Download - SOLID, TOXIC & HAZARDOUS WASTE
SOLID, TOXIC & HAZARDOUS
WASTE
Managing Solid Waste Disposal
Waste Stream – the steady flow of matter from raw materials, through manufacturing, product formation and marketing, and on to its final resting place – a solid waste dump Some waste contain valuable resources – reduce,
reuse, recycle Americans produce 4.5 pounds of solid waste per day 76% ends up in landfills
Waste
Waste = any unwanted material or substance that results from human activity or process
Municipal solid waste (MSW) = non-liquid waste that comes from homes, institutions, and small businesses
Industrial solid waste (ISW) = waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining
Hazardous waste =solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive
Wastewater = water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains
Sources
Greatest source in US – mining & agricultureMSW relatively small proportion of solid
waste#1 paper#2 yard trimmings#3 food
WASTE DISPOSAL METHODS
Open dump – unsanitary, dangerous, malodorous, vermin-infested Poor often live on or near
Sanitary landfill Lined with layers of clay & plastic to decrease
leachate Leachate collected & treated as wastewater Trash alternately compacted & covered with soil Pipes collect methane (source of energy of burned off) Site selection important (geologically, proximity to
source)
Sanitary Landfill
To protect against environmental contamination, landfills must be located away from wetlands, earthquake-prone faults, and 20 ft above water table
Landfills have drawbacks
Experts believe that leachate will eventually escape The liner will become punctured Leachate collection systems eventually aren’t
maintainedIt is hard to find places suitable for landfills
The Not-In-My-Backyard (NIMBY) syndromeThe “Garbage barge” case
In 1987, Islip, New York’s landfills were full, and a barge traveled to empty the waste in North Carolina, which rejected the load
It returned to Queens to incinerate the waste, after a 9,700 km (6,000 mile) journey
NYC Garbage BargeThe garbage was finally burned in New
York, and the 430 tons of ash sent to Islip to be buried.
Landfills can be transformed after closure
Thousands of landfills lie abandoned Managers closed smaller landfills
and made fewer larger landfillsIn 1988, the U.S. had nearly 8,000
landfills Today there are fewer than 1,700
Growing cities converted closed landfills into public parks Flushing Meadows in Queens, New
York, was redeveloped for the 1939 World’s Fair
WASTE DISPOSAL METHODS
Toxic Colonialism – send solid & hazardous waste to developing countries US exports 80% of its e-waste to Asia (contain heavy
or toxic metals) Poor neighborhoods & Native American reservations
(no resources to fight waste disposal)Ocean Dumping
Illegal Ocean Dumping Ban Act of 1988
Prohibits dumping sewage sludge, industrial waste, medical wastes, MSW
Great Pacific Garbage Patch
Great Pacific Garbage Patch
WASTE DISPOSAL METHODS
Incineration a controlled process in which mixed garbage is
burned at very high temperatures Reduces amount of landfill volume 80-90% Refuse Derived Fuel – non-combustibles removed Mass Burn Incinerators – burn anything smaller that a
refrigerator More cost effective
Releases air pollutants & require post-combustion controls
Many incinerators create energyIncineration is used to reduce the volume of
waste and generate electricity Waste-to-energy facilities (WTE) = use
the heat produced by waste combustion to create electricity More than 100 facilities are in use across the U.S. They can process nearly 100,000 tons of waste per
day But, they take many years to become profitable
Companies contract with communities to guarantee a minimum amount of garbage Long-term commitments interfere with the
communities’ later efforts to reduce waste
A typical solid waste incinerator
Improved disposal methods
Most industrialized nations now bury waste in lined and covered landfills or burn it in incineration facilities In the U.S., recycling is decreasing pressure on landfills
DIOXINS
Chlorinated hydrocarbons Most toxic TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) Naturally produced during forest fires Anthropogenic sources – incinerators, smelters,
chlorine bleaching at paper mills, tobacco smoke Bioaccumulate & biomagnify Teratogenic (birth defects), immunotoxic, carcinogen,
liver damage, rashes, skin discoloration Love Canal, NY & “A Civil Action”
Reducing Waste
Reduce, Reuse, RecycleReduce
Decrease packaging Source reduction (redesign to use less material)
Reuse Use the waste for another or the same purpose
Reuse plastic grocery bags Reuse glass containers (glass bottle can be used 15 times)
Recycle Convert to another product
Open loop recycling – convert to a different product Closed-loop recycling – recycled to same product
RECYCLING
Must be profitableReduces air pollutionSteps
1. Collection and processing of materials Materials Recovery Facilities (MRFs)-items sorted,
cleaned & prepared2. Use recyclables to make new products3. Consumers purchase goods from recycled materials
Paper Recycling
Paper making process energy & water intensive, also uses chlorine – makes sense to recycle
Open-loop recycling 1st – de-ink Mix with fresh pulp (fibers shorten each time
recycled) Uses less chlorine & water Reduces air pollution Fewer trees harvested
Composting
Diverts food and yard waste from the waste stream
Converting organic waste into mulch or humus through natural biological process of decomposition Enriches soil, reduces erosion
Home compostingMunicipal composting
Established area in which yard wastes & tree trimmings converted to mulch (a green fertilizer)
Recycling has grown rapidly and can expand
The EPA calls the growth of recycling “one of the best environmental success stories of the late 20th century”
Recycling rates vary widely, depending on the product 67% of major appliances
are recycled Only 6% of plastics are
recycled
Recycling rates vary widely in the U.S.
Recycling Difficulties
Plastic difficult to recycle Soda bottles (PET plastics) recycled into carpets, clothing,
bottles & packaging Contamination with PVC plastic can render PET unusable for
recycling Recycled plastic more expensive Biodegradable plastics only partially biodegradable Photodegradable (in a landfill???)
Tires Can be reused (not recycled – vulcanized rubber cannot be
remelted) Difficult to bury Shredded to use in playgrounds & as artificial mulch Incinerated for energy
Recycling Difficulties
Lead & Lead Toxicity Recycled from automobile batteries Bioaccumulates in bone Leads to mental retardation, lowered IQs,
hyperactivity, ADHD, learning disorders Max level 10µg/dL of blood
Demanufacturing
Taking apart household items & retrieve recyclable components Refrigerators, stoves, televisions, air conditioners Computers, electronics, etc
Hazardous Wastes
Any wastes that are flammable, explosive, corrosive or highly reactive
Chemicals that are toxic, carcinogenic, mutagenic, teratogenic
Not radioactive wastesMost is recycled, stored or converted to less
hazardous material
Hazardous Waste
Hazardous waste is defined as:Ignitable = substances that easily catch fire
(natural gas, alcohol)Corrosive = substances that corrode metals in
storage tanks or equipmentReactive = substances that are chemically
unstable and readily react with other compounds, often explosively or by producing noxious fumes
Toxic = substances that harm human health when they are inhaled, are ingested, or contact human skin
Hazardous wastes have diverse sources
Industry = produces the largest amount of hazardous waste But waste generation and disposal is highly regulated
MiningHouseholds = now the largest producer of unregulated
hazardous waste Paints, batteries, oils, solvents, cleaning agents,
pesticidesSmall businessesAgricultureUtilitiesBuilding demolition
Organic compounds can be hazardous
Particularly hazardous because their toxicity persists over time Synthetic organic compounds = resist decomposition
Keep buildings from decaying, kill pests, and keep stored goods intact
Their resistance to decay causes them to be persistent pollutants
They are toxic because they are readily absorbed through the skin
They can act as mutagens, carcinogens, teratogens, and endocrine disruptors
Heavy metals can be hazardous
Lead, chromium, mercury, arsenic, cadmium, tin, and copper
Used widely in industry for wiring, electronics, metal plating, pigments, and dyes
They enter the environment when they are disposed of improperly
Heavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify
PCBs
Polychlorinated biphenyls – chlorinated hydrocarbonsPersistent and bioaccumulate & biomagnifyMade in US until 1976Used in electric transformers, capacitors, pumps &
turbinesUsed as adhesive, lubricants, fire retardants,
hydraulic fluidsAcute exposure - causes nausea, diarrhea, vomitingChronic – interferes with endocrine systemRemoved by bioremediation or incineration
“E-waste” is a new and growing problem
Electronic waste (“e-waste”) = waste involving electronic devices Computers, printers, VCRs,
fax machines, cell phones Disposed of in landfills, but
should be treated as hazardous waste
Some people and businesses are trying to use and reuse electronics to reduce waste
Managing Hazardous Wastes
Easiest way to control – avoid usingGreen chemistry –redesigning chemical
processes to be less hazardous Physical processes
using charcoal to absorb toxins Distilling Incineration (PCBs) – but can release dioxins Long term storage in secure landfills
Bioremediation –using bacteria or other microbes to break down Natural or genetically engineered (PCBs, organic
solvents, pesticides)
Managing Hazardous Wastes
Phytoremediation – using plants (possibly genetically engineered) to absorb & accumulate toxic materials from the soil Sunflowers remove lead Poplar trees remove many contaminants Canola removes selenium
Plants become contaminated & must be disposed of properly
Slow processOnly works to depth of roots
Hazardous Waste Disposal
For many years, hazardous waste was discarded without special treatment Public did not know it was harmful
to human health Assumed the substances would
disappear or be diluted in the environment
Since the 1980s, cities designate sites or special collection days to gather household hazardous waste
Hazardous Waste Disposal
Resource Conservation and Recovery Act (RCRA, 1976) Main legislation that controls
hazardous waste disposal States are required to manage
hazardous waste Intended to ensure testing and
ensure correct disposal methods (prevent illegal dumping)
Large generators of hazardous waste must obtain permits and must be tracked “from cradle to grave”
Love Canal NY 1978NIAGARA FALLS, N.Y.--Twenty five years after the Hooker Chemical Company stopped using the Love Canal here as an industrial dump, 82 different compounds, 11 of them suspected carcinogens, have been percolating upward through the soil, their drum containers rotting and leaching their contents into the backyards and basements of 100 homes and a public school built on the banks of the canal.
Love Canal, NY
The first declared national environmental disasterEntire community evacuatedChemical hazardous wastes stored in the canal for
decadesDump closed & house built Tanks began leaking, children developed chemical
burnsMiscarriages & birth defectsYears of litigation – company required to clean up
siteImpetus for passing Superfund Act (CERCLA)
CERCLA & SARA
Comprehensive Emergency Response, Compensation and Liability Act (CERCLA, Superfund Act, 1980)
Amended in 1984 – Superfund Amendments and Reauthorization Act (SARA) Intended to allow the feds to respond quickly to
hazardous waste contamination Established a federal program to clean up U.S. sites
polluted with hazardous waste Experts identify polluted sites, take action to protect
groundwater near these sites, and clean up the pollution
CERCLA & SARA
EPA administers the act & determines which sites require attention Supertoxic, carcinogenic, mutagenic, teratogenic Chemicals of greatest concern
Lead Trichloroethylene Toluene Benzene PCBs Chloroforms Phenol Arsenic Cadmium Chromium
Superfund: harmful sites
Harmful sites are: Placed on the EPA’s National Priority List Ranked according to the level of risk to human health
that they pose Cleaned up on a site-by-site basis as funds are
availableThe EPA is required to hold public hearings
and inform area residents of its findings and to receive feedback
CERCLA & SARA
Sites placed on the National Priorities List Currently 1,162 sites (113 in NJ) as of 1/24/14
Include abandoned factories, smelters, mills, refineries & chemical plants
If unable to determine who is responsible for damage, cleanup is paid for from Superfund Money generated by taxing chemical & hazardous
materials Tax expired in 1995 and has not been reauthorized Currently funds come from taxpayers Companies required to file annual Toxic Release
Inventory
Contaminated sites are being slowly cleaned up
Globally, thousands of former military and industrial sites are contaminated with hazardous waste For most nations, dealing with these messes is
too difficult, time consuming and expensive
The Superfund process
Once a Superfund site is identified, EPA scientists evaluate: How close the site is to human habitation Whether wastes are currently confined or likely to
spread Whether the site threatens drinking water supplies
Upper Ringwood Superfund Site
The Superfund Act
Superfund
Later laws charged the EPA with cleaning up brownfields = lands whose reuse or development are complicated by the presence of hazardous materials
Two events spurred creation of Superfund legislation In Love Canal, Niagara Falls, New York, families were
evacuated after buried toxic chemicals rose to the surface, contaminating homes and an elementary school
In Times Beach, Missouri, the entire town was evacuated after being contaminated with dioxin from waste oil sprayed on roads
Brownfields
Site contaminated with toxic or hazardous materials
Abandoned properties with not enough contamination to be on National Priorities List
Many industrial areas in urban areas
Subject to remediation so they may be reclaimed and used by humans
Illegal dumping of hazardous waste
Since hazardous waste disposal is costly, it results in illegal and anonymous dumping by companies, Creating health risks Industrial nations illegally dump in developing nations Basel Convention, an international treaty, should
prevent dumping but it still happensHigh costs of disposal encourages companies
to invest in reducing their hazardous waste
Three disposal methods for hazardous waste
These methods do nothing to lessen the hazards of the substances But they help keep the substance isolated from people,
wildlife, and ecosystemsLandfills = must have several impervious liners
and leachate removal systems Design and construction standards are stricter than for
ordinary sanitary landfills Must be located far from aquifers
Surface impoundments
Surface impoundments = store liquid hazardous waste
Shallow depressions are lined with plastic and clay
Water containing waste evaporates, the residue of solid hazardous waste is then transported elsewhere
The underlying clay layer can crack and leak waste, and rainstorms cause overflow, contaminating nearby areas
Deep-well injection
Deep-well injection = a well is drilled deep beneath the water table and waste is injected into it A long-term disposal method The well is intended to be
isolated from groundwater and human contact
However, the wells become corroded and leak waste into soil
Radioactive waste is especially hazardous
Radioactive waste is particularly dangerous and persistent
Yucca Mountain in Nevada is now designated as the single-site repository for all U.S. nuclear waste
The Waste Isolation Pilot Plant (WIPP) is the world’s first underground repository for transuranic waste from nuclear weapons development Caverns holding the waste are 655 m (2,150 ft)
below ground in a huge salt formation thought to be geologically stable
WIPP became operational in 1999 and is receiving thousands of shipments of waste
Yucca Mountain, Nevada