Physico-chemical Investigation On Dumpsite Leachate
[A CASE STUDY OF ILORIN METROPOLIS]

Waste generation inside Malaysia was found to depend on the resource of municipal solid waste (MSW). The rate of generation varied depending on the premises (houses, shops, etc.) (Figure 2.2) with housing areas producing the largest quantity of waste while hospital produced the smallest quantity (Agamuthu, 2001).
2.2.2    Sanitary landfills
Sanitary landfill or controlled tipping is defined as a “method of disposing refuse on land without creating a nuisance or hazard to public health or safety by utilizing the principles of engineering to confine the refuse to the smallest practical area and to reduce it to the smallest practical volume and cover it with a layer of earth at the conclusion of each day’s operation or at such more frequent intervals as may be necessary”. The main aim of a sanitary landfill is to use it for a longer time for disposal of solid waste with less negative effect to the ecosystem. Also, if the sanitary landfill is designed for energy extraction, the landfill gas can be used as a source of energy. Moreover, in some countries, reclamation of land is done especially where land is limited (Agamuthu, 2001).
         Although, the sanitary landfills have a lot of benefits but they also have some disadvantages. Landfills require usable land which should be located near several cities. Unfortunately land is in short supply and sometimes expensive. Secondly, sanitary landfills can pollute ground water with toxic waste like pesticides and paints. Another disadvantage is that they produce methane gas which causes air pollution. They also tend to destroy many habitats, especially wetland. Finally, it may cause loss of resources which may become extinct (Chiras, 2001).
2.2.2.1 Incineration    
Incineration of MSW has many advantages including a significant reduction in volume (about 70–90%), recovery of energy and complete disinfection (Abanades et al., 2001) However, when compared with other methods, it has some disadvantages, for example it is expensive, generates fly and bottom ashes, emits toxic gases and particulate matters into the atmosphere, and requires much energy (Nabajyoti et al., 2007).
Sometimes the ash is used as a replacement for quarried aggregate in construction (Scottish Environmental Protection Agency, 2006). The composition of the solid residues produced during incineration depends mainly on the waste characteristics (Margarida et al., 2007).
2.2.2.2 Composting
Currently, one of the problems in developing countries is the management of organic waste. Most of the countries are trying to reduce the amount of organic waste which is deposited in landfills by applying different technologies. Composting is a more appropriate technique for recycling organic waste and changing it into ecologically stable product beneficial for the soil (Ouatmane et al., 2000; Jouraiphy et al., 2005).