Greenhouse gas emission reduction by aerobic treatment of old landfills
Old landfill have a big contribution to greenhouse gas emissions an should be treated in the future worldwide to avoidlandfill gas emissions. Even in industrialized countries old landfills have a big contribution to the greenhouse effect.
Typical project aims for aerobic treatment of old landsfills are the rehabilitation of old landfills. Those landfills are often shallow or small, have no bottom sealing, no leachate and gas collection systems. The top cover consists of a material without any sealing function.
Therefore environmental impacts occur at the landfill. Landfill gas emissions into the atmosphere and leachate emissions into the groundwater take place.Therefore the mentioned emissions will occur in the near future. During that rehabilitation project the waste will be partly aerated, excavated, segregated and aerated (treated) during that process. The remaining inert fraction of the waste will be refilled in the original site. Part of the material will be used, not inert materials will be transported to a landfill for disposal. Most of the utilized materials are plastic, tyres, wood and metal. As those materials behave neutral under considerations of the green house gas effect they will not considered but the amount of those materials has to be reduced from the amount of excavated material. The remaining waste is designated treated waste.After the excavation and refilling of the material the site can be used for housing or commercial activities or for other municipal purposes.
Concerning environmental aspects the project is therefore suitable to avoid landfill gas emissions in the future through aeration of the waste and to avoid further methane production and emission.
Aim of the project is to avoid landfill gas emissions from an old landfill by excavating or aerobically treating of the waste. Gas emissions occur as tests at gas probes often show. As there is often no legal duty a gas collection system is not installed. Furthermore old and wild dumps are not suitable for a gas collection system. Dangers for the environment and human beings because of explosive landfill gas mixtures do not exist so that no additional site specific measures are necessary. Therefore landfill mining or aerobic treatment of the waste is the only method to reduce landfill gas emissions.
The amount of landfill gas emissions which will be reduced depend directly from the degradable organic waste fraction which is still left in the landfill and which is reduced by the mining and treatment actions.
The monitoring of the process and the amount of the reduced emissions based on direct measurements of the amount of the degradable waste fraction before and after excavating or treating and the measurements of the caused emissions because of the project activities as there is energy consumption for excavation, transport, and treatment and sometimes for the disposal of the treated material.
