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Solid Waste

Solid Waste. Mark D. Sobsey ENVR 890-2 Spring, 2009. What is Solid Waste?. Municipal Solid Waste (MSW) AKA: “trash” or “garbage” Includes: Durable goods, e.g., tires, furniture

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Solid Waste

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  1. Solid Waste Mark D. Sobsey ENVR 890-2 Spring, 2009

  2. What is Solid Waste? • Municipal Solid Waste (MSW) • AKA: “trash” or “garbage” • Includes: • Durable goods, e.g., tires, furniture • Nondurable goods, e.g., newspapers, plastic plates/cups; containers and packaging, e.g., milk cartons, plastic wrap; and other wastes, e.g., • Yard waste, food. • Common household waste, as well as office and retail wastes • Excludes industrial, hazardous, and construction wastes Solid Waste – USA - 1989

  3. Solid Waste Definition and Classification Any material which is not needed by the owner, producer or processor. Classification: • Domestic waste • Factory or industrial waste • E-waste (electronic waste) • Construction waste • Agricultural waste • Food processing waste • Biomedical waste • Nuclear waste • Sewage solids (sludge, biosolids, compost, etc.)

  4. Typical Solid Waste Categories • Paper waste: packaging, newspapers, corrugated boxes, office paper, magazines, etc. • Biological waste: food wastes: animal or vegetable • E-waste- electronics such as computers, telephones, TVs, monitors, music systems, etc. • Industrial liquid wastes: dry cleaning solvents, motor oil, tannery wastes, distillary waste, thermal power plant cooling water, etc. • Plastic wastes: bags, bottles, buckets, packaging, etc. • Metal wastes: cans, sheet metal, tools, fasteners, etc. • Nuclear waste: unused materials from nuclear power plants • Medical wastes: solids, liquids, gases, bodily wastes, infectious agents, radioactive wastes, etc.

  5. What Happens to The Stuff No One Wants? Philadelphia’s Municipal Waste Odyssey • A 16 year journey for a cargo ship containing Philadelphia MSW • Eleven countries • Four continents • Several governments refused the cargo • Eventually, 25,000 tonnes of flyash came back to Philadelphia’s MSWL • In 2002, the cargo ship returned to the USA

  6. French Aircraft Carrier Clemenceau:A waste-laden ghost ship nobody wanted • December, 2005, The Clemenceau, a 27,000-ton warship loaded with asbestos, PCBs, lead, mercury, and other toxic chemicals • Bound for the India scrapyard of Alang (Bhavnagar district, Gujarat) • Environmental regulations lax and few workers' rights • Many shipping nations lack proper waste management policies, rules and regulations • Where rules exist, they may not be enforced. • Basel Convention (1989) • International treaty prohibiting the export of hazardous waste from rich to poor countries • Greenpeace raised awareness campaigned against the ship in India as well as in France • French President Chirac eventually announced a dramatic recall of the Clemenceau

  7. Options for Municipal Solid Waste Management • Landfills • Engineered areas where waste is placed into the land. • Waste combustors • Facilities that burn MSW at a high temperature, reducing waste volume and generating electricity • Some facilities blend MSW with other fuels • Transfer Stations • Facilities where municipal solid waste is unloaded from collection vehicles and briefly held • MSW is then reloaded onto larger, long-distance transport vehicles for shipment to landfills or other treatment or disposal facilities

  8. Municipal Solid Waste Landfills • Engineered facilities (in design and operation) • Located, designed, operated, and monitored to protect the environment and human exposure to MSW • Designed to contain and biodegrade the waste • Protect the environment from contaminants which may be present in the solid waste stream. • Landfill siting plan • Intended to prevent landfill siting in environmentally-sensitive areas • On-site environmental monitoring systems • Monitor for evidence of groundwater contamination and for landfill gas • Many new landfills collect solid waste leachate (liquid emanating from the waste and recycle or store it. • Many new landfills collect potentially harmful landfill gas emissions and convert the gas into energy (it is combustible).

  9. Landfill Properties, Practices and Policies • Location restrictions • ensure they are built in suitable geological areas away from faults, wetlands, flood plains, or other restricted areas. • Composite liners requirements • In the USA: includes a flexible membrane (geomembrane) overlaying two feet of compacted clay soil lining the bottom and sides of the landfill, • Protects groundwater and the underlying soil from leachate releases. • Leachate collection and removal systems • located above the composite liner to remove leachate from the landfill for recycling, treatment and disposal.

  10. Landfill Properties, Practices and Policies • Ban disposal of some toxic and hazardous materials • Paints, cleaners/chemicals, motor oil, batteries, and pesticides. • Leftover portions of them are “household hazardous waste” • Hazardous to health and the environment if mishandled • Many municipal landfills have household hazardous waste drop-off stations for these materials. • Unwanted household appliances (white goods) • Refrigerators or window air conditioners containin ozone-depleting refrigerants and their substitutes. • USA: federal disposal procedures for white goods with refrigerants. • Electrical waste also collected separately; not landfilled. • Contains radioactive and toxic chemicals • Not biodegradable

  11. Landfill Properties, Practices and Policies • Operating practices • compacting and covering waste frequently with several inches of soil • Reduce odor; control litter, vectors (e.g., insects, and rodents) • Groundwater monitoring • Required testing of groundwater wells to determine if wastes escape • Closure and postclosure management requirements • Cover landfills and provide long-term management of closed landfills. • Corrective action provisions • control and clean up landfill releases • achieve groundwater protection standards • Financial assurance • Funding for environmental protection during and after landfill closure

  12. Bioreactor Landfills • Operated to rapidly transform and degrade organic waste by microbial processes • Increase waste degradation and stabilization through the addition of liquid and air • Differs from the traditional “dry tomb” municipal landfill approach. • Three different general types of bioreactor landfill configurations: • Aerobic: • Leachate is removed from the bottom, piped to liquids storage tanks, and re-circulated into the landfill in a controlled manner. • Air is injected into the waste mass, using vertical or horizontal wells, to promote aerobic activity and accelerate waste stabilization.

  13. Bioreactor Landfills • Anaerobic • Add moisture to the waste mass as re-circulated leachate or other sources to obtain optimal moisture levels. • Anaerobic biodegradation oxygen to produces landfill gas • Primarily methane • can be captured to minimize greenhouse gas emissions and for energy projects. • Hybrid (Aerobic-Anaerobic) • Accelerates waste degradation by employing a sequential aerobic-anaerobic treatment • Rapidly degrades organics in the upper sections of the landfill • Collects gas from lower sections. • Hybrid operation results in earlier onset of methanogenesis compared to aerobic landfills

  14. Bioreactor Landfills • Accelerate the decomposition and stabilization of waste. • Leachate is injected to stimulate natural biodegradation processes. • Other supplemental liquids such as stormwater, wastewater, and wastewater treatment plant sludges are often added to maintain moisture content • Enhance microbiological processes by controlling moisture content • Differs from landfills that just recirculate leachate for liquids management. • Landfills recirculating leachate may not operate as optimally. • Moisture content is the most important factor for accelerated decomposition. • Maintain optimal moisture content near field capacity (~35-65%) • Add liquids when necessary to maintain that percentage. • The moisture content, combined with the biological action of naturally occurring microbes decomposes the waste. • The microbes can be either aerobic or anaerobic. • Side effect: production of landfill gas (LFG) such as methane at higher rate than traditional landfills.

  15. Potential Advantages of Bioreactor Landfills • Waste decomposition and biological stabilization can occur in a much shorter time than in a traditional “dry tomb” landfill • Potential decrease in long-term environmental risks and landfill operating and post-closure costs. • Decomposition and biological stabilization in years vs. decades in “dry tombs” • Lower waste toxicity and mobility due to both aerobic and anaerobic conditions • Reduced leachate disposal costs • A 15-30 % gain in landfill space due to an increase in density of waste mass • Significant increased LFG generation that, when captured, can be used for energy use onsite or sold • Reduced post-closure care

  16. Bioreactor Landfill Gas - LFG • LFG of bioreactor landfill consists primarily of: • Methane, carbon dioxide, lesser amounts of volatile organic chemicals and/or hazardous air pollutants • LFG is generated earlier in the process and at a higher rate than in the traditional landfill. • The bioreactor LFG is generated over a shorter period of time • LFG emissions decline as accelerated decomposition depletes the source waste faster than in traditional landfills. • The net result: bioreactor landfill produces more LFG overall than does the traditional landfill.

  17. MSW Combustion or Incineration • Controlled burning process that reduces solid waste volume; Called refuse derived fuel (RDF) facilities • Properly equipped, they can convert water into steam to fuel heating systems or generate electricity. • They are equipped to recover recyclables (e.g., metals, cans, glass) first • Then the combustible fraction is shredded into fluff for incineration. • IN USA >20% of MSW incinerators use RDF. • Contrast with mass burning: • MSW is introduced "as is" into the combustion process • Considerable air pollution is produced • Some mass burn facilities have no air pollution controls

  18. RDF Facilities and Air Pollution Control • Pollution control technologies reduce gases emitted into the air: • Scrubbers: devices using a liquid spray to neutralize acid gases • Filters: remove tiny ash particles • Burning waste at extremely high temperatures: • destroys chemical compounds and pathogens. • Regular testing to ensures that residual ash is non-hazardous before being landfilled. • About 10% of the total ash formed in the combustion process is used for beneficial use such as daily cover in landfills and road construction

  19. Solid Waste Transfer Stations • Facilities where MSW is unloaded from collection vehicles and briefly held. • Held waste is reloaded onto larger, long-distance transport vehicles for shipment to landfills or other treatment or disposal facilities. • Pros: • Combining loads of several individual waste collection trucks into a single shipment saves money on labor and operating costs of waste transport the to a distant disposal site. • Reduces the total number of vehicular trips traveling to and from the disposal site. • Cons: • Can cause increased traffic in areas located. • If not properly sited, designed and operated they can cause problems for residents living near them and cause hazards on the roads they travel.

  20. Backyard Burning • Burning of household trash by residents on their own property. • Trash typically burned includes paper, cardboard, food scraps, plastics, and yard trimmings • any materials that would otherwise be recycled or sent to a landfill. • Burning often occurs in a burn barrel, homemade burn box, wood stove, outdoor boiler, or open pit. • Air emissions from backyard burning are released directly to the atmosphere without being treated or filtered. • Common in developing countries

  21. Why People Burn Household Waste • People burn trash for various reasons • It is easier than hauling it to a local disposal site • They avoid paying for regular waste collection service. • In some places it is the only way a rural dweller can easily get rid of/manage their waste. • In developed countries like the USA, many state, local and tribal governments prohibit or restrict some or all backyard burning of waste. • Even where restrictions exist, however, many people continue to burn.

  22. Health Risks of SW Burning • Burning waste is harmful to health and the environment. • Research indicates it to be far more harmful to health than previously thought. • Increases the risk of heart disease, aggravates respiratory ailments such as asthma and emphysema, and cause rashes, nausea, or headaches. • Produces harmful quantities of dioxins, a group of highly toxic chemicals that settle on crops and in waterways • Eventually winds up food to impact health

  23. Waste Barrel Burning and Dioxins • Typically, dioxins are absent in materials before incineration. • They are produced when waste is burned. • Significantly higher dioxin levels are created by burning SW in barrels than in municipal incinerators. • Burn barrels get limited oxygen so burn at low temperatures • Produces dioxins, much smoke (carbonaceous particulates) and other pollutants. • Large, regulated incinerators have stringent pollution control systems that reduce dioxin emissions primarily by preventing their formation. • Backyard burning is also hazardous because it releases pollutants at ground level, where they are more readily inhaled or incorporated into the food chain.

  24. Health-related Pollutants from Backyard Burning • Dioxins, • Particle pollution, • Polycyclic aromatic hydrocarbons, • Volatile organic compounds, • Carbon monoxide, • Hexachlorobenzene • Ash

  25. Dioxin Exposure and BYB • Dioxins and "dioxin like“ cds: 30 highly toxic chlorinated organic chemicals. • Produced naturally in small quantities, but primarily from human activity. • Industrial processes, ex. chlorinated chemical manufacture & metal smelting • Largest quantified source is uncontrolled burning of HH trash (BYB). • Only small amounts of chlorinated materials in waste are needed to support dioxin formation when burning. • So, even when materials containing high levels of chlorine, such as PVC, are removed from HH trash, burning the waste still creates dioxins • Almost all HH waste contains trace amounts of chlorine.

  26. BYB and Dioxin Exposure Pathways • Much of the dioxins created and released into air by BYB settle on plants • The plants are eaten by food animals, dioxins are stored in their fatty tissue. • People are exposed by eating meat, fish, and dairy products, • especially those high in fat. • Dioxins then accumulate in the fats of dairy cows, beef, poultry, and swine, making human consumption of these harmful chemicals difficult to avoid. • BYB occurs most commonly in rural farming areas where dioxin emissions can more easily be deposited on animal feed crops and grazing lands.

  27. Dioxins and Human Health • Dioxins are classified as persistent, bioaccumulative, and toxic pollutants (PBTs). • PBTs are highly toxic, long-lasting substances that accumulate in the food chain to levels harmful to human and ecosystem health. • Persistent: remain in the environment for extended periods of time. • Bioaccumulative: concentrations increase moving up the food chain. • Animals at the top of the food chain (such as humans) tend to have the highest dioxin concentrations in their bodies. • Dioxins are potent toxicants that potentially produce a broad spectrum of adverse effects in humans. • They alter the fundamental growth and development of cells, leading to many kinds of adverse health impacts. • Reproduction and development • Immune suppression • Disruption of hormonal systems • Cancer

  28. Particulate Pollution • Particulate matter, or PM • Microscopic particles released by open burning • Particles are small enough to enter the lungs • Less than or equal to 10 um in diameter • Cause numerous health problems • Aggravate respiratory conditions such as asthma and bronchitis • Associated with cardiac arrhythmia (heartbeat irregularities) and heart attacks. • People with heart or lung disease, the elderly, and children are at highest risk from exposure to particles.

  29. Polycyclic Aromatic Hydrocarbons - PAH • A group of chemicals commonly found in particulate matter (or smoke and soot) released from backyard burning. • Formed from the incomplete combustion of certain materials. • Some are carcinogenic

  30. Volatile Organic Compounds-VOC • VOCs are produced by open burning. • Many VOCs are harmful to humans. • They also contribute to ground-level ozone pollution, i.e., smog • Smog can worsen respiratory, heart, and other existing health problems. • Inhaling certain VOCs can lead to eye, nose, and throat irritation; headache; loss of coordination; nausea; and damage to liver, kidney, and central nervous system.

  31. Carbon Monoxide • Carbon monoxide (CO) at low levels of exposure causes a variety of neurological symptoms: headache, fatigue, nausea, and vomiting.

  32. Hexachlorobenzene (HCB) • A highly persistent environmental toxin that degrades slowly in air • Undergoes long-range atmospheric transport • Bioaccumulates in fish, marine animals, birds, lichens, and animals that feed on fish or lichens. • Based on animal toxicological studies, long-term low-level exposures may • damage the developing fetus • cause cancer (A probable human carcinogen) • lead to kidney and liver damage • cause fatigue • Cause skin irritation

  33. Ash • Ash residue can contain toxic metals such as mercury, lead, chromium, and arsenic. • These metals can be toxic when ingested. • Ingestion of hazardous amounts of lead can cause high blood pressure, cardiovascular problems, kidney damage, and brain damage. • Lead is a potent neurotoxin to infants and children • Causes developmental disorders, decrements in IQ, learning disabilities • People scatter ash in their gardens or bury it on their property • Garden vegetables can absorb and accumulate the metals in ash, which can make them hazardous to eat. • Children playing in the yard or garden can incidentally ingest soil containing these metals. • Rain can wash ash into ground and surface water, contaminating drinking water and food.

  34. Methods to Reduce Solid Waste • Source reduction • Alter the design, manufacture, or use of products and materials to reduce the amount and toxicity of what gets thrown away. • Recycling • Sorting, collecting, and processing materials to manufacture and sell them as new products. • Composting • Decomposing organic waste, such as food scraps and yard trimmings, with microorganisms (mainly bacteria and fungi) to produce compost. • Compost is the biologically stabilized residual organic material that can be used as a soil amendment or as a medium to grow plants.

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