produces a useful material that resembles soil and that can be used in gardening.

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Composting Success

• The state of Massachusetts has one of the most successful composting programs in the U.S.
• Yard and food waste are composted, preventing 37,500 tons of waste from entering the disposal process and saving approximately $2 million each year.

Landfill Design

• A landfill is composed of four major parts:
• a bottom liner
• a system for collecting leachates
• a cover
• an appropriate location that minimizes the contamination of groundwater by materials released from the site

Side View of a Landfill

Source: Adapted and reprinted from U.S. Department of Energy, U.S. Energy Information Administration. Energy explained. Available at: http://tonto.eia.doe.gov/energyexplained/images/landfill.gif. Accessed May 4, 2010.

How a Landfill Works

• The bottom is lined with a dense layer of clay and sealed with thick plastic sheeting to contain leaks of hazardous materials.
• A flexible membrane liner holds in toxic chemicals that might contaminate groundwater.
• A leachate sump collects leachates, which then can be subjected to further treatment.

How a Landfill Works (continued)

• Garbage is piled up in rows; bulldozers and rollers compact the garbage; at the end of the day, the newly added garbage is covered with soil and other materials.
• After the garbage is covered, anaerobic bacteria aid in the decomposition of organic materials and produce methane gas.

Dangers Associated with Landfills

• Air pollution and groundwater contamination
• Leachates, which may include:
• Toxic heavy metals
• Solvents and cleaning agents.
• Gases such as methane

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Gaseous Emissions from Landfills

• Methane, volatile organic compounds (VOCs), and other gases
• Methane vented from landfills poses a fire hazard and is a greenhouse gas.
• VOC emissions
• Potentially carcinogenic
• May cause complaints about odors and symptoms of respiratory irritation

Megafills

• Megafills take in from 5,000 to 10,000 tons of trash per day and serve regional needs for waste disposal.
• Tend to be more cost effective than incinerators for disposal of solid waste.

Federal Landfill Standards

Location restrictions

Composite liners requirements

Leachate collection and removal systems

Groundwater monitoring requirements

Closure and postclosure care requirements

Corrective action provisions

Financial assurance

Source: Adapted and reprinted from US Environmental Protection Agency. Municipal Solid Waste: Landfills. Available at: http://www.epa.gov/osw/nonhaz/minicipal/landfill.htm. Accessed March 25. 2010.

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Incineration

• Can be used to generate energy while at the same time reducing the volume and weight of waste.
• No attempt is made to separate the trash into components; at the high temperatures of incinerating plants, glass and aluminum in the trash melt.
• Metals from the residues of combustion can be recycled into scrap metal; remaining ash is deposited in landfills.

Disadvantages of Incineration

• Emissions may be potentially hazardous to human health and the environment.
• Toxic materials emitted may cause air pollution or be deposited on the land.

Disposal of Hazardous
Materials and Wastes

• Hazardous wastes are disposed of legally in the U.S. by:
• Discarding them on the surface of the land
• Storing them in slurry ponds
• Dumping them into landfills or into the ocean
• Incineration

Sources of Hazardous Wastes

• Hazardous materials used in the home–Pesticides, cleaning products, automotive products, painting supplies, and other flammable and nonflammable products
• Medical waste–Chemicals, infectious agents, and radioactive materials
• Industrial hazardous waste–Heavy metals from plating operations, toxic chemicals, solvents, and residues from the manufacture of pesticides

Sources of Hazardous Wastes (continued)

• Radioactive waste–Spent nuclear fuel and tailings from uranium processing
• Mining wastes and extraction wastes–Toxic chemicals left over from mining operations include acids and heavy metals.

Scope of the Hazardous
Waste Problem

• More than 400 million tons are generated worldwide on an annual basis.
• Developed world generates most of the toxic wastes.
• Some developing nations will take hazardous wastes for cash payments; this practice may endanger the health of the local population.

Uncontrolled Hazardous Waste Sites in the U.S.

• An estimated 40,000 of these sites have been reported to federal agencies.
• 1,300 sites are on the National Priorities List (NPL).
• Superfund legislation mandates the cleanup of hazardous waste sites.

Toxic Waste Dump and Workers in Protective Clothing

Source: Reprinted from CDC Public Health Image Library, ID #1193 and ID #1530. Available at: http://phil.cdc.gov/Phil/details.asp. Accessed March 25, 2010.

Impacts of Uncontrolled Sites

• Potential adverse human health effects
• High costs of cleanup
• Reductions in property values
• Potential ecological damage

Love Canal

• Was the former site for disposal of toxic wastes
• Later used for residential construction
• Became identified with hazardous chemical exposures and their possible harmful influences on human health
• Led to the creation of the Superfund

Medical Waste

• “any solid waste that is generated in the diagnosis, treatment, or immunization of human beings or animals, in research pertaining thereto, or in the production or testing of biologicals….”
• More than 3.5 million tons are produced annually in the U.S.

Definition of Sewage

• “The waste and wastewater produced by residential and commercial sources and discharged into sewers.”

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History of Sewage Disposal

• Romans constructed a sewage system and aqueducts.
• The Middle Ages were a time of regression for the sanitary disposal of sewage.
• During the 19th century, methods for the treatment of sewage began to improve.

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Modern Sewage Treatment
and Disposal

• Modern technology involves :
• Removing solids
• Deactivating microbes
• Producing wastewater that can be returned safely to waterways or in some cases can be reused or recycled.

Primary Stage of
Sewage Treatment

• The primary stage aims to remove large materials, which can be composted or shipped to landfills.

Secondary Stage of
Sewage Treatment

• Secondary processing promotes microbial digestion of organic material that remains in the sewage.
• Microorganisms that are present naturally in sewage or that may be added to enhance microbial action aid in the digestion of the liquor during aeration.

Tertiary Stage of
Sewage Treatment

• Tertiary (high-level) processing is directed at removal of remaining solids and microorganisms from the liquid portion of sewage.
• Various methods exist for high-level processing including filtration through sand and charcoal filters and deactivation of microorganisms (disinfection) by using chlorine or UV radiation.

Sewage Processing System

Primary Tank

Secondary Processing

Aeration

Empty Aeration Tank

Source: Author. Courtesy of the Irvine Ranch Water District, Irvine, California.

U.S. Sewage Requirements

• Most jurisdictions in the U.S. require that wastewater receive at least secondary treatment.
• Water that has received only primary treatment is not recommended for any use and generally needs secondary or tertiary treatment for common purposes such as landscape irrigation.

Other Methods for Sewage Disposal

• Composting toilets
• Septic systems

Hazards Posed by Animal Wastes

• Contamination from nutrients, organic materials, microorganisms, residues of medicines, and potentially toxic gases
• Workers in contact with livestock exposed to pathogenic microorganisms
• Creation of antibiotic-resistant bacteria that may endanger human health