- Slides: 14
Solid Waste Management Solid waste: is any solid or semi-solid material that has been discarded Each year, Canadians generate 30 million tonnes of solid waste (that’s 250 CN Towers or 4, 000 African elephants!)
Waste stream: the movement of waste from its sources to its final destination Solid waste enters the waste stream from three main sources: agriculture, industry, and municipalities.
Agriculture Solid Waste Farms, ranches, feedlots and many slaughterhouses are the sources. Agriculture solid waste is made up of animal waste and organic matter that is left over after harvesting and processing crops and animals.
Industrial Solid Waste Industries such as manufacturing, construction, mining and other industries are sources. These wastes range from chemicals used to wastes produced during construction or demolition. Most industrial waste is recycled by industry.
Municipal Solid Waste (MSW) MSW includes all garbage – including items that can be recycled and composted – from homes, businesses such as office buildings, and institutions. Canada has the dubious distinction of being among the world leaders in the yearly production of MSW.
Provincial and territorial governments manage MSW. However, responsibility for collecting and treating the waste is often passed on to municipal or regional governments.
Today, especially in developed countries, the final destination for most municipal solid waste is a landfill site. Landfill: a disposal site for solid waste where the waste is buried between layers of soil, filling in low-lying ground Landfills isolate waste from ground water, air, and surrounding soils. Isolation from ground water is made possible by large, impermeable liner that is buried deep into the ground.
Landfills provide several benefits to the environment. First, they are an immediate solution for solid waste management. Some landfills use gases produced by waste to generate electricity. Without landfills, waste would enter the environment directly.
Leachate: liquid from landfills composed of chemicals from garbage Rubber or clay liners are used to trap leachate. Drainage systems are installed to monitor and collect leachate before it leaves the landfill.
Landfill gas is created by bacteria as they break down food and other organic material in landfills. The gas is a mixture of mostly methane and carbon dioxide, both of which are potent greenhouse gases. Technology can help manage landfill gas. Gas capture and combustion converts methane into carbon dioxide.
Available Space Today, about 80% of municipal solid waste from Canada and 55% from the US goes into landfills. An ongoing debate over how to replace lost landfill capacity is developing where population density is high and available land is scarce. Where do places like Toronto, New York, and LA find space for new landfills?
Alternatives 1. Thermal Treatment: processing of solid waste at high temperatures As of 2013, Ontario, Quebec, B. C. , Alberta, and P. E. I have thermal treatment facilities.
Advantages: - Reduces the volume of waste (by 10 -20%) - Production of energy (see next slide) Disadvantages: - Thermally treated waste can enter the atmosphere in the form of ash and gases - Facilities use pollution control technologies to treat or capture this waste (which we talked about!)
2. Exportation Where waste is exported to different cities, states or countries. For Example: In 2011, New York shipped nearly 11 tonnes of waste every day to landfill sites in other states! Disadvantage: Expense! In 2011 it cost New York 300 million dollars to transport its waste.