Techniques Of Waste Disposal
Landfills, being simple and economical, are globally the most common system of waste disposal. It involes the burial of waaste materials. Landfills that are not properly designed or managed may create several environmental hazards and diseases due to the dispersion of garbage by wind, the attraction of rats, and other similar reasons.
Landfills are normally developed in unused pits located at a distance from the developed areas so that its harmful effects can be avoided. The waste accumulated in the landfill is reduced in size by compaction to permit maximum storage of waste, and is enclosed to avoid rats or mice. Some landfills include systems for the extraction of gas that is used for the generation of electricity.
It is essential that the landfills do not pollute the surface water or the ground water, and this is ensured by lining the landfill, compaction of the upper layer, and selection of sites that are not subjected to floods. Leakage from landfill waste can be minimized by solidification with cement or asphalt.
After landfills, incineration is the most widely used method to eliminate the solid, liquid, and gaseous waste. Hazardous air contaminants are released by the burning of waste, due to which there are serious public concerns regarding environmental pollution. The combustion is generally not complete in an incinerator, due to which the gaseous emissions contain micro-pollutants that are not safe for the area near the incinerator. In countries where adequate space is not available for landfills, incineration is more practicable.