WHAT IS WASTE?
Waste is anything, which is no longer of use to the disposer. Any unavoidable material resulting from an activity, which has no immediate, economic demand and which must be disposed of. Additionally,
Waste management is important in order to minimize the potential to cause harm to human and the environment.
Three (3) forms of waste
1. Gaseous wastes:- e.g. gas flaring, particulate dust, waste gases from stack, cement factories, stone crushing excavation activities, lime dust, asbestos dust, acid fumes, cigarette fumes.
2. LIQUID WASTES:- waste dissolved in water emanating from industrial processes (known as industrial effluent), domestic liquid, acids waste, waste oil from workshop.
3. SOILD WASTE:- e.g. broken bricks, refuse, sludge and slag, broken glass and bottles, can, plastics, paper, battery castings, plantain skin, pure water bag, etc.
There are 2 classes of waste.
1. Domestic or municipal waste
2. Industrial waste
DOMESTIC WASTES:- kitchen waste, garden waste, office waste, paper, food, wood waste water from toilet and bathrooms, laundry.
INDUSTRIAL WASTES:- e.g. scrap metals cardboard packaging, plastics, organic acid, chemical waste, oil waste, effluents or gaseous emissions (smoke, fumes, particulate dust).
EITHER OF THE WASTES CAN BE FURTHER CLASSIFIED AS HAZARDOUS OR NON-HAZARDOUS.
Hazardous waste: These are wastes that are potential hazards to human health and the environment. They are usually corrosive ignitable/explosive, or toxic, and therefore they must receive further treatment before disposal. The law requires that they be monitored from “cradle to grave”. They include dangerous waste, infectious waste, radioactive/nuclear waste, e.g. inflammable liquids chemicals, hospital waste, tank bottom, sludge, pesticides.
Non-hazardous waste: Environment friendly wastes. Biodegradable.
How to carry out Waste segregation at sources
· GENERAL WASTE: black bin, packaging material, rags
· FOOD/GARDEN WASTE; green container
· GLASS WASTE: blue container
· PAPER WASTE: black plastics bags
· IT CONSUMABLES: white container-toner, cartridges
· DANGEROUS WASTE: red container e.g. medical waste
· PLASTIC WASTE: brown container
· METAL WASTE: black metal container
· BETTERIES: grey container
WASTE DISPOSAL OPTIONS
The following are various waste disposal options;
· Surface discharge (open dump)
· Ocean dump
· Thermal treatment – incineration
· Solidification, encapsulation (compress into solid)
· Landfill – dig the ground, dump the waste and cover it. Preferably. Biodegradable wastes are buried in landfill. Hazardous wastes (nuclear reactors) are buried deep down the earth (500m) below.
PRINCIPLES OF WASTE MANAGEMENT (5STEPS)
· Waste inventorisation
· Waste characterization
· Waste segregation
· Waste minimization
· Waste treatment
· Cataloguing of all waste types, quantities and sources.
· Gives a quick insight on the magnitude of the waste problem at hand.
· Checking physio-chemical and toxogical properties.
· Selective separation of waste.
· Make for optimization of recovery of waste streams.
Involves the 4Rs
This involves physical/biological treatment by adding kerosene.
Why classify waste?
· Identification of waste with hazardous potential
· Identification of hazard waste
· Waste segregation
Ø To acknowledge the degree of waste produced daily or overtime. It acts as check and balance.
Ø Help to show the type of waste being handled from various lines. Describes types and properties.
Ø Help to recalculate waste in the categories e.g. plastics, others. It keeps people in employment.
Ø Mostly,waste can be burnt in incinerators or compressor by hydraulic press (paper waste)
OF POOR WASTE MANAGEMENT
· Foul odours – loss of community pride
· Leachate from dumpsites can poison for mosquitoes, flies and disease vector.
· Provides abundant food for rodents which transmit harmful bacteria and virus leading to epidemic – Ebola, Lassa, plague
· Fire outbreak.
management principles flow chart
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