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The Future of Waste Disposal
As population increases, what will humans do with increasing amounts of garbage?
Effects on health, aesthetics, environment
Labor, fuel, and vehicle intensive
Costly in poorer countries relative to income
Road and transportation infrastructure
Teamwork between government and waste collection agencies
250 million tons in 2010 (4.43 lbs/person/day)
Recycling facilities process 85.1 million tons a year; 54% ends up in landfills
Composting rates: 10% of solid waste in 1980 to 34% in 2010
Even in the American West, landfills are inching closer to backyards
Effects on Human Health
Higher incidence of birth anomalies (neural tube defects, great arteries and veins)
Low birth rates
Symptoms of fatigue, headaches
Vectors, such as mosquitoes and rats
Effects on Environment
Contamination of groundwater and water sources
Threats to wildlife
Damage to land and soil
around since 1970s
involves combustion to reduce volume of waste, converting to heat, gas, steam, ash, electricity
releases methane and carbon dioxide
ideally, gaseous extractions are collected to be used as fuel
still leaves some waste, and not all waste can be incinerated
Effects of Incinerators
Plants are breeding sites for vectors
Most at risk are workers in plants
In least developed countries, one-third of deaths and diseases are related to environmental causes
Advanced gasification method
External heat source
Vaporize and break down all forms of waste to simpler molecules
Plasma furnace stage
Waste is treated for preparation
Plasma arc torches for high temperatures (15,000 C)
Plasma jet arc between two electrodes
Waste is dried, vaporized and broken down
Oxygen is unnecessary
Undesirable: catalyzing of oxygen-based compounds contributes to pollution
Synthesis gas (syngas) and slag remain from reaction
Syngas formed from gasification of organic waste
Capable of combustion
Processed to remove acidic gases, metals, moisture
Mixed with air
Drive steam-based power generators
Plasma gasify expunged compounds again slag
Slag formed from inorganic products of gasification
Glasses and metals for commercial purposes
Higher efficiency, output
Complete break down/destruction of waste in plasma furnace
Deals with troublesome waste, e.g. sewage sludge
All organic waste (most municipal waste), some hazardous waste
Byproducts have own usage
Formation of soot residue
Carbon-based byproduct in high-temp process in chamber
High energy input levels
Could be prohibitive
Large upfront investment
Extensive facilities needed
Syngas can offset costs
Power the process
Sell to offsite power plants
Send it to Sweden
Sweden Wants Your Trash – NPR 10/19/12
Efficient waste to energy conversion
All combustible waste incinerated at ~1000 C, slag recycled
Hot flue gases formed from incineration heats water high-pressure steam drives turbine drives generator, produces electricity
Flue gases cleaned: dust removed in an electrostatic precipitator, other substances removed by wash in water with scrubbers, catalyst removes nitrogen oxides
Water used for cleaning flue gases treated with chemicals, remaining sludge mixed with ashes into a highly stable form, deposited in landfill
Creates energy for around 250,000 homes and powers one-fifth of the district heating system
Only 4% of Swedish garbage ends up in a landfill (eco-friendly!)
Not enough trash!
The Netherlands needs trash too!
Sweden now importing 800,000 tons of trash annually
Microbially Mediated Transformations
Use of anaerobic bacteria to break down organic waste
Occurs naturally in landfills, releasing harmful CO2 and methane
Can be controlled to extract methane and hydrogen
Some end products can be used as fertilizer (fiber, liquor)
Food Production residue
Can be slow and inefficient process for producing biofuel
Skilled manipulation of pH, temperature, alkalinity, salts required for optimal output
Current technology requires expensive reactors for consistent results
Skilled technicians required to operate effectively, hence expensive
Markets not yet developed for biofuels and fertilizers
Extended Producer Responsibility (EPR)
Tries to make producers responsible for entire life cycle of product
Assumes producers are capable of reducing environmental impact of products
Minimum recycled content standards
Energy efficiency standards
Disposal bans and restrictions
Advance disposal fees
Virgin materials taxes
Particularly challenging to reduce waste
Hazardous components, but little scrap value makes recycling expensive
Example: Lead in old TV screens
Little agreement about guidelines
Anaerobic digestion project page. 2009. Eastern Metropolitan Regional Council of Perth, Western Australia. Accessed 16 May 2012.
"Cutting Down on Colors Could Save Unilever $26 Million." Login. Web. 17 May 2012.
Environmental purchasing FAQ page. 16 April 2012. King County, Washington. Accessed 16 May 2012.
Hagerman, Eric. “Little green lies—how companies erect an eco-facade.” Wired Magazine. Condé Nast. 20 October 2008. Accessed 16 May 2012.
"Innovations in Waste Managment." - Waste Mangagement World. Web. 17 May 2012.
Kalinci, Y., Hepbasli, A., & Dincer, I. (2011, August). Exergoeconomic analysis of hydrogen production from plasmagasification of sewage sludge using specific exergy cost method. International Journal of Hydrogen Energy, 36(17), 11408-11417.
Khalid, Azeem, Muhammad Arshad, Muzammil Anjum, Tariq Mahmood, and Lorna Dawson. "The Anaerobic Digestion of Solid Organic Waste." Waste Management 31.8 (2011): 1737-744. Print.
Lemmens, B., Elslander, H., Vanderreydt, I., Peys, K., Diels, L., Oosterlinck, M., et al. (2007). Assessment of plasma gasification of high caloric waste. Waste Management, 27(11), 1562-1569.
Milanez, Bruno. "Extended Produce Rresponsibility in Brazil: The Case of Tyre Waste." Journal of Cleaner Production 17.6 (2009). Science Direct. Web.
Minutillo, M., Perna, A., & Di Bona, D. (2009, November). Modelling and performance analysis of an integrated plasma gasification combined cycle (IPGCC) power plant. Energy Conversion and Management, 50(11), 2837-2842.
Mountouris, A., Voutsas, E., & Tassios, D. (2006, August). Solid waste plasma gasification: Equilibrium model development and exergy analysis. Energy Conversion and Management, 47(13-14), 1723-1737.
Mountouris, A., Voutsas, E., & Tassios, D. (2008, August). Plasma gasification of sewage sludge: Process development and energy optimization. Energy Conversation and Management, 49(8), 2264-2271.
"Municipal Solid Waste." EPA. Environmental Protection Agency. Web. 27 May 2012.
"Resources." Urban Solid Waste Management. Web. 27 May 2012.
Scarlett, Lynn. “E-waste politics.” Reason Magazine. Reason Foundation, 4 Oct. 2000. Accessed 16 May 2012.
Stuart, Peter. “The advantages and disadvantages of anaerobic digestion as a renewable energy source.” Loughborough University. Accessed 16 May 2012.
"Waste Management: Fact Sheet." Waste Management: Fact Sheet. Web. 27 May 2012.
"World Health Assembly Closes with New Global Health Measures." WHO. Web. 27 May 2012.