Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
APES - Monday Ch. Questions 28, 24 to be checked Review Ch. 24 Test Ch. 18, 24 Tuesday Make up test Wednesday Labs Due Wednesday (Radish, Biofuel) Chemical Poster presentations Wed. – Coffee House style & Finish Toxic Lab
Ch. 24 Solid and Hazardous Waste 1942-1953 “Hooker Chemicals and Plastics” Sealed chemical wastes into steel drums, dumped them into an old canal excavation Niagara Falls, NY Children - diseases and burns from playgrounds Superfund Law – created by Jimmy Carter (CERCLA) Love Canal: There is No Away Figure 24-1Page 532
Superfund Legislation • Comprehensive Environmental Response, Compensation, and Liabilities Act (CERCLA); 1980 • “Superfund” to clean up abandoned sites
a solution to previously contaminated sites w/no-one to pay • 2 levels • Emergency response • immediate threat to human health or environment • Long term remediation • if Hazard Ranking System (HRS) shows a score over 27.5, it is added to the National Priorities List (NPL) for Superfund cleanup • 1300 sites on NPL in 1990, more to come
Resource Conservation and Recovery Act (RCRA) - Congress in 1976 protect human health & environment From potential hazardous waste disposal. conservation of energy & natural resources reduction in waste generated environmentally sound waste management practices.
Waste Management Produce less • EcoParks • Reduce, Reuse, Recycle, Refuse • Burn/Bury Solid Wastes • Hazardous Waste Disposal • Waste Regulation – RCRA, CERCLA (Superfund), POP’s Treaty
Best Strategy Cradle to cradle
Figure 24-2Page 533 Sewage sludge 1% Mining and oil and gas production 75% Municipal 1.5% Industry 9.5% Agriculture 13% solid waste? we produce? Fig 24.2
1st Priority - change 2nd Priority – 4R’s Last Priority – bury,pollute Secondary Pollution and Waste Prevention Waste Management Primary Pollution and Waste Prevention • Reduce products • Repair products • Recycle • Compost • Buy reusable and recyclable products • Change industrial process to eliminate use of harmful chemicals • Purchase different products • Use less of a harmful product • Reduce packaging and materials in products • Make products that last longer and are recyclable, reusable or easy to repair • Treat waste to reduce toxicity • Incinerate waste • Bury waste in landfill • Release waste into environment for dispersal or dilution What strategy does the US use for waste management? Fig. 24.3 Prevention vs. Management Low waste approach
EcoPark: Ecoindustry fig. 24.5 Material flow economy vs. Service flow economy Sludge Pharmaceutical plant Local farmers Greenhouses Sludge Fish farming Waste Surplus Waste One companies waste is another companies resource. Heat Sulfur Waste Heat Heat Waste Electric power plant Fly Oil refinery Cement manufacturer Heat Surplus Ash Natural gas Waste Waste Heat Surplus Area homes Calcium sulfate Natural gas Sulfuric acid producer Wallboard factory How does this mimic nature? Ecosystem
Reduces global warming Reduces acid deposition Reduces urban air pollution Make fuel supplies last longer Reduces air pollution Saves energy Reduces energy demand Reduces solid waste disposal Recycling Reduces mineral demand Reduces water pollution Reduces habitat destruction Protects species What are the environmental benefits of recycling? Fig. 24.8 Saves money Creates jobs Still an out put approach – Meaning?
How should we recycle solid wastes? Materials-recovery facility (MRF) Outside uses Incinerator (paper, plastics, rubber, food, yard waste) Energy recovery (steam and electricity) Food, grass, leaves Separator Shredder Pipeline Metals Rubber Glass Plastics Paper Residue Compost Landfill and reclaiming disturbed land Recycled to primary manufacturers or reformulated for new products Fertilizer Consumer (user) Sorts mixed wastes for recycling & burning - produce energy Disadvantage – discourages reuse and waste reduction Fig. 24.9
How are plastics made? Fig. 24.10 PET Polyethylene terephthalate – melted to make fleece, clothing, carpet, nonfood packaging Source materials Natural gas Petroleum Coal Refining Feedstocks Monomers (small molecules) Polymerzation Polymers Resins (giant molecules) Manufacturing Blow molding (hollow objects) Molding (solid objects) Extrusion (flat, rolled, and tubular shapes) Products Bottles, milk jugs, soda bottles, drums, containers Products Appliance housing, CDs, toys, plastic parts, aircraft, boats Products Vinyl siding, plastic film and bags, pipe
Waste-to-energy incinerator fig. 24.12 Power plant Steam Smokestack Electricity Turbine Generator Crane Wet scrubber Boiler Electrostatic Precipitator filter Furnace Conveyor Dirty water Fly ash Water Bottom ash Waste pit Conven- tional landfill Hazardous waste landfill Waste treatment How is energy produced? Advantages: Reduce trash, low water pollution, quick, easy, less need for landfills Disadvantages: High cost, air pollution (dioxins), encourages waste production, discourages recycling and waste reduction
Sanitary landfill – state of the art fig 24.14 disadvantage? Will eventually leak toxic liquids into the soil and underlying aquifers. When landfill is full, layers of soil and clay seal in trash 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 Probes to detect methane leaks Leachate storage tank Compacted solid waste Garbage Sand Groundwater Synthetic liner Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill Sand Leachate monitoring well Leachate monitoring well Leachate pumped up to storage tanks for safe disposal Leachate pumped up to storage tanks for safe disposal Clay Groundwater monitoring well Groundwater monitoring well Subsoil Leachate pipes Leachate pipes Purpose of the vent pipes? Release methane
Topsoil Sand Clay Garbage Sand Synthetic liner Sand Clay Subsoil Sanitary Landfill Solid wastes -spread - thin layers compacted/covered daily w/fresh layer of clay or plastic foam Geologically suitable sites, away from bodies of water Lined with clay/plastic before filled. Liner collects leachate, pumped to tanks, sent to sewage treatment facility.
Radioactive contaminants Inorganic metal contaminants Organic contaminants Brake fern Poplar tree Willow tree Sunflower Indian mustard Landfill Oil spill Polluted groundwater in Decontaminated water out Polluted leachate Soil Soil Groundwater Groundwater Rhizofiltration Roots of plants such as sunflowers with dangling roots on ponds or in greenhouses can absorb pollutants such as radioactive strontium-90 and cesium-137 and various organic chemicals. Phytodegradation Plants such as poplars can absorb toxic organic chemicals and break them down into less harmful compounds which they store or release slowly into the air. Phytostabilization Plants such as willow trees and poplars can absorb chemicals and keep them from reaching groundwater or nearby surface water. Phytoextraction Roots of plants such as Indian mustard and brake ferns can absorb toxic metals such as lead, arsenic, and others and store them in their leaves. Plants can then be recycled or harvested and incinerated. Phytoremediation Rhizobiltration Radioactive contaminants Phytostabilization organics Phytodegradation organics Phytoextraction inorganics
Secure Hazardous Waste Landfill fig. 24.23 Hazardous waste – toxic, ignitable, corrovsive, reactive Sources: Radioactive - medical, households, mining, businesses/factories Bulk waste Plastic cover Gas vent Earth Impervious clay Topsoil Clay cap Impervious clay cap Sand Earth Water table Leak detection system Groundwater Double leachate collection system Groundwater monitoring well Plastic double liner Reactive wastes in drums
Brownfields Abandoned industrial and commercial sites Contaminated with hazardous wastes Factories, junkyards, gas stations Being cleaned up, reused
AIR WINDS PRECIPITATION WINDS PRECIPITATION Hg and SO2 Hg2+ and acids Hg2+ and acids Photo-chemical oxidation Elemental mercury vapor (Hg) Inorganic mercury and acids (Hg2+) Human sources Inorganic mercury and acids (Hg2+) Coal-burning plant Incinerator Deposition Runoff of Hg2+ and acids Large fish WATER Deposition BIOMAGNIFICATION IN FOOD CHAIN Deposition Vaporization Small fish Phytoplankton Zooplankton Oxidation Fig. 24.26 Bacteria and acids Elemental mercury liquid (Hg) Inorganic mercury (Hg2+) Organic mercury (CH3Hg+) Bacteria Settles out Settles out Settles out SEDIMENT Cycling of mercury in aquatic environments – converted to different forms (methylmercury in humans) Biologically magnified Causes brain, nervous system damage, learning disabilitites Sources – fluorescent light bulb, coal burning