Theory

• The costs of collecting and treating waste are high. In LICs, solid waste management is usually a city's single largest budgetary item and it is common for urban authorities to spend 20 to 50 per cent of their budget on solid waste management
• Environmentally, waste is a large source of methane. Waste also contributes to water, ground and air pollution.
• Untreated or uncollected water can lead to health problems such as respiratory ailments, cholera and dengue fever
• Many city authorities are struggling to collect increasing quantities of urban waste. The 2012 World Banks report on waste found that 30 to 60 per cent of solid waste in LICs is uncollected. (Egypt generates 80 million tonnes of solid waste per year)
• Landfilling and thermal treatment of waste are the most common methods of waste disposal in HICs. Most LICs dispose of their waste in open dumps, which may be unregulated (not collected or supervised by regulation of law).
• Resource recovery is the selective extraction of disposed materials for a specific next use, such as recycling, composting or energy generation. Recycling is carried out when materials from which the items are made can be reprocessed into new products.
• Urban mining is the name given to the process of recovering compounds and elements from products, buildings and waste which would otherwise be left to decompose in landfills
• The global waste trade is the international trade of waste between countries for further treatment, disposal, or recycling. Toxic and hazardous wastes are often exported from high to low-income countries, yet do not have safe recycling processes or facilities, leading to contamination of the surrounding environment.
• Incineration of waste can reduce the volume of disposed waste by up to 90 per cent. General waste can be safely burned at high temperatures to produce electricity and heat - energy from waste
• Burial is the placement of waste excavations, such as pits or landfills, which can be natural or constructed. Landfill sites are a common final disposal site for waste from urban areas. In the UK, most now control and collect the gas that is released by the decomposing waste, often using it to generate electricity through turbines.