SOLID WASTE DISPOSAL

This subject - waste has been defined in various ways such us any unavoidable material resulting from domestic activities or industrial operations for which there is no economic demand and which must be disposed of.  Waste disposal has defined 'wastes as materials which though may no longer be needed here, but may become a feedstock or raw materials elsewhere.

According to the World Health Organization Expert Committee on Solid Waste Management (1977), the term "waste" refers to all the useless unwanted or discarded materials resulting from normal community activities. This is a conceptual definition because uselessness of the waste is in the eye of the beholder. The livelihood of millions of people is dependent upon such "useless and unwanted materials" in which useful materials and energy arc increasingly being recovered. Therefore, wastes are useless, unwanted or discarded materials at a particular place and tone resulting from normal individuals or community activities. It is also a resource in a wrong place. To explain further, what is useless, unwanted and discarded by some people is useful and wanted by others. These unwanted materials are generated from domestic, industrial, commercial and agricultural operations.

From the time of creation, man has always been faced with the problem of how to effectively manage his waste products. Various agencies and organisations are also set up by the governments to ensure sanitation of the environment. And today, proper waste disposal in both rural and urban environment is an index of measuring a good government in Nigeria.

The principle of all waste management programmes is based on good environmental sanitation.    The collection and disposal of waste are therefore one of the important aspects of Environmental Sanitation. It is among the basic steps, which should be taken to ensure a disease free q safe environment in all communities. It is primarily the responsibility of the Environmental Health Technologists, Civil or Sanitary Engineers, Medical Officers of Health, etc.

CLASSIFICATION OF WASTES

Wastes can be classified into three broad headings:

1.         Liquid or Wet Waste:   This generally is called sewage. It includes industrial waste water; excreta which is  faeces and urine; sullage and storm water or rain run-off.

2.     Gaseous wastes:   These are also generally called particular matters that are discharged into the atmosphere such as fumes, dust, smog, smoke, soot, mist, fog, etc.

3.         Solid Wastes:  Solid wastes are also called refuse.  These have the following components:

(a)     Garbage:  This is purifiable or putrescible organic materials that are discarded or remaining as a result storage, preparation and consumption of food. It is in form of waste foods such as yam. plantain and cassava peelings, decaying fruits, orange husks, corn cobs, etc. Il is highly decomposable as it contains moisture. Garbage requires careful handling with frequent removal and adequate disposal because it attracts and breeds Hies, rats and other insects. Il ferments rapidly to produce obnoxious odour.

b)        Rubbish:  This consists of non-putrescible, combustible and non-combustible solid materials that arc discarded such as papers, empty cans, glasses, plastics, rags, disused   tyres,   wood,   etc.     -Rubbish   is   frequently responsible   for   the   creation   of   nuisances   when it becomes scattered by the wind and careless handling.

(c)       Street Sweepings: These consist principally of material worn   from street surfaces, dirt and other material] dropped or worn away from vehicles, leaves, sweepings from sidewalks and bits of waste papers.   They are usually putrescible enough to cause concern as a possible source of fly breeding or odour and may frequently be used for landfills. It creates dust nuisance.

(d)    Ashes/Dust:   Ashes are residues of combustion of solid fuels for heating and cooking, while dust results from street sweepings

(e)        Dead   animals:   Household   animals   as   pets,   birds, rodents, zoo animals, etc. May be knocked down and killed, by moving vehicles.   They decompose and emit offensive odour in the streets.           

(f)        Abandoned vehicles/vessels: These are found at open spaces, stores, etc.

(g)    Construction/Demolition Wastes:   These are made up of disused roofing sheets, broken blocks, rainwater or M sewage pipes, etc.

Industrial Waste: All types of refuse from industrial activities such as chemicals paints, drums, explosives, sludge, etc

Special Wastes: Those refer to wastes from hospitals or clinics - pathological wastes, radioactive wastes, explosives, etc