Chapter 16: Solid and Hazardous Wastes
I.
Solid Wastes
a. Municipal solid wastes consists of solid materials discarded from
homes, office buildings, stores, restaurants, schools, hospitals,
prisons, libraries and other facilities.
b. Non-municipal solid wastes consists of solid wastes generated by
industry, agriculture, and mining
c. Sanitary landfills: the most common method of waste disposal,
involving compacting and burying wastes under shallow layer of soil.
Layers of compacted clay and plastic sheets prevent leachate (liquid
wastes) from seeping into ground water.
i. Problems with sanitary landfills: potential for methane gas to
seep out and cause explosions, accidental leaking of toxic
leachate, a lack of existing landfill space, and resistance to new
landfills near homes and businesses.
d. Mass burn incinerator a large furnace that burns all solid wastes
except for unburnable items such as refrigerators.
i. Problems: potential air pollution, difficulties in disposing of
toxic ash produced, high cost of process and difficulties
choosing incinerator sites.
e. Composting: using microbial action, organic solid waste (yard wastes,
food scraps) is transformed into material that, when added to soil,
improves its condition
II.
Reducing solid wastes
a. Source reduction: products are designed and manufactured in ways
that decrease the volume of solid wastes and the amount of
hazardous waste in the solid waste stream.
b. The volume of solid waste can be reduced through source reduction,
reuse of products, and recycling of materials. Recycling conserves
natural resources and is more environmentally benign than landfill
disposal but requires a market for recycled goods.
III.
IV.
c. Integrated waste management: a combination of the best wastes
management techniques into a consolidated program to deal
effectively with solid waste.
Hazardous waste
a. A discarded chemical that threatens human health or environment.
Hazardous chemicals may be solids, liquids, or gases and include a
variety of acids, dioxins, abandoned explosives, heavy metals,
infectious wastes, nerve gas, organic solvents, PCB’s, pesticides, and
radioactive substances.
i. Dioxins are hazardous chemicals formed as unwanted
byproducts during the combustion of many chlorine
compounds.
ii. PCB’s (polychlorinated biphenyls) are hazardous, oily
industrial chemicals composed of carbon, hydrogen, and
chlorine.
Managing hazardous wastes:
a. Resource Conservation and Recovery Act (RCRA): instructs the EPA
to identify hazardous waste and to provide guidelines and standards
for state’s hazardous waste management programs
b. Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) or Super Fund Act established a program
whose goal is to clean up abandoned and illegal toxic waste sites
across the United States.
c. The most effective approach to managing hazardous waste is source
reduction, reducing the amount and toxicity of hazardous materials
used in industrial processes. Source reduction relies on green
chemistry, a subdiscipline of chemistry in which commercially
important chemical processes are redesigned to reduce
environmental harm.
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Brownfield land
i. Property where the reuse of the land may be complicated by
the presence of hazardous materials ie gas stations, dry
cleaning stores, factories, mills, foundries