Ch. 24 Guided Notes (without graphs)

Chapter 24 Guided Notes
The United States generates the most solid waste of any country. We produce 4.4 pounds of solid waste per person per day. This creates a total of 229 million tons in one year.
Figure 24.1 Municipal Solid Waste

Nonmunicipal Solid Waste
• Mining: 75 %
• Agriculture: 13 %
• Industry: 9.5 %
Disposal of Sanitary Waste
Figure 24.2:

Landfills: Consists of a big hole where trash is placed, compacted, and covered with a layer of dirt. One problem is that they can pollute the ground with leachate and they produce explosive methane gas. Plastic is a problem because it will most likely never decompose in a landfill. Tires are a problem because they take up a large amount of space, they work their way to the top of a landfill and they are a fire hazard.
Incineration: This is the process of burning solid waste. The three types of incineration are mass burn, modular, and refuse derived fuel. Mass burn incinerators recover energy from the burning of the trash. Modular incinerators are smaller and burn all solid waste. In refused derived fuel incinerators, only the combustible parts of solid waste are burned. Problems with incineration include air pollution and the production of ash that must be disposed of.
Composting: This is when organic waste is converted into compost or mulch. This is then used to condition soil. Currently composting is used to recycle about 57 % of yard waste.
Source Reduction
Source reduction is when products are designed and manufactured in a way that decreases the volume of solid waste and the amount of hazardous waste in the solid waste stream. The Pollution Prevention Act of 1990 requires manufacturers to report their source reduction and recycling activities. Dematerialization works to decrease the size and weight of a product so that there is less waste.
Reusing
Reusing reduces waste. One example of reusing is refilling water bottles. Refillable water bottles are making a comeback in the United States.
Recycling
Pros: Conserves natural resources, reduces amount of waste in landfills, creates jobs
Cons: Uses energy, generates pollution
Improvements: Recycling rates are on the rise and the United States recycles more of its waste than any other country in the world
Categories:
• Paper- The U.S. recycles 45 % of its paper. This is less than some other countries because old paper mills in the U.S. are not equipped to process recycled paper. New mills are being built to fix this problem.
• Glass- The U.S. recycles 26 % of its glass. Recycled glass is cheaper and can be used to create cullet.
• Aluminum- It takes less energy to make cans from recycled aluminum. The U.S. recycles 55 % of its aluminum cans.
• Other metals- Metals like gold, lead, iron, steel, silver and zinc. Waste metals from industry are easy to recycle. New steel products are made from an average of 56 % recycled steel.
• Plastics- Less than 20 % of plastic is recycled. Sometimes plastic is cheaper to make from raw materials than from recycled materials, making it unprofitable to recycle plastic.
• Tires- Old tires can be used to make asphalt for pavement. Currently 9 % of tires are recycled to make other products
Figure 24.12 Integrated Waste Management














Hazardous Wastes
Love Canal was a community near Niagara Falls that was built on an old toxic waste dump. The residents were getting sick and they called for action. They were evacuated so that the toxic wastes could be cleaned up.
Dioxins: A group of compounds created as a by-product of the combustion of chlorine. Dioxins cause cancer and are emitted by smoke.
PCBs: A group of chemicals that are composed of carbon, hydrogen, chlorine. They were used in industrial processes for many years. They can cause kidney and liver damage. They can be destroyed by incineration or through decomposition by bacteria.