Chapter 16

1. Waste Generation and Waste Disposal Chapter 16

2. Paper or Plastic? • Polystyrene – plastic polymer with high insulation value • Aka – styrofoam • Is harmful to environment • In response to public sentiment • Switch to paper cup… but is this really better? • Use cradle-to-grave or life-cycle analysis:

3. Paper or Plastic

4. Humans generate waste that other organisms cannot use… • Inputs – plant materials, nutrients, water, energy • Outputs – waste • Anything not useful or consumed and nonuseful products

5. Municipal Solid Waste • We live in a throw-away society • Planned obsolescence • Municipal solid waste - refuse collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings and hospitals • Varies by season of year, socioeconomic status of the individual generating the waste and geographic location within the country • Some stats:

6. Content of the Solid Waste Stream • Waste stream – the flow of solid waste that is recycled, incinerated, placed in a solid waste landfill, or disposed of in another way

7. Composition of Municipal Solid Waste… another analysis • 31% - paper • 33%- organic materials (yard waste, food scraps, wood) • 12%- plastic • 18%- durable goods (appliances, tires)

8. E-Waste • Electronic waste (E-waste) - televisions, computers, cell phones that contain toxic metals • Increasing rapidly • Great environmental effect • Little incentive to recycle • Voluntary programs • Concern – costs more to recycle • US exports e-waste to China

9. Reduce, Reuse, Recycle • Reduce- waste minimization or prevention • Source reduction – seeks to reduce waste by reducing the use of materials destined to become MSW • Other benefits: • Packaging is concern • Substitution • Reuse- reusing something like a disposable cup more than once • May involve repairing an existing object • Agents of reuse • Recycle- next slide

10. The 3rd R • Closed loop recycling vs. open-loop • In US - increased since 1975 • Zero-sort recycling programs • Benefits… • Requires more energy than reduce and reuse • Goal of Recycling?

12. Composting • Organic material (ie. food and yard waste) cause problems in landfills: • Compost- organic material that has decomposed under controlled conditions to produce an organic-rich material • Compostable material includes… • Meat/dairy usually not composted • Composting tips: • Simple vs. sophisticated • C:N ratio of 30:1 • Turn over compost regularly

14. Landfills • Open dumps – still common in developing world • Problems • Sanitary landfills- engineered ground facilities designed to hold MSW with as little contamination of the surrounding environment as possible • Leachate- the water that leaches through the solid waste and removes various chemical compounds with which it comes into contact

15. Sanitary Landfill

16. Sanitary Landfills • Costs: • Building landfill is very expensive • Tipping fee • Choosing a site for sanitary landfill: • Some requirements: • Siting is often controversial and can be politically charged • Some problems with landfills:

17. Incineration • Incineration- the process of burning waste materials to reduce its volume and mass and sometimes to generate electricity and heat • Ash – residual nonorganic material that does not combust during incineration • Bottom ash • Fly ash • Pollutants released included

18. How does incineration work?

19. Incineration • Waste-to-energy – when heat generated by incineration is used rather than released in the atmosphere

20. Hazardous Waste • Hazardous waste- liquid, solid, gaseous, or sludge waste material that is harmful to humans or ecosystems • Collection sites - must be staffed with specially trained personnel • Periodic collection held • Once collected - sorted into a number of categories • Hazardous waste must be treated before disposal

21. Laws • Resource Conservation and Recovery Act (RCRA) - designed to protect human health and the natural environment by reducing or eliminating hazardous waste • Also know as “cradle-to-grave” tracking • RCRA ensures that hazardous waste is tracked and properly disposed of • 1984 – Hazardous and Solid Waste Amendments (HSWA)

22. Laws • Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) • Also know as “Superfund” • Puts a tax on the chemical and petroleum industries • This revenue is used to cleanup … • Requires the federal government to respond directly to the release of substance that may pose a threat to human health or the environment • Problems:

23. Superfund Sites in US

24. Brownfields • Contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded • Includes: old factories, industrial areas and waterfronts, dry cleaners, gas stations, landfills, and rail yards • Critics: inadequate solution to contaminated locations in country

25. International Consequences • Municipalities and industries may send waste to countries with less stringent regulations • Examples: • Tugboat Break of Dawn (from NY in 1987) • Khian Sea (a Bahamian ship hired by Philly in 1986) • Mercury from India to PA

26. Life Cycle Analysis • Looks at the materials used and released throughout the lifetime of a product Life Cycle Analysis

27. Alternative Ways to Handle WasteIntegrated Waste Management • A method that seeks to develop as many options as possible, to reduce environmental harm and cost • Utilizes reduction, recycling, composting, landfills, and incineration • No single method works for everyone