Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
23 Solid and Hazardous Waste
© 2015 John Wiley & Sons, Inc. All rights reserved.
Overview of Chapter 23
Solid Waste
Waste Prevention
Reducing the Amount of Waste
Reusing Products
Recycling Materials
Hazardous Waste
Types of Hazardous Waste
Management of Hazardous Waste
© 2015 John Wiley & Sons, Inc. All rights reserved.
Waste electronics
Computers replaced every ~18-24 months
Perceived and often obsolete soon
E-waste – electronic waste of high quality plastics
and metals that comprise computers (and phones)
U.S. – 30kg per person annually
Business of recycling e-waste
Selling recyclable electronic
products
Ship most e-waste overseas
(disassembly can increase
exposure to hazards)
© 2015 John Wiley & Sons, Inc. All rights reserved.
Solid Waste
U.S. generates more solid waste per capita
than any other country
1.99kg (4.38lb) per person per day
251 million tons in 2012 (increase from 2010)
Waste generation is highest in developed
countries
Instead of repairing items, they are replaced
© 2015 John Wiley & Sons, Inc. All rights reserved.
Types of Solid Waste
Municipal solid waste
Solid material discarded by homes, office
buildings, retail stores, schools, etc.
Relatively small portion of solid waste produced
Non-municipal solid waste
Solid waste generated by industry, agriculture,
and mining
© 2015 John Wiley & Sons, Inc. All rights reserved.
Composition of Municipal Solid
Waste
© 2015 John Wiley & Sons, Inc. All rights reserved.
Disposal of Solid Waste
Three methods
Sanitary Landfills
Replaced open
dumps
Incineration
Recycling
© 2015 John Wiley & Sons, Inc. All rights reserved.
Sanitary Landfill
Compacting and burying waste under a
shallow layer of soil
Most common method of disposal
Problems
Methane gas production by microorganisms
Contamination of surface water & ground water
by leachate
Not a long-term remedy
Few new facilities being opened
Closing a full landfill is very expensive
© 2015 John Wiley & Sons, Inc. All rights reserved.
Sanitary Landfill
© 2015 John Wiley & Sons, Inc. All rights reserved.
Sanitary Landfill
Special Problem: Plastic
Much of plastic waste is from packaging
Chemically stable and do not readily break down and
decompose
Photo and
biodegradable plastics
Special Problem: Tires
Made from materials
that cannot be recycled
Can be incinerated or
shredded
© 2015 John Wiley & Sons, Inc. All rights reserved.
Incineration
Volume of solid waste reduced by 90%
Produces heat that can make steam to
generate electricity
Produce less carbon emissions than fossil fuel
power plants
Byproduct
Bottom ash
Fly ash
© 2015 John Wiley & Sons, Inc. All rights reserved.
Incineration - Types of
Incinerators
Mass burn (below), Modular, Refuse-derived
Mass burn, waste to energy
incinerator
© 2015 John Wiley & Sons, Inc. All rights reserved.
Incineration - Problems
Production of hazardous air pollutants
Carbon monoxide, particulates, heavy metals
Reduced by
Lime Scrubbers
Electrostatic Precipitators
Byproduct - Bottom ash (slag) and Fly ash
Must be disposed of in hazardous waste landfills
© 2015 John Wiley & Sons, Inc. All rights reserved.
Composting
Municipal Solid Waste Composting
Includes: Food scraps, Sewage sludge,
Agricultural manure, Yard waste
Reduces yard waste in landfills
Can be sold or
distributed to
community
Concern over heavy
metals
© 2015 John Wiley & Sons, Inc. All rights reserved.
Waste Prevention
Three Goals
1. Reduce the amount of waste
2. Reuse products
3. Recycle materials
© 2015 John Wiley & Sons, Inc. All rights reserved.
Reducing Waste
Purchase products with less packaging
© 2015 John Wiley & Sons, Inc. All rights reserved.
Reducing Waste
Source reduction
Products designed and manufactured to decrease
the volume of solid waste
Reuse and recycle wastes at the plant where they
are generated
35% weight reduction in aluminum cans since
1970s
Pollution Prevention Act (1990)
Dematerialization
Progressive decrease in the size and weight of a
product as a result of technological improvements
© 2015 John Wiley & Sons, Inc. All rights reserved.
Reusing Products
Refilling glass beverage bottles used to be
standard
Heavier glass required in reusable glass bottles-
costs more to make and transport
Cheaper to use lightweight, non-reusable glass
Japan recycles almost all bottles
Reused 20 times
11 U.S. States have deposits on cans and
bottles to promote reuse
© 2015 John Wiley & Sons, Inc. All rights reserved.
Recycling Materials
Every ton of recycled paper saves:
17 trees
7000 gallons of water
4100 kwatt-hrs of energy
3 cubic yards of landfill space
Recycle
Glass bottles, newspapers, steel cans, plastic
bottles, cardboard, office paper
© 2015 John Wiley & Sons, Inc. All rights reserved.
Recycling
U.S. recycles 38% of
Municipal Solid Waste
Recycling Paper
U.S. recycles 62.1%
Increased due to
consumer demand for
recycled paper products
Recycling Glass
U.S. recycles 25%
Costs producers less
than new glass (right)
© 2015 John Wiley & Sons, Inc. All rights reserved.
Recycling
Recycling Aluminum
Making new can from recycled one costs far less
than making a brand new one (economic
incentive)
55% of aluminum was recycled in 2012
Recycling Metals other than Aluminum
Metal recycling influenced by economy
Lead, gold, iron, steel, silver and zinc
Metallic composition is often unknown
Makes recycling difficult
© 2015 John Wiley & Sons, Inc. All rights reserved.
Recycling
Recycling Plastic
14% of all plastic is
recycled (2012)
May be less expensive to
make from raw materials
31% of PET in water and
soda bottles is recycled
Most plastic containers are
made of many types of
plastic that must be
separated to be recycled
© 2015 John Wiley & Sons, Inc. All rights reserved.
Recycling
Recycling Tires
45% recycled in 2012
Few products are made from old tires
Playground equipment
Trashcans
Garden hose
Carpet
Roofing materials
© 2015 John Wiley & Sons, Inc. All rights reserved.
Integrated Waste Management
© 2015 John Wiley & Sons, Inc. All rights reserved.
Hazardous Waste
Any discarded chemical
that threatens human
health or the environment
Reactive, corrosive,
explosive or toxic chemicals
1% of waste stream in U.S.
Love Canal (1977)
Classic case of hazardous
waste contaminating human
and environmental health Love Canal Toxic Waste Site
© 2015 John Wiley & Sons, Inc. All rights reserved.
Hazardous Waste
© 2015 John Wiley & Sons, Inc. All rights reserved.
Hazardous Waste
Dioxin
Formed as byproduct of combustion of chlorine
compounds (medical waste incineration and others)
Bioaccumulates and biomagnifies through food web
Causes cancer, effect reproductive, immune and
nervous system
Polychlorinated Biphenyls (PCBs)
Used as cooling fluid, fire retardant, lubricator
Disposed of in open dumps, sewers and fields in 1970s - issue
in groundwater today
Endocrine disrupter
© 2015 John Wiley & Sons, Inc. All rights reserved.
Case-In-Point Hanford Nuclear
Reservation
© 2015 John Wiley & Sons, Inc. All rights reserved.
Management of Hazardous Waste
Chemical accidents
National Response Center notified
Typically involves oil, gasoline or other petroleum
spill
Current Management Policies
Resource Conservation and Recovery Act (1976,
1984)
Comprehensive Environmental Response,
Compensation, and Liability Act (1980)
Commonly known as Superfund
© 2015 John Wiley & Sons, Inc. All rights reserved.
Superfund Program
Pesticides dumps
Piles of mining wastes
>10,000 hazardous
sites qualify
Cleaning up existing hazardous waste:
400,000 waste sites
Leaking chemical storage tanks and drums
(below)
© 2015 John Wiley & Sons, Inc. All rights reserved.
Management of Hazardous Waste
Superfund National Priorities List
2014: 1,326 sites on the list
States with the greatest number of sites
New Jersey (114)
California (97)
Pennsylvania (95)
New York (86)
Michigan (65)
© 2015 John Wiley & Sons, Inc. All rights reserved.
Management of Hazardous Waste
Biological Treatment of Hazardous Chemicals
Bioremediation - use of bacteria and other
microorganisms to break down hazardous waste
into relatively harmless products
1000 species of bacteria and fungi
Time consuming
Inexpensive
Phytoremediation- use of plants to absorb and
accumulate hazardous materials in the soil
Phytoextraction
Ex: Indian mustard removes heavy metals
© 2015 John Wiley & Sons, Inc. All rights reserved.
Examples of Phytoremediation
© 2015 John Wiley & Sons, Inc. All rights reserved.
Management of Hazardous Waste
1) Source reduction
1) Most effective
2) Conversion to less hazardous materials
3) Long-term storage
© 2015 John Wiley & Sons, Inc. All rights reserved.
Hazardous Waste Landfill