Ultimate Disposal Methods (Landfill) (There are three basic types of…
Ultimate Disposal Methods (Landfill)
Landfill is the primary approach for the dumping of waste generated by commercial and industrial installations and households.
Nowadays, waste man- agement and recycling are considered suitable options in disposal methods, even though landfill is likely to continue. There
There are some other nonlandfill disposal approaches: inceneration, RDF manufacture, and composting play significant roles in the disposal of waste. These
These methods are considered for short-term objectives, but in the long run, landfill is conceived as being sus- tainable.
Therefore, it is important that landfills should be designed, located, monitored, and operated to check that they are not imposing any significant threat to the natural environment and human health (Figure
There are three basic types of landfill: conventional landfills for mixed MSW, landfills for shredded waste, and monofills for specialized waste (Tchobanoglous et al. 1993)
Landfills for milled waste
This method is adopted in developed countries such as the United States. In this method, first the waste is shredded or milled to reduce the size of the solid waste before send- ing it to landfill.
The main benefit of this process is that shredded waste can be compacted to 35% greater density than normal MSW; this results in the saving of more landfill area in regions where land cost is very high
Monofills for specialized waste
Monofills are generally constructed for individual constituents of waste that cannot be placed in mixed- waste landfills
This type of waste can be electronic waste or ash from incineration plants. Incineration ash monofills produce a sulfate odor that needs to be controlled by a gas recovery system
Landfills for mixed waste:
Most of the landfills constructed in devel- oping and developed countries are for mixed waste
n developing countries where source segregation is not practiced, high amounts of organic waste and recyclables reach landfills, causing air, soil, and groundwater pollution.
This type of landfill also receives non- hazardous waste from industries and dry sludge from wastewater treatment plants
For covering waste at landfills, native soil with the lowest permeability is used to stop water percolating through it.
Landfilling is acceptable if properly conducted. If not carried out accord- ing to standard protocols, it can have negative effects on the habitat, catego- rized as short-term and long-term impacts (Table 5.5).
Landfill sites should only be selected after the following considerations:
Environmental factors include threats to the physical environment, particularly water resources. This com- prises, among other things, site topography, soils, drainage, geohy- drology, and land use.
Public recognition is the primary factor in estab- lishing a landfill in an area. It includes the potential negative influ- ence of a landfill on human health aspects of life, and local land and property values. Local public persistence toward the establishment of a landfill can hinder its development. Meanwhile, economic and public acceptance considerations have proved to identify the normal area in which a landfill is cited. Within these constrains, the most favorable substantial environment option must be found.
Economic considerations include the dis- tance from waste generation to the landfill site, the size of the site, and the accessibility and availability of land.
Sanitary Landfilling with Biogas Recovery
Sanitary landfilling is the practice of open crude dumping of MSW, which is appropriate in developing countries to manage the disposal of huge quantities of wastes because of the relative simplicity and flexibility of the waste management technology
Sanitary landfilling is an accomplished way to significantly reduce contact between the environment and waste, as waste is concen- trated in a well-defined area
The result is good control of landfill leachate and limited access of vectors to the waste and gas. In
Now a days, the implementation and practice of sanitary landfilling are seriously inhibited in most developing countries due to the inadequacy of reliable information about local contexts, as well as by insufficient funds and well-trained staff (Maier,
There are three methods of sanitary landfill, that is, trench, area or ramp, and valley and ravine area.
Area or ramp method:
Valley and ravine area method
Leachate Collection System
Leachate collection and removal are essential requirements in the development of new landfill sites for a safe environment.
Biogas Recovery from Landfill
Landfill gas is produced by the decomposition of biodegradable wastes pres- ent inside landfill sites.
Proper attention should be given to achieve the effective destruction of
harmful gases while flaring; this will reduce the environmental impacts and health risks associated with combustion products (SEPA, 2002
Landfills are a potential source of greenhouse gases and contribute about 22% of meth- ane emissions worldwide, with 48% of man-made methane emissions in the Unites States being derived from landfills in 1996