Waste Generation and Waste Disposal

1. Waste Generation and Waste Disposal

2. Types of waste Waste= any unwanted item or substance resulting from a human activity or process • Municipal solid waste = from homes, institutions, small businesses • Industrial solid waste = from production of consumer goods, mining, petroleum extraction, agriculture (Most industrial waste in the US comes from mining operations) • Hazardous waste = toxic, chemically reactive, flammable, or corrosive • Wastewater = water used in homes, businesses, etc., and drained or flushed, plus runoff from streets

3. Municipal Solid Waste • Refuse collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings and hospitals.

4. Municipal solid waste generation • Average waste per person: 1. United States 2.0 kg/day(5lbs/day) 2. Canada 1.7 3. The Netherlands 1.4 • Germany and Sweden = least among developed nations: 0.9 kg/day • U.S. = “the throwaway society”

6. Of all the solid municipal waste produced in the United States, 31% is made up of paper.

7. E-Waste • Electronic waste (E-waste) televisions, computers, cell phones that contain toxic metals.

8. Waste generation in developing countries Open Dumping – Garbage is usually burned. Environmental Hazards: uncontrolled release of harmful materials, attraction of rodents, and odor.

9. Landfills • 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.

10. Landfills • In modern sanitary landfills, waste is buried or piled up so as to avoid contamination of the environment. • The Resource Conservation and Recovery Act (RCRA) specifies guidelines for how waste should be added to a landfill.

13. Methods of Solid Waste Disposal: Sanitary Landfills • Waste buried in the ground or carefully piled into mounds • Designed to prevent groundwater contamination and minimize soil and air pollution Did You Know?Regulations require that landfills be at least 6 m above the water table.

14. Drawbacks of landfills • Leachate will likely escape even from well-lined landfills, and can find its way to groundwater • Release greenhouse gases (methane and CO2) as wastes decompose • Dry conditions to combat leachate slow bacterial decomposition: trade-off • Finding sites is difficult: NIMBY opposition • Air pollutants (nitric and sulfur oxides and carbon dioxide) from trucks used to transport the wastes

15. Incineration • Incineration- the process of burning waste materials to reduce its volume and mass and sometimes to generate electricity and heat.

16. Incineration

17. Waste to energy • Many incinerators now generate electricity from waste combustion. • Waste to energy(WTE) facilities use heat from furnaces to boil water. Steam turns turbines and generators. • WTE is efficient and effective, but income from power is low and expense is high, so it takes many years to recoup the investment.

18. Benefits and Cost of Incineration

19. Energy from landfills • Landfills can harness energy, too. • Bacterial decomposition inside landfills produces methane, the main component of natural gas. • By collecting “landfill gas”: • Landfills can make extra money • Fuel is made available • Greenhouse gas methane is prevented from reaching atmosphere

20. Methods For Reducing Solid Waste • Becoming a Sustainable Society – We must utilize practices that produce the same yield with less input of energy. • It is more cost effective and more sustainable to reduce input or production of wastes and pollutants rather than create ways to remediate them or store them later. • Three R’s – Reduce, Reuse, Recycle. These methods not only reduce our overall input of wastes into the environment, but can also reduce the amount of energy used and greenhouse gas emissions released.

21. Reduce, Reuse, Recycle • Reduce- waste minimization or prevention (avoiding production of waste from mining processes and air pollution from energy production) • Reuse- reusing something like using reusable water bottles rather than purchasing single use plastic water bottles • Recycle- materials are collected and converted into raw materials and then used to produce new objects

22. Reduction is better than disposal • REDUCE:Source reduction, or preventing waste in the first place, is a better option than disposal. • Personal/consumer behavior: • Use fewer items • Reuse items • Buy less-packaged and longer-lived goods • Manufacturer behavior: • Make goods with less packaging • Make longer-lived goods • Adopt more-efficient production methods Did You Know?States with “bottle bills” (consumers receive a refund per returned bottle or can) have reduced their beverage container litter by 69–84% and total litter by 30–64%.

23. Reuse • Reusing items is a powerful way to reduce one’s waste. • There are simple ways to do this: • Buy used clothing, and donate used clothing • Bring your own cloth bags to grocery stores • Bring your own coffee mug to coffee shops • Use rechargeable batteries

24. Composting • The conversion of organic waste into mulch or humus by encouraging natural processes of decomposition (Yard trimmings and food scraps primarily vegetable-based) • Reduces a home’s waste stream • Produces great soil for gardening • Many communities now have municipally run composting programs.

25. Recycling In 2007, Americans recycled or composted nearly 1/3 of municipal solid waste, saving energy equivalent to 10 billion gallons of gas.

26. Recycling • Collecting materials that can be broken down and reprocessed in order to manufacture new items • Items are taken to materials recovery facilities (MRFs), where workers prepare them for reprocessing. • Once readied, these materials are used in manufacturing new goods.

27. Over 4,000 U.S. communities have “pay-as-you-throw” trash collection; people who waste more pay more. Eleven U.S. states have “bottle bills,” laws that mandate that consumers get money back for returning bottles and cans to where they were purchased. Financial incentives

28. Forces driving recycling • Businesses see opportunities to save money. • Entrepreneurs see opportunities for new businesses. • Municipalities desire to reduce waste. • People feel satisfaction in recycling responsibly. • In many cases the latter two are driving recycling, and many programs today are run at an economic loss.

29. Recycling For recycling to work, consumers must buy goods made from recycled materials: • Many paper products • Many glass and metal products • Some plastic products • Pages of our textbook

30. Growth of recycling Recycling has grown rapidly and can expand further.

31. Recycling rates by state

32. Closed-loop or Primary Recycling Materials are converted into new products of the same type

33. Open-loop or Secondary Recycling Materials may be converted into a different type of product

34. Recycling

35. Recycling Paper • CASE STUDY: • Over half of the tree harvest worldwide goes to produce paper • Paper represents over 30% of the MSW in the US • The production of paper requires large amounts energy and water • In the US, paper production is the third-leading industrial producer of pollutants and energy consumption • Paper production releases into the environment harmful chlorine compounds that are used to bleach the cellulose fibers • Making recycled paper uses 64% less energy and produces much less air and water pollution; however, recycled paper is more expensive to produce than virgin paper.

36. Great Pacific Garbage Patch Great Pacific Garbage Patch

37. Integrated Waste Management • A method that seeks to develop as many options as possible, to reduce environmental harm and cost. • Reduction, recycling, composting, landfills, and incineration are some ways IWM is utilized.

38. What Is Hazardous Waste? • Ignitable: Can catch fire • Corrosive: Can damage or destroy metals • Reactive: Chemically unstable; can explode or produce fumes when combined with water • Toxic: Harmful or fatal when inhaled, ingested, or touched

39. Hazardous waste • There are many types of hazardous waste. • Two are worst because they persist for a long time without breaking down: • Heavy metals • (mercury, lead, chromium, arsenic, cadmium, tin, copper — from industry, mining, consumer products) • Organic compounds • (synthetic pesticides, petroleum products, rubber, solvents, preservatives…)

40. Types of Hazardous Waste Did You Know?U.S. households threw out about 304 million electronic devices in 2005—most were still in working order. • Organic compounds: Can act as mutagens, carcinogens, teratogens, and endocrine disruptors • Heavy metals: Many cause neurological damage over time. • E-waste: Contains heavy metals and toxic chemicals, but mostly treated as conventional solid waste

41. Common Sources of Hazardous Waste

42. Illegal dumping Unscrupulous individuals or businesses sometimes illegally dump hazardous waste to avoid disposal fees.

43. Integrated Management of Hazardous Waste • INCLUDES: • Producing less • Recycling or reusing the waste • Converting waste to a less hazardous material

44. Converting to Less Hazardous Substances • Methods of detoxifying hazardous wastes include the following: • Chemical methods – chemical reactions that convert waste into compounds that are less toxic • Ex: Using Cyclodextrin (a type of sugar) to remove solvents and pesticides from soil and groundwater • Physical methods – Physically removing hazardous waste by using charcoal to filter out solid hazardous wastes • Biological methods – Using living organisms • Ex: Bioremediation – using bacteria or other micro-organisms to remove contaminants from solid or liquid hazardous waste • Ex: Phytoremediation – using plant species to absorb contaminants such as mercury, lead, pesticides, or organic solvents from soil and water • Incineration – High temperatures can convert the waste to less toxic materials, but this method creates toxic ash that must be stored in a hazardous waste landfill site.

45. Unfortunately the most common method of dealing with hazardous waste is simply storing it

46. Storing Hazardous Wastes • Burial on land is least expensive and is the most predominant method used in the US • It is common practice for US to ship some solid hazardous wastes, such as electronics to other countries for disposal (much of the global electronic waste ends up in developing countries, increasing these residents risk to toxic heavy metals)

47. Burying Hazardous Wastes What happened at Love Canal?

48. Hazardous waste: Disposal methods • Landfills: Special landfills with stricter regulations are used for hazardous waste.This method is used infrequently due to cost of building and maintaining these types of facilities. • Surface impoundments: Ponds lined with plastic and clay. Liquid hazardous waste evaporates, leaving residue. Can overflow with heavy rains and contaminate soil and nearby waterways. Groundwater contamination may occur if inadequate liners are used. • Deep-well injection: Hazardous waste is pumped deep underground into porous and stable rock formations, away from aquifers. Most common form used for liquid hazardous waste. Inexpensive and relatively safe. Limited areas that have geologic structure to be a deep well disposal site.

49. Hazardous waste: Surface impoundments • Really only for temporary storage; not ideal • Waste may overflow, blow out, vaporize, or leak

50. Hazardous waste: Deep-well injection Seems a good idea, but is not without risk: Waste can leak out into groundwater.