Solid Waste

Solid waste Solid waste characteristics Solid waste arises from human or animal activities. • Heterogenous (also called urban waste): municipal wastes (garbage, refuse, sludge). Waste generation encompasses activities in which materials are identified as no longer being of value and are either thrown away or gathered together for disposal.  Biodegradable waste: food, green waste, paper  Recyclable material: glass, cans, certain plastics  Inert waste: construction and demolition waste, dirt, rocks..  Composite waste: clothing, plastics  Domestic hazardous waste & toxic waste: medication, paint, chemicals, light bulbs.. • Homogenous: industrial, commercial and institutional waste.

Environmental & health concern • • •

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Pollution: overloading of wastes breaks down the ecosystem, causing environmental pollution, a deterioration in environmental quality. Aesthetical requirements: requirements regarding the impact of solid waste on the view. Conservation of resources: Raw materials are being used at a faster rate than they are being replaced. This has led to calls for reduction of wastes and recovery of materials from the wastes. Human diseases: 22 human diseases are reported to relate to improper solid waste management. Unattended waste lying around attracts flies, rats and other creatures carrying infectious diseases and in the worst case causes plagues. Physical and chemical hazards: containers of chemicals may not be completely empty when thrown away, which may, even in small quantity, cause a threat to humans and animals.

Treatment and disposal • • • •

Biological treatment: bacteria decompose waste. Aerobic compost and anaerobic compost. Thermochemical treatment: incineration/combustion, gasification, pyrolysis. Chemical treatment: hydrolysis Landfill