Solid and Hazardous Waste

Chapter 21

21-1 What Are Solid Waste and Hazardous Waste, and Why Are They Problems?

Concept 21-1 Solid waste represents pollution and unnecessary waste of resources, and hazardous waste contributes to pollution, natural capital degradation, health problems, and premature deaths.

Solid waste: any unwanted or discarded material we produce that is not a liquid or gas.

• Municipal solid waste (MSW): produced directly by homes and workplaces• often called garbage or trash

• Industrial solid waste: produced indirectly by industries that supply people with goods and services

We Throw Away Huge Amounts of Useful Things and Hazardous Materials

Hazardous or toxic waste: threatens human health or the environment because it is toxic, chemically active, corrosive or flammable.• Organic compounds (solvents, pesticides, PCB’s)

• Toxic heavy metals (lead, mercury, arsenic)

• Radioactive waste (nuclear power plants, weapons facilities)

Developed countries produce 80-90% of the world’s hazardous wastes• The U.S. produces much more than any other country• China could overtake us

We Throw Away Huge Amounts of Useful Things and Hazardous Materials

What Harmful Chemicals Are in Your Home?

Although technically hazardous wastes, the disposal of these chemicals are do not fall under government regulation.

However, care should still be taken when choosing a disposal method.

Two reasons to be concerned about the amount of waste we generate:

• At least 75% of waste is unnecessary and uses up our earth’s precious resources.

• Producing the products we use and throw away creates large amounts of air pollution, water pollution, land degradation, and even more waste.

We Throw Away Huge Amounts of Useful Things and Hazardous Materials

The United States produces about a third of the world’s solid waste and buries more than half of it in landfills.• About 98.5% is industrial solid waste.• The remaining 1.5% is MSW.

• About 55% of U.S. MSW is dumped into landfills, 30% is recycled or composted, and 15% is burned in incinerators.

Solid Waste in the United States

Source: http://www.epa.gov/msw/facts.htm

Solid Waste in the United States

21-2 How Should We Deal with Solid Waste?

Concept 21-2 A sustainable approach to solid waste is first to reduce it, then to reuse or recycle it, and finally to safely dispose of what is left.

Integrated Waste Management

Integrated Waste Management: Priorities for Dealing with Solid Waste

It is always best to prevent the production of waste than to deal with it once it has been created.• We will reference this again when discussing pollution

1st Priority – prevent waste generation 2nd Priority – reuse, recycle, compost materials Last priority – deal with the waste generated

The 3 “Rs” of waste reduction:

Reduce: consume less and not only save resources, but also save money.

Reuse: rely more on items that can be used over and over, or ones that can be fixed and used again.

Recycle: paper, glass, cans, plastics…and buy items made from recycled materials.

We Can Cut Solid Wastes by Reducing, Reusing, and Recycling

If you would like to add a 4th ”R”:• Refuse: to buy items that we really don’t need, or

ones that generate a lot of waste.

21-3 Why Is Reusing and Recycling Materials So Important?

Concept 21-3 Reusing items decreases the use of matter and energy resources and reduces pollution and natural capital degradation; recycling does so to a lesser degree.

Reuse: Important Way to Reduce Solid Waste, Pollution and to Save Money

Reuse: involves cleaning and using materials over and over increasing the lifespan of a product• Decreases the use of resources, decrease in energy

used, cuts pollution, creates jobs

Examples:• Yard sales, flea markets, secondhand stores, E-bay,

Craigslist, auctions• Salvaging automobiles parts• Rechargeable batteries

Refilling and reusing containers uses fewer resources and less energy, produces less waste, saves money, and creates jobs.• In Denmark and Canada’s Price Edward’s Island there is

a ban on all beverage containers that cannot be reused.• In Finland 95% of soft drink and alcoholic beverages are

refillable (Germany 75%).

Case Study:Use of Refillable Containers

We can use reusable shopping bags, food containers, shipping pallets, rechargeable batteries, and borrowing tools.• Many countries in Europe and Asia charge shoppers for

plastic bags.

Case Study:Use of Refillable Containers

Pre-consumer waste – waste generated in the manufacturing process• internal waste

Post-consumer waste – waste generated by consumer use of products• external waste• the waste we actually “see”

Recycling involves reprocessing discarded materials into new, useful products.

There Are Two Types of Waste That Can Be Recycled

Primary or closed loop recycling: materials are turned into new products of the same type.• Making paper with recycled paper, or new glass bottles out of

used glass bottles

Secondary recycling: materials are converted into different products.• Shredded tires used to resurface tracks• Pop bottles can be turned into

playground equipment or car seats

There Are Two Types of Recycling

We Can Mix or Separate Household Solid Wastes for Recycling

Materials-recovery facilities (MRFs) – MSW is sent to a MRF to pick out and sort the recyclable materials.• Uses lots of energy and man-power• Expensive

Source separation – households/businesses sort recyclables out of their own garbage• Incentive??• Fee-per-bag – households/

businesses charged for each trash bag picked up, but no charge for recycling

Composting biodegradable organic waste is a way to recycle the yard trimmings and food wastes that would be sent to a landfill.

Composting mimics nature by recycling plant nutrients to the soil.

We Can Copy Nature and Recycle Biodegradable Solid Wastes

Case Study:Recycling Paper

55% of the world’s tree harvest is for making paper. Paper (especially newspaper and cardboard) is very

easy to recycle:• Removing ink and/or glue, converting it back to pulp,

bleaching it white, and press it into paper Making recycled paper vs. production new paper• 64% less energy use• 35% less water pollution• 74% less air pollution• Doesn’t cut down any trees!

Recycling many plastics is chemically and economically difficult.• Many plastics are hard to isolate from other wastes.• Recovering plastic resins does not yield much material.• The cost of new plastic is lower than recycled due to low

fossil fuel costs.

Case Study:Recycling Plastics

Case Study:Recycling Plastics

Trade-Offs: Recycling, Advantages and Disadvantages

21-4 The Advantages and Disadvantages of Burning or Burying Solid Waste

Concept 21-4 Technologies for burning and burying solid wastes are well developed, but burning contributes to pollution and greenhouse gas emissions, and buried wastes eventually contribute to pollution and land degradation.

Globally, MSW is burned in more than 600 large waste-to-energy incinerators, which boil water to make steam for heating water, or for production of electricity.• 98 of them in the U.S.• A few European countries incinerate most of their MSW.

• Great Britain burns about 90% of its “rubbish”

The ash left over after the incineration process must still be disposed of in a landfill.• Takes up 90% LESS space• However, now it is considered hazardous waste.

Burning Solid Waste Has Advantages and Disadvantages

Solutions: A Waste-to-Energy Incinerator with Pollution Controls

Greater Detroit Resource Recovery Facility / Incinerator

Solutions: A Waste-to-Energy Incinerator with Pollution Controls

Trade-Offs: Incineration, Advantages and Disadvantages

To be economically feasible, incinerators must be fed huge amounts of waste every day.• Encourages trash

production• Discourages recycling

Many proposed projects have been cancelled:

• High costs• Pollution concerns

Most of the world’s MSW is buried in landfills that eventually are expected to leak toxic liquids into the soil and underlying aquifers.

• Open dumps: fields or holes in the ground where garbage is deposited and sometimes covered with soil/clay. Mostly used in developing countries.

• Sanitary landfills: solid wastes are spread out in thin layers, compacted and covered daily with a fresh layer of clay or plastic foam. The bottom is also sealed with layers of clay and synthetic liners.

Burying Solid Waste Has Advantages and Disadvantages

Burying Solid Waste Has Advantages and Disadvantages

2 problematic substances created by the disposal of waste in landfills are:

Leachate – water that accumulates chemicals as it trickles through the wastes• Can contaminate groundwater if it leaks out of the landfill• Leachate is pumped out the bottom of the landfill and is

treated to rid it of toxic chemicals

Methane – a gas given off by the decomposition of the organic material• Methane gas recover wells collect the gas as it is created• Methane is burned to create electricity

Burying Solid Waste Has Advantages and Disadvantages

Solutions:State-of-the-Art Sanitary Landfill

Burying Solid Waste Has Advantages and Disadvantages

The location and types of landfills in Iowa.

Burying Solid Waste Has Advantages and Disadvantages

Trade-Offs:Sanitary Landfills, Advantages and Disadvantages