WASTE DISPOSAL METHODSHTET LINN KHANT

Not toxicHandled on siteNot toxicAreas of concern

Paper: 50%

Municipal WasteOpen DumpSanitary LandfillIncinerationOcean dumping

Open Dump

Unsanitary, draws pests and vermin, harmful runoff and leachates, toxic gasesStill accounts for half of solid waste Several thousand open dumps in the USA

Sanitary LandfillSanitary LandfillLayer of compacted trash covered with a layer of earth once a day and a thicker layer when the site is fullRequire impermeable barriers to stop escape of leachates: can cause problem by overflowGases produced by decomposing garbage needs venting 1 acre/10,000 people: acute space problem: wastes piling up over 150 million tons/year; # of landfills down from 8000(1988) to 3091(1996)NIMBY, NIMFYE, NIMEY, NOPENJ ships >5 million tons of waste every year

IncinerationSolves space problem but:produces toxic gases like Cl, HCl, HCN, SO2High temp furnaces break down hazardous compounds but are expensive ($75 - $2K/ton)Heat generated can be recovered: % of waste burntJapan 67%, Switzerland 80%, USA 6%North Little Rock, AK saving $50K in heating cost and reducing landfill requirement by 95%How many MSW combustors exist in the United States? In 1996, 110 combustors with energy recovery existed with the capacity to burn up to 100,000 tons of MSW per day.

Ocean DumpingOut of sight, free of emission control normsContributes to ocean pollutionCan wash back on beaches, and can cause death of marine mammals Preferred method: incineration in open seaOcean Dumping Ban Act, 1988: bans dumping of sewage sludge and industrial wasteDredge spoils still dumped in oceans, can cause habitat destruction and export of fluvial pollutants

Reducing WasteIncineration, compactingHog feed: requires heat treatmentComposting: requires separation of organics from glass and metalsRecycling and ReusingRecycle of glass containers: 5 million tonsPlastic: marked by types for easy recyclingConverted into Fibers, trash bags, plastic lumber, fill for pillows, insulation etcJunked cars: 150 200 kg of plastics: soon to be recycled

Waste ExchangeOne persons waste can be another persons raw materialFluorite from Al smelter in MD Isopropyl alcohol = cleaning solventNitric Acid from Electronic Industry = high grade fertilizerSpent acid of steel industry = control for H2S

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