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Solid Waste

Solid Waste. Common household and commercial waste Known as refuse, municipal solid waste (MSW) Garbage, Trash, Rubbish Does not include hazardous, nuclear waste or construction waste. Municipal Wastes: 24 lb/capita/day metal wastes plastic wastes food wastes Industrial Wastes

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Solid Waste

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  1. Solid Waste Common household and commercial waste Known as refuse, municipal solid waste (MSW) Garbage, Trash, Rubbish Does not include hazardous, nuclear waste or construction waste

  2. Municipal Wastes: 24 lb/capita/day metal wastes plastic wastes food wastes Industrial Wastes Agricultural Wastes Mining Wastes paper wastes yard wastes glass wastes Sources (MSW-Municipal Solid Waste)

  3. Solid Waste Composition (Table 11-1/11-2) • Garbage = food waste • Rubbish = combustible with some inert • Refuse = 50/50 mix of Garbage & Rubbish • Trash = 100% combustible

  4. Integrated Solid Waste Management (ISWM) • Combines • Techniques • Technologies • Management Programs • Impelemented in 1995

  5. Functional Elements of a SW Management System Waste Generation Recovery or to improve subsequent handling Waste handling, separation,storage and processing at the source Truck & routing Small to large truck Collection Separation and processing and transformation of SW Transfer & Transport Disposal

  6. Solid Waste Hierarchy Avoidance Source Reduction Recycling Materials recovery Energy Recovery Or transform to a product Landfilling Lowest in hierarchy

  7. Solid Waste Disposal • Sources • Disposal Regulations • Recycling • Composting • Collection • Processing • Landfilling • Incineration

  8. paper wastes: newspapers, books, magazines, packaging good recycling potential yard wastes: grass clippings, brush, leaves varies seasonally & geographically glass wastes: bottles, glass jars almost all can be recycled metal wastes: beverage & food containers, scrap appliances good recycling potential plastic wastes: recycling programs developed recycling codes food wastes: affected by garbage disposals Municipal Wastes

  9. SW Regulations • 1965: Solid Waste Disposal Act • early recognition of MSW • promoted better management • supported R&D • 1970: Resource Recovery Act • more emphasis on recycling & energy recovery • PHS investigated disposal of hazardous wastes • 1976: Resource Conservation & Recovery Act (RCRA) • control of hazardous waste storage, treatment and disposal • has been amended and reauthorized many times

  10. Solid Waste Law: RCRA The Resource Conservation and Recovery Act (RCRA) is the public law that creates the framework for the proper management of hazardous and non-hazardous solid waste.  Subtitle C- Hazardous Waste Subtitle D- Solid Waste

  11. SWANA THE SOLID WASTE ASSOCIATION OF NORTH AMERICA, INC. (SWANA)

  12. MSW Disposal in US

  13. Recycling Recycling is the recovery and reuse of a product which would otherwise be thrown away. Preliminary steps for a recycling program: • An accurate analysis of the sources and content of the solid waste stream. • Evaluation of any existing recycling programs. Existing programs must be integrated into the new or expanded program. • Identification of public attitudes about recycling. • Determine what markets exist for the potential recycled materials. (It does no good to collect materials for recycling if no market exists for their use!) • Determine the best recycling options.

  14. Plastic Recycling Codes • Polyethylene terephthalate, PETE-1 • High-density polyethylene, HDPE-2 • Polyvinyl chloride, PVC-3 • Low-density polyethylene, LDPE-4 • Polypropelyne, PP-5 • Polystyrene, PS-6 • Other, 7

  15. Sunset Park MRF, Brooklyn (2013)

  16. COMINGLED WASTE Commingled Recyclables: a mixture of several types of recyclable materials in one container for the purpose of separating by type at a MRF (Material Recovery Facility).

  17. Recycling Options • Drop-off Centers • can be staffed or unstaffed • Curbside Collection • more effective, but more expensive • Voluntary vs. Mandatory Recycling • enforcement? • MRF-Materials Recovery Facility

  18. Ohio University is home to the largest in-vessel composting system 

  19. Composting • controlled aerobic partial degradation of organic wastes • natural microbial processes: fungi, bacteria, protozoa • especially useful for leaves that used to be burned • waste volume reductions of 40-75% • wastes placed in windrows which are periodically mixed

  20. Elements of Composting • Collection • curbside, drop-off, required public education • Preprocessing • grinding, separating, wetting, screening • Composting Parameters • oxygen: supplied by natural aeration • nitrogen: C/N ratio varies with season • temperature: heat release • moisture: at least 50%

  21. Elements of Composting (Cont.) • Multi-Level Composting • Minimal-Level: 12x24 ft. windrows turned annually, center become anaerobic, 3 yrs. • Low-Level: 6x12 ft. windrows mixed monthly to quarterly, watered, 1.5 yrs. • Intermediate-Level: same but turned weekly, specialized equipment, 5 wks. • High-Level: 10x200 ft., forced air, water & N added, 2-10 wks., then left for 3-12 month. • Compost Uses: landscaping, gardening, farming

  22. Recycling and CompostingRates

  23. Collection

  24. PICK UP METHODS Back Yard - convenient but expensive Set out/ Set back Curbside - inconvenient but cheap

  25. Collection Vehicles Commonly used for trash collection Also used where recyclables are collected Compression to 50% See problem 11.1

  26. Typical Rear Loading collection Vehicle

  27. Side Loading collection Vehicle

  28. TRANSFER STATION To reduce number of vehicles that must travel to disposal site and, thus, save $ Transfer Stations are strategically located to accept waste from collection trucks. Waste is consolidated, compacted, and loaded into long-haul trailers for transport to landfills. This operation improves the utilization of collection equipment by minimizing transportation time and efficiently moving large volumes of waste to our disposal sites. 

  29. Solid Waste Processing • Sorting • at point of generation, transfer station, or at landfill • mechanical or manual • magnets, compressed air, inertia devices • Compaction • low pressure in collection vehicle • high pressure at transfer station or landfill • Shredding

  30. GUAM Solid Waste Transfer Station

  31. Landfilling • The legal and controlled placement of wastes in the ground • Dumping is illegal or uncontrolled • Material undergoes chemical and biological changes • Water is present which promotes biodegradation and carries away dissolved substances: Leachate • Leachate collection and recirculation

  32. Siting Restrictions • The landfill disposal regulations provide the following restrictions on landfill location: • Prohibit the placement of a landfill facility near an airport because of dangers from scavenging birds. • Require the landfill to be located outside the 100 year floodplain or the landfill design must prevent the washout of solid waste during a 100 year flood. • Prohibit the placement of a new landfill or expansion of an existing landfill into or on a wetland. • Prohibit the placement of a landfill within 200 feet of an earthquake fault. • Prohibit the placement of a landfill in an area with a high probability of a strong earthquake. • Prohibit the placement of a landfill in an area with unstable soil. • Require existing landfills which cannot meet the airport, floodplain, or unstable area requirements above, to close within five years. The state may grant a maximum of a two year extension.

  33. Operational Requirements • Provide at least six inches of daily soil cover over new solid waste placed in the landfill. • Exclusion of hazardous waste from the landfill. • Control disease vectors such as rodents and insects. • Monitor methane concentrations in the landfill and buildings. (Methane is explosive when combined with the oxygen in air.) • Elimination of most open burning. • Control public access. • Construct run-on and run-off controls for water. • Meet water quality discharge requirements (NPDES) to surface water. • Prohibit all liquid wastes except small quantities of household liquid wastes. • Maintain records indicating compliance.

  34. Design Requirements • Synthetic membrane liner at least 30 mils thick (A mil is a measurement that equals one-thousandth of an inch, or 0.001 inch. ) • Soil liner at least 2 ft. thick • Hydraulic conductivity no more than 10-7 cm/s • Other state-approved designs possible

  35. Cross Section of a Landfill

  36. Construction Methods for Landfills https://sites.google.com/site/wastemanagementalternatives/types-of-landfills

  37. Area Method: Waste deposited on surface, compacted, covered with layer of compacted soil at end of day; suitable for all terrain From Sincero & Sincero, 1996

  38. Trench Method: gently sloping land where water table is low From Sincero & Sincero, 1996

  39. Sectional View of a MSW landfill

  40. Leachate Characteristics Complex Organics Simple Organics Acetic Acid CO2 and CH4

  41. Process Microbiology Lipids, Proteins, Nucleic Acids, Polysaccharides Hydrolysis Acidogenesis Fatty Acids, Amino Acids, Monosaccharides etc Alcohols, hydrogen, CO2,formate, acetate Methanogenesis Methane and Carbon Dioxide

  42. Process Microbiology Methanogens or Methane Formers 4H2 + CO2 = CH4 + 2H2O 4HCOOH (formic acid) =CH4 + 2H2O + 3CO2 CH3COOH (acetic acid) = CH4 + CO2 CH3OH (methanol) = 3CH4 + CO2 +2H2O 4(CH3)3N (trimethylamine)+H2O=9CH4+3CO2+6H2O+4NH3 pH 6.6-7.6, alkalinity should be present; slow growth rates Y =0.06

  43. From Davis & Cornwell, 1991

  44. Bioreactor Landfills Biological degradation is accelerated to enhance biodegradation rates by addition of • Air • Water (recirculating leachate; 35-65% moisture) • Nutrients • Decomposition occurs in years instead of decades • More space available • Cost of leachate disposal reduced/beneficial use of leachate • Significant increase in landfill gas

  45. Landfill Gases Trace gas emissions are of concern as many are VOCs. Vinyl Chloride Benzene TCE Chloroform 1-1-1 TCA Methylene Chloride Ethylene dibromide Ethylene dichloride

  46. Volume of Gas Produced

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