Atliekų sąvartyno išskiriama tarša

Abstract

The main pollutants from solid waste landfill - biogas and leachate Landfill gas consists of 50-60% methane and 35-40% carbon dioxide. It also contains trace levels of other gases such as hydrogen sulphide and organic substances that give it its characteristic sweet, sickly smell. Landfill gas poses a threat to the local environment: it can cause fires, explosions and asphyxiations if allowed to migrate to surrounding property. Three processes — bacterial decomposition, volatilization, and chemical reactions — form landfill gas. The biodegradation of organic waste follows a pattern of five phases. These five phases are fundamental, and they affect the biogas composition. Landfill leachate is generated by excess rainwater percolating through the waste layers. Combined physical, chemical and microbial processes in the waste transfer pollutants from the waste material to the percolating water. Leachate from landfills contains a wide range of contaminants: dissolved organic matter, inorganic elements, heavy metals and other components. Where leachate enters the groundwater, significant changes in water quality are observed and complicated biogeochemical patterns develop in the leachate pollution plume.