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Lecture 8.2: Disposing of MSW . Chapter 16. You need to dispose of all the wastes generated by all the dormitories and dining hall somewhere on Tabor’s campus. BRAINSTORM at least three different possibilities. Where Does MSW G o?. Open dumps: the Meadowlands, NJ Landfills
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Lecture 8.2: Disposing of MSW Chapter 16
You need to dispose of all the wastes generated by all the dormitories and dining hall somewhere on Tabor’s campus. • BRAINSTORM at least three different possibilities.
Where Does MSW Go? • Open dumps: the Meadowlands, NJ • Landfills • Incineration
Choosing a Location (Siting) a Landfill • Controversial • Political • Soils with clay • Away from water sources • Proximate yet distant from populus centers • NIMBY • Environmental justice
Leachate • Garbage Juices • “Sanitary Landfill”: clay/plastic liners • Pipes to collect leachate • Anaerobic conditions methane • Closing a Landfill=“Cap”
Landfill Inputs • Control leachables & methane production • Paper/plastic • Al/Cu recyclable • Glass/plastic: inert • Metals(eWaste)leach • Food scraps/yard wastes methane
Reaching Capacity • “close” the landfill • Cap the landfill • Vent the landfill • Reclaim the landfill
Problems With Landfills • siting • leachate contamination • adjacent waterways • human toxicity • methane gas release greenhouse gas • Dr. Rathje’s study on decomposition rates of landfills • Benefit: collect methane and use it for energy
Groundwater monitoring well Groundwater Leachate monitoring well Leachate pumped up to storage tanks for safe disposal Leachate pipes When landfill is full, layers of soil and clay seal in trash Groundwater monitoring well Groundwater Leachate pumped up to storage tanks for safe disposal Leachate pipes Leachate monitoring well Electricity generator building Methane storage and compressor building Topsoil Leachate treatment system Sand Clay Garbage Pipe collect explosive methane gas used as fuel to generate electricity Methane gas recovery Leachate storage tanks Compacted solid waste Garbage Sand Synthetic liner Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill Sand Clay Subsoil Sanitary Landfill
Special Problem of Tires • Cannot be melted and reused for tires • Made from materials that cannot be recycled • Can be incinerated or shredded
Incineration • Volume of solid waste reduced by 90% • Produces heat that can make steam to generate electricity
Incineration • Siteselection often controversial • unsightly, truck traffic, EXPLOSIONS • (toxic) ash disposal • siting: NIMBY • Air pollution • Hg/Dioxins • Discourages recycling Ash: fly ash –v- bottom ash Tipping fees ($70/ton)
MSW Disposal • Source reduction by individual citizens • Landfills • Incineration • What about “toxic” wastes?-tommorow