Download presentation
Presentation is loading. Please wait.
Published byDwayne Jenkins Modified over 8 years ago
1
WASTING RESOURCES Solid waste: any unwanted or discarded material we produce that is not a liquid or gas. – Municipal solid waste (MSW): produce directly from homes. – Industrial solid waste: produced indirectly by industries that supply people with goods and services. Hazardous (toxic) waste: threatens human health or the environment because it is toxic, chemically active, corrosive or flammable.
2
WASTING RESOURCES 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.
3
LD 50 – lethal dose 50% Add a certain chemical until 50% of organisms die That amount is then dropped by an order of 10, or 100, or 1000 and called EPA limit – PPM – PPB – PPT – PPQ
4
Managing Waste 1. Minimizing the amount of waste we generate (source reduction) (preferred) 2. Recovering waste materials and finding ways to recycle them 3. Disposing of waste safely and effectively
5
Municipal Solid Waste
6
Municipal solid waste generation Plastic and paper products have been growing faster than other types of waste.
7
Landfills facilities designed to hold MSW – waste is buried or piled up so as to avoid contamination of the environment Resource Conservation and Recovery Act (RCRA) specifies guidelines for how waste should be added to a landfill – Cradle to grave Leachate- the water that leaches through the solid waste and removes various chemical compounds with which it comes into contact
8
Sanitary landfill
9
Sand When landfill is full, layers of soil and clay seal in trash Methane storage and compressor building Leachate storage tank Leachate monitoring well Groundwater monitoring well Electricity generator building Leachate treatment system Methane gas recovery well Compacted solid waste Leachate pipes Leachate pumped up to storage tank for safe disposal Groundwater Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill Topsoil Sand Clay Subsoil Probes to detect methane leaks Garbage Synthetic liner Sand Clay Pipes collect explosive methane as used as fuel to generate electricity
10
Reclaiming landfill sites Old landfills, capped and abandoned, can be reclaimed for other uses, including parks. Shown is Cesar Chavez Park in Berkeley, California.
11
Drawbacks of landfills Leachate will likely escape even from well-lined landfills. Dry conditions to combat leachate slow bacterial decomposition: trade-off Finding sites is difficult: NIMBY opposition – Not in my backyard syndrome
12
Landfills “Garbologist” William Rathje does archaeology in landfills to document our consumption and waste patterns. He’s found: Trash rots VERY slowly in landfills. Paper products take up 40% of landfill space. Plastic packaging is overrated as a waste problem.
13
Incineration A controlled process of burning mixed solid waste at extremely high temperatures Reduces volume by 90% Remaining ash disposed of at landfill Better than open-air burning, but… …can create new chemical compounds and emit toxic chemicals from the stacks Popular opposition to incinerators because of pollution
14
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.
15
WTE incineration
16
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
17
Reduction is better than disposal Source reduction, or preventing waste in the first place, is a better option than disposal. Use fewer items Reuse items Composting goods with less packaging Make longer-lived goods Adopt more-efficient production methods
18
Hazardous waste 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…)
19
Household hazardous waste Many communities organize pickups or collection centers for this waste. – Oils
20
Illegal dumping Unscrupulous individuals or businesses sometimes illegally dump hazardous waste to avoid disposal fees.
21
Hazardous waste: Disposal methods Landfills: Special landfills with stricter regulations are used for hazardous waste. Surface impoundments: Ponds lined with plastic and clay. Liquid hazardous waste evaporates, leaving residue. Deep-well injection: Hazardous waste is pumped deep underground into porous and stable rock formations, away from aquifers.
22
Hazardous waste: Surface impoundments Really only for temporary storage; not ideal Waste may overflow, blow out, vaporize, or leak
23
Hazardous waste: Deep-well injection Seems a good idea, but is not without risk: Waste can leak out into groundwater.
24
Radioactive waste A special type of hazardous waste Especially dangerous Much produced by military and hospitals; some by research institutions It’s extremely hard to find a place to dump it that is not opposed by local people: Yucca Mountain, Nevada WIPP, New Mexico
25
Superfund cleanup 1980: Comprehensive Environmental Response Compensation and Liability Act (CERCLA) established Superfund, administered by EPA – Commonly known as Superfund program
26
1953 Love Canal — There Is No “Away” Hooker Chemical dumps toxic waste Sold to Niagara Falls school board for $1 – Schools, homes built Birth defects, miscarriages President Jimmy Carter declared Love Canal a federal disaster area. – The area was abandoned in 1980 (left).
27
Minnesota Superfund Sites
28
Electronic Waste: A Growing Problem E-waste consists of toxic and hazardous waste such as PVC, lead, mercury, and cadmium. The U.S. produces almost half of the world's e-waste but only recycles about 10% of it.
29
A large amount of e-waste that is collected for recycling is shipped overseas for dismantling under horrific conditions, poisoning the people, land, air, and water in China, other Asian nations and to Ghana and Nigeria in western Africa https://www.youtube.com/watch?v=O- _ubuFhqQA https://www.youtube.com/watch?v=O- _ubuFhqQA
30
E-waste https://www.youtube.com/watch?v=dd_ZttK3 PuM https://www.youtube.com/watch?v=dd_ZttK3 PuM
31
Brownfields Contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded. Old factories, industrial areas and waterfronts, dry cleaners, gas stations, landfills, and rail yards are some examples.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.