Chapter 9 Solid Wastes
What is not included in the definition of hazardous waste? This is called nonhazardous waste
*household waste*, agricultural waste used as fertilizer, mining overburden returned to the mine site, and certain wastes produced in the combustion of coal
LLRW is divided into class A,B,C. Which of these is the least toxic?
Class A Class C is most
What are the current options for disposal in the U.S.?
Landfills Waste Piles Land Treatment Underground injection wells
Table 9.2 Principal programs and goals of the resource Conservation Recovery Act
The resource Conservation Recovery act had three different sets of goals- one for solid waste, one for hazardous waste, and one for underground waste
Where are radioactive materials generated?
hospitals research/education establishments laboratories nuclear power plants nuclear fuel-cycle facilities
When are wastes characterizes as hazardous?
if they exhibit ignitability, corrosivity, reactivity, or toxicity
What is low level radioactive waste? (LLRW)
items contaminated with radioactive materials
What is the difference between a landfill and surface impoundment?
landfills: disposal facilities in which the waste is placed into or onto the land with cells and liners to collect leachate surface impoundment: storage units that are not an effective method for disposal
Are there more or less landfills in the US than there were in the 1980's?
less
What practices must operators of landfills abide by?
location - not where any flooding occurs; not by airports (birds attracted to landfill cause danger to aircraft) design - must avoid groundwater contamination; install liners and collect leachate Operation - must be covered daily with dirt and protected from wildlife/people getting in Monitoring - must install systems to detect groundwater contamination; methane gas monitored and controlled closure/post closure care - must maintain closure and non-leakage for 30 years after landfill closes
What are uranium mill tailings?
materials that remain after uranium metal has been separated from original ore that contain LLRW
What is excluded from the definition of solid waste?
solid or dissolved material in domestic sewage and industrial wastewater discharges
What is land treatment?
solid waste, like sludge from municipal sewage treatment plans, that is applied onto or incorporated into the soil surface Microbes break down hazardous toxins
Who oversees nonhazardous waste? Who oversees hazardous waste? Who oversees radioactive waste?
state and local governments EPA USNRC (United States Nuclear Regulatory Commission)
What are underground injection wells? What in particular is this used for?
steel and concrete encased shafts placed deep in the ground into which wastes are injected under pressure Used especially for oil and gas wells that are not hazardous
Benefits of a bioreactor landfill
1. accelerates stabilization of waste 2. creates more space 3. can store leachate
Four main processes used to treat solid wastes and one new way to treat solid wastes
1. incineration 2. heat treatment 3. solidification and stabilization 4. chemical treatment 5. biological treatment
Problems with having fewer landfills farther apart How did they deal with this?
1. increase in transfer of municipal waste 2. increase in the exporting of solid wastes from the developed to the developing countries -- they cannot afford to clean up if something goes wrong Making sure that countries were notified and have written consent of the transfer of municipal waste
Two advantages of treating hazardous solid waste with biological oxidation
1. inexpensive 2. can render hazardous waste nontoxic
Major techniques for minimizing the production of hazardous wastes
1. manage inventory and improve operations 2. modification of equipment to reduce waste and enhance recycling 3. production process changes - substitute nonhazardous for hazardous, eliminate leaks 4. recycle and reuse 5. treatment to reduce toxicity and volume - evaporation, incineration, compaction, chemical
How does chemical treatment work?
1. neutralized by diluted bleach or acidic wastes from other operations within a plant or 2. leach contaminants from soil and chemically convert them to less toxic substances
solidification/stabilization (in-situ vitrification)
1. plasma power
What are two benefits of heat treatments?
1. presence of heat can attract bacteria that further stabilize the contaminants 2. the soil does not need to be removed and transported elsewhere
Two functions of incineration of solid and hazardous waste
1. reduce volume 2. destroying certain toxic chemicals
Table 9.3 Examples of hazardous waste generated by business and industry
Industries that generate hazardous waste are: chemical manufacuturers, metal manufacturers, coal and petroleum manufacturers, vehicle shops, printing/paper, leather, construction, cleaning agents/cosmetic manufacturers, furniture and wood
What are waste piles?
Noncontanerized accumulations of insoluble, solid, nonflowing waste temporary storage
Figure 9.1 Cross section of a typical landfill and leachate-collection system - be able to draw
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Problem with incinerating plastics and products that contain chloride salts
Produces hydrochloric acid that is very corrosive
What is plasma power? (in situ vitrification)
Temperatures in excess of 7000 degrees melt contaminated soil or waste, producing a glass or sand-like residue Hazardous chemicals are reduced to their
Where are tailings handled?
They stay in place and are stabilized and provided with a cover to protect them from wind and water erosion Army Corps of Engineers has jurisdiction over their disposal
Where are transuranic wastes being disposed of?
Waste Isolation Pilot Plant (WIPP) a deep underground repository that is in a salt dome in New Mexico
What are municipal wastes?
everyday items that get thrown away by people or industry; batteries, clothing, furniture, cans/bottles, newspapers
What are Greyfields?
failing malls and strip malls that barely do any business Goal is to redevelop into vibrant city centers
What is a biological treatment landfill?
add moisture to the waste to allow decomposition from organisms
What is the "end of pipe" approach?
agencies and organizations responsible for protecting the environment accepted the wastes that were generated and sought to develop satisfactory methods for their treatment and disposal
What is the definition of solid waste?
any garbage, refuse, sludge from a waste treatment plant, air pollution control facility and other discarded material, including solid, liquid, semisolid, or gas resulting from industrial, commercial, mining and agricultural operations and from community activities
Define treatment of hazardous waste
any method that is designed to change the physical chemical or biological character or composition of a hazardous waste so as to neutralize it, recover energy or material resources from it, make it nonhazardous, or safer, and more easy to dispose of
When is incineration a primary method of disposal? Why?
communities that cant dispose into landfill because 1. resulting ash is more disposable 2. resulting ash is more stable 3. insoluble to rain so leaching into ground water is minimized
What are transuranic wastes (TRU)? Is this a radiologic hazard?
contain elements heavier than uranium that have high half life concentrations it is more of a chemical hazard
What is heat treatment used for?
contaminated soil Heat as steam is injected deep into the ground to expand and dry clay which evaporates or immobilizes the contaminants. This approach has been used for years enhance removal of oil from the ground
What is chemical treatment typically used for?
corrosive solids, such as lime or cement kiln dust
How are high level radioactive wastes disposed of?
deep geological repository - Yucca mountain example
Examples of high-level radioactive waste
depleted fuel removed from commercial nuclear power plants and fission product wastes that were produced in the process of purifying plutonium for nuclear weapons (239Pu)
What is the Brownfield Redevelopment Initiative?
designed to clean up and reuse abandoned industrial and commercial facilities in economically depressed areas in the U.S. Many used as parks or sites for new industrial buildings
What is the definition of disposal?
discharge of solid or liquid waste into land or water
Figure 9.3 Picture of how they dispose of hazardous waste
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Table 9.7: Acts related to management and disposal of solid waste
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Table 9.8 Acts related to managing and disposing of radioactive waste
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Figure 9.4 Disposal of radioactive waste picture - earth mounded concrete bunker
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Figure 9.6 Picture of concrete storage bunker for on-site storage of spent (depleted) fuel
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What does it mean when wastes are "listed" by the EPA?
they are associated with certain commercial chemical products that have been identified as hazardous to human health or the environment
What is mixed waste?
waste that contains both hazardous chemicals and radioactive materials