Waste

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					Waste Disposal


   Chapter 15
Some Facts
   In 1996, U.S. residents, businesses, and
    institutions produced more than 209 million
    tons of MSW, which is approximately 4.3 pounds
    of waste per person per day, up from 2.7 pounds
    per person per day in 1960 = mass of Statue of
    Liberty every 5 years
   United States
       has 8% of world population
       Consume 1/3rd of World’s resources
       Produces ½ of World’s garbage
    Handled on site
                          Not toxic




                      Not toxic



Areas of concern
1991 data


            Paper: 50%
Municipal Waste
   Open Dump
   Sanitary Landfill
   Incineration
   Ocean dumping
Open Dump

   Unsanitary, draws pests and vermin,
    harmful runoff and leachates, toxic gases
   Still accounts for half of solid waste
   Several thousand open dumps in the USA
     Sanitary Landfill
   Sanitary Landfill
       Layer of compacted trash covered with a layer of earth
        once a day and a thicker layer when the site is full
       Require impermeable barriers to stop escape of
        leachates: can cause problem by overflow
       Gases 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, NOPE
       NJ ships >5 million tons of waste every year
    Incineration
   Solves space problem but:
       produces toxic gases like Cl, HCl, HCN, SO2
       High temp furnaces break down hazardous compounds but
        are expensive ($75 - $2K/ton)
       Heat generated can be recovered: % of waste burnt
           Japan 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 Dumping
   Out of sight, free of emission control norms
   Contributes to ocean pollution
   Can wash back on beaches, and can cause death of
    marine mammals
   Preferred method: incineration in open sea
   Ocean Dumping Ban Act, 1988: bans dumping of
    sewage sludge and industrial waste
   Dredge spoils still dumped in oceans, can cause
    habitat destruction and export of fluvial pollutants
    Reducing Waste
   Incineration, compacting
   Hog feed: requires heat treatment
   Composting: requires separation of organics from
    glass and metals
   Recycling and Reusing
        Recycle of glass containers: 5 million tons
        Plastic: marked by types for easy recycling
        Converted into Fibers, trash bags, plastic lumber, fill for
         pillows, insulation etc
        Junked cars: 150 – 200 kg of plastics: soon to be recycled
•In 1996, recycling of solid waste
in the United States prevented the
release of 33 million tons of
carbon into the air—roughly the
amount emitted annually by 25
million cars.


•1 ton of newspaper=18 trees, 3
m3 of landfill, 60% less energy.
Govt recycling saving 223,000
tons, 4 million trees, $7.4 million



                                      Auto Steel     Aluminum    Paper & Yard      Glass     Plastic   Tires
                                      Batteries Cans Packaging    Paperboard waste container container
    Waste Exchange
   One persons waste can be another persons
    raw material
   Fluorite from Al smelter in MD
   Isopropyl alcohol = cleaning solvent
   Nitric Acid from Electronic Industry = high
    grade fertilizer
   Spent acid of steel industry = control for H2S
    Liquid Waste
   Sewage
   Highly toxic Industrial Waste & Used Oil
       Dilute and Disperse
       Concentrate and Contain
       Secure Landfill
           Sealed drums to be put in impermeable holds with monitoring
            wells to check for leakage: does not work
       Deep well Disposal
           Pumping in deep porous layer bounded by impermeable
            formations, well below water table
           $1 million to drill, $15-20/ton afterwards
           Restricted by geological considerations, can trigger
            earthquakes
    Story of Love Canal
   A ditch 20m wide, 3m deep and 1km long
   1890: Built near Niagara falls for hydro-power
   1905: Hooker Electrochemical established
   1942: Hooker buys the site for waste disposal, 20,000 tons of toxic
    chemical dumped in 10 yr
   1953: site bought by Niagara School board for $1, Hooker absolved of any
    future damage
   1977: study shows toxic effects in adjoining homes,>40 toxic chemicals
    identified
   1978: Health advisory, 100 families to be shifted
   1980: remedial measures taken, EPA study shows chromosome defects in
    residents, President Carter declares emergency, provides federal aid
   1981: Over 500 families moved out, hundreds waiting for aid
   EPA estimate: 30,000 hazardous waste sites in US, only 10% of hazardous
    wastes properly disposed, 300 million tons generated each year
    Sewage Treatment
   Individual scale
       Settling tank (solids settle and are broken down)
       Leaching field: receives liquids from septic tank
        through porous pipes. Bacteria and oxygen breaks
        down organics and disease causing germs
       Should have soil layer = 60 cm below 150cm
        above
       Should not be within 15m of any water body
       0.5 to 1 acre per dwelling
Municipal Sewage Treatment
   75% of US population served by sewage system
    and <5% releases untreated sewage
   Primary treatment: removal of solids
   Secondary treatment: biological
       Bacteria and fungi breaks down organics
       Chlorinated to kill germs, can form chloroform
        which is carcinogenic
   Tertiary treatment: Filtration and chemical
    treatment: expensive
   Sludge is a by-product and is rich in organics and
    nutrients
     Radioactive Waste Disposal
   Isotopes with short half-lives are gone quickly, those
    with long half-lives will decay too little
   Low level wastes: 90% of all radioactive wastes
       20 temporary and 6 commercial disposal sites
       States to take care of their low level waste
   High level wastes e.g., spent nuclear fuel rods
       Should be so disposed as to cause less than 1000 death in
        10,000 years
High Level Waste Depository
   Rocketing to sun
   Under Antarctica Ice sheet
   Subduction Zone
   Sea bed disposal
   Bedrock caverns
       Granites, basalt, tuff, shale, salt caverns
       Salt: High melting point, impermeable in dry
        condition, self-sealing, cheap resource
   No permanent high level waste repository yet
Requirements for a radio-active
waste disposal system
   Design and Fabricate a System that will
       Last thousands of years longer than recorded
        human history
       Be robust enough to isolate highly radioactive
        material so that it will not threaten human
        health and environment for more than ten
        thousand years.
Story of Yucca Mountain Site
   1982: Nuclear Waste Policy Act
       Congress charges DOE with the task
       Two high level waste depository in the eastern and
        the western USA
       Billions collected from tax on utilities
   1986: Hanford, Wa, Yucca Mtn, Ne and Deaf
    Smith County, Tx shortlisted as western sites
   1987: Congress suddenly decides on Nevada
    (screw Nevada bill)
       Nevada to receive $20 million/year
   Feb 15, 2002: Pres. Bush approved Yucca Mtn as
    the site for high level nuclear waste respository
Yucca Mountain Site
   Geologically stable (?)
       Limited fault displacement
       No volcanism in 10,000 years
   Tuff host rock, 1000 ft below the surface, 1000 ft
    above the water table
   Arid climate, no streams, low water table
   Low population density
   Federally owned land, close to Nevada test sites

				
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posted:12/4/2011
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