Hazards of Landfill,Burning,Tapping,Polymetric Materials,Toxic Materials,Corrosive Materials

Hazards of Landfill - The disposal of wastes in landfills presents several hazards including
(i) fires in the waste materials,
(ii) increase in the population of disease vectors like flies,
(iii) offensive odours,
(iv) methane leakage, and
(v) leaching of toxic and corrosive materials into surface and underground waters.

The water (leachate) from landfills may contain 6000-7000 mg/l total solids, COD value of 1000-2000 and 800 mg/l sodium, while the outflow from landfills may have 1000-2000 mg/l total solids, COD value of 70-80 and 300 mg/l sodium.

The risks of fires, offensive odours and increased vector populations may be circumvented by covering the waste with soil on daily basis.The risk due to methane can be removed by burning or tapping.
Similarly, the damage to the environment from landfill leachate may be avoided by lining the pit with an impermeable material like clay, soil-cement mixtures, concrete, polymeric materials and asphalts. But long-term containment with some of the linings, e.g., clay, is questionable. Therefore, specific pretreatment of the wastes to reduce toxicity is preferable.