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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 - PowerPoint PPT Presentation


Managing Solid Waste Disposal

SOLID, TOXIC & HAZARDOUSWASTEManaging Solid Waste DisposalWaste 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 dumpSome waste contain valuable resources reduce, reuse, recycleAmericans produce 4.5 pounds of solid waste per day76% ends up in landfills

WasteWaste = 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 SourcesGreatest source in US mining & agricultureMSW relatively small proportion of solid waste#1 paper#2 yard trimmings#3 food

WASTE DISPOSAL METHODSOpen dump unsanitary, dangerous, malodorous, vermin-infestedPoor often live on or nearSanitary landfillLined with layers of clay & plastic to decrease leachateLeachate collected & treated as wastewaterTrash alternately compacted & covered with soilPipes 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 tableLandfills have drawbacksExperts believe that leachate will eventually escapeThe liner will become puncturedLeachate collection systems eventually arent maintainedIt is hard to find places suitable for landfillsThe Not-In-My-Backyard (NIMBY) syndromeThe Garbage barge case In 1987, Islip, New Yorks landfills were full, and a barge traveled to empty the waste in North Carolina, which rejected the loadIt returned to Queens to incinerate the waste, after a 9,700 km (6,000 mile) journeyNYC 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 closureThousands of landfills lie abandonedManagers closed smaller landfills and made fewer larger landfillsIn 1988, the U.S. had nearly 8,000 landfills Today there are fewer than 1,700Growing cities converted closed landfills into public parksFlushing Meadows in Queens, New York, was redeveloped for the 1939 Worlds Fair

WASTE DISPOSAL METHODSToxic Colonialism send solid & hazardous waste to developing countriesUS 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 DumpingIllegal Ocean Dumping Ban Act of 1988Prohibits dumping sewage sludge, industrial waste, medical wastes, MSWGreat Pacific Garbage Patch

Great Pacific Garbage patch

Great Pacific Garbage Patch

WASTE DISPOSAL METHODSIncinerationa controlled process in which mixed garbage is burned at very high temperaturesReduces amount of landfill volume 80-90%Refuse Derived Fuel non-combustibles removedMass Burn Incinerators burn anything smaller that a refrigeratorMore cost effectiveReleases 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 electricityMore than 100 facilities are in use across the U.S.They can process nearly 100,000 tons of waste per dayBut, they take many years to become profitableCompanies contract with communities to guarantee a minimum amount of garbageLong-term commitments interfere with the communities later efforts to reduce wasteA typical solid waste incinerator

Improved disposal methods Most industrialized nations now bury waste in lined and covered landfills or burn it in incineration facilitiesIn the U.S., recycling is decreasing pressure on landfills

DIOXINSChlorinated hydrocarbonsMost toxic TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin)Naturally produced during forest firesAnthropogenic sources incinerators, smelters, chlorine bleaching at paper mills, tobacco smokeBioaccumulate & biomagnifyTeratogenic (birth defects), immunotoxic, carcinogen, liver damage, rashes, skin discolorationLove Canal, NY & A Civil Action

Reducing WasteReduce, Reuse, RecycleReduceDecrease packagingSource reduction (redesign to use less material)ReuseUse the waste for another or the same purposeReuse plastic grocery bagsReuse glass containers (glass bottle can be used 15 times)RecycleConvert to another productOpen loop recycling convert to a different productClosed-loop recycling recycled to same productRECYCLINGMust be profitableReduces air pollutionStepsCollection and processing of materialsMaterials Recovery Facilities (MRFs)-items sorted, cleaned & preparedUse recyclables to make new productsConsumers purchase goods from recycled materials

Paper RecyclingPaper making process energy & water intensive, also uses chlorine makes sense to recycleOpen-loop recycling1st de-inkMix with fresh pulp (fibers shorten each time recycled)Uses less chlorine & waterReduces air pollutionFewer trees harvested

CompostingDiverts food and yard waste from the waste streamConverting organic waste into mulch or humus through natural biological process of decompositionEnriches soil, reduces erosionHome compostingMunicipal compostingEstablished area in which yard wastes & tree trimmings converted to mulch (a green fertilizer)Recycling has grown rapidly and can expandThe EPA calls the growth of recycling one of the best environmental success stories of the late 20th centuryRecycling rates vary widely, depending on the product 67% of major appliances are recycledOnly 6% of plastics are recycled

Recycling rates vary widely in the U.S.

Recycling DifficultiesPlastic difficult to recycle Soda bottles (PET plastics) recycled into carpets, clothing, bottles & packagingContamination with PVC plastic can render PET unusable for recyclingRecycled plastic more expensiveBiodegradable plastics only partially biodegradablePhotodegradable (in a landfill???)TiresCan be reused (not recycled vulcanized rubber cannot be remelted)Difficult to buryShredded to use in playgrounds & as artificial mulchIncinerated for energyRecycling DifficultiesLead & Lead ToxicityRecycled from automobile batteriesBioaccumulates in boneLeads to mental retardation, lowered IQs, hyperactivity, ADHD, learning disordersMax level 10g/dL of bloodDemanufacturing Taking apart household items & retrieve recyclable componentsRefrigerators, stoves, televisions, air conditionersComputers, electronics, etc

Hazardous WastesAny wastes that are flammable, explosive, corrosive or highly reactiveChemicals that are toxic, carcinogenic, mutagenic, teratogenicNot radioactive wastesMost is recycled, stored or converted to less hazardous materialHazardous WasteHazardous 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 fumesToxic = substances that harm human health when they are inhaled, are ingested, or contact human skinHazardous wastes have diverse sourcesIndustry = produces the largest amount of hazardous wasteBut waste generation and disposal is highly regulatedMiningHouseholds = now the largest producer of unregulated hazardous wastePaints, batteries, oils, solvents, cleaning agents, pesticidesSmall businessesAgricultureUtilitiesBuilding demolition

Organic compounds can be hazardousParticularly hazardous because their toxicity persists over time Synthetic organic compounds = resist decompositionKeep buildings from decaying, kill pests, and keep stored goods intact Their resistance to decay causes them to be persistent pollutantsThey are toxic because they are readily absorbed through the skinThey can act as mutagens, carcinogens, teratogens, and endocrine disruptorsHeavy metals can be hazardousLead, chromium, mercury, arsenic, cadmium, tin, and copper Used widely in industry for wiring, electronics, metal plating, pigments, and dyesThey enter the environment when they are disposed of improperlyHeavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnifyPCBsPolychlorinated 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 incinerationE-waste is a new and growing problemElectronic waste (e-waste) = waste involving electronic devices Computers, printers, VCRs, fax machines, cell phones Disposed of in landfills, but should be treated as hazardous wasteSome people and businesses are trying to use and reuse electronics to reduce waste

Managing Hazardous WastesEasiest way to control avoid usingGreen chemistry redesigning chemical processes to be less hazardousPhysical processesusing charcoal to absorb toxinsDistillingIncineration (PCBs) but can release dioxinsLong term storage in secure landfillsBioremediation using bacteria or other microbes to break down Natural or genetically engineered (PCBs, organic solvents, pesticides)Managing Hazardous WastesPhytoremediation using plants (possibly genetically engineered) to absorb &amp