WASTE AND WASTE DISPOSAL
Solid waste or refuse is constantly produced by man where he lives, work so happen to be. This waste must be handled in an appropriate manner if the environment is to be safe and sanitary. Waste are materials that are perceived to be negative value.
Concept of Solid Waste /Refuse
Solid Waste is the garbage, refuse, sludge, and other discarded solid materials that affect human’s health. Most solid waste are traced to agriculture, mining and gas and oil production and industry, while a small amount of about 2% to 5% called municipal solid waste (m500) are generated from household, businesses, and institutions (Universities, schools and colleges).
Solid waste includes rubbish or materials that are not economically useful, present in solid, liquid, or gaseous form, which originates from a wide range of human operations, such as industry, commerce, transport, agriculture, medicine and products, dead animals, manure and other discarded material but should not contain night soil.
Sources of Solid Waste/ Refuse
The sources of refuse according to Wood, de Glanville and Vaughan, (1997) are:
- Domestic/Solid Waste Refuse: This consists of left-over food, or the skins, husks and shells of potatoes, maize and coconuts; wastepaper, including wrapping and newspapers, plastic bags, worn-out clothing and shoes; and broken vessels and utensils such as cooking and water pots, bottles, tins etc.
- Street Solid Waste/Refuse: This consist of mainly of paper, plastic and food dropped by the public and commercial refuse around markets, hotels and other public places abandoned wrecks of cars.
- Industrial Solid Waste/Refuse: These are waste from industry, but they vary according to the type of industry. Some wastes are dangerous, they need special disposal.
Types of Solid Waste/Refuse
Solid waste (refuse) whether domestic, street industrial is group into three: biodegradable, non- biodegradable and poisonous substances, Wood, de Glanville, and Vaughan, (1997).
1.Biodegradable Solid Waste/Refuse (Organic): These are the refuse that come from natural materials (e.g. food, leaves/plants etc.) if left in the air or buried in the ground, gradually decompose (i.e. they are broken down by bacteria and fermentation) and slowly absorbed into the air or soil.
- Non-Biodegradable Solid Waste/Refuse (Inorganic): These are substances (e.g. bottle, tins, plastic) that does not break down naturally and remain as they for a very long time. They present a greater problem for disposal and pollution of the environment.
Refuse generated at home, offices and commercial centers are both biodegradable (perishable) item e.g. vegetable, food and non-biodegradable (imperishable) items such as plastic, bottles, metals, leather etc. The refuse is collected daily from the house, office, and commercial centers before taken to centralized point for final disposal.
- Poisonous Solid Waste/Refuse: These are the radioactive waste from industries e.g. mercury, lead, pesticides etc
Solid waste Management: This encompasses all approaches to managing the constantly accumulating solid waste, including disposal, source reduction, product reuse and recycling, and There are many methods of solid waste disposal in Nigeria and other parts of the world.
Methods of Solid Waste (Refuse) Disposal
(1) Dustbin or garbage cans
(2) open (crude) dumping;
(3) incineration (burning)