The exclusion of oxygen in landfills containing organic waste leads to the production of landfill gas. This odour-intensive, highly combustible gas contributes to the greenhouse effect and has a demonstrable carcinogenic and toxic effect on humans. This is due to the combination of trace substances such as hydrogen sulphide, mercaptans, perchloroethylene and vinyl chloride, which are present in addition to the main components methane, carbon dioxide and nitrogen.
If an old landfill is dug up without being appropriately treated beforehand, this not only causes an enormous odour nuisance in the vicinity and additional environmental pollution, it also poses a considerable risk to employees.
In order to avoid these effects, we subject the landfill material to prior aerobic treatment: By injecting oxygen-enriched air into the body of the landfill, the anaerobic conditions in the waste are converted into aerobic conditions. This stabilises the material before the landfill is opened, thus creating an essential prerequisite for safe and professional landfill remediation from an environmental and operational point of view.
How the Biopuster® process works:
Our specialists inject pulses of oxygen-enriched air into the waste at a pressure of 2 to 6 bars. Due to the resulting flow conditions, both larger cavities and denser areas are aerated.
This process disrupts the anaerobic methane generation process and an aerobic microbial process begins instead. The main degradation products of this process are carbon dioxide and water. The concentration of oxygen in the injected air can be adapted to the respective conditions of the landfill and is usually somewhere between 30 and 35%.
At the same time as the aeration process, the resulting reaction gas is extracted from the waste with suction lances and purified with the aid of a filter system. The amount of gas removed is about one third higher than the amount injected. This ensures that there is always a negative pressure in the treated area and prevents uncontrolled gas leakages.
One essential factor in the aerobic pretreatment of waste is ensuring that the aeration period is sufficiently long. Our tests have shown that anaerobic conditions will soon return if the exposure time is too short, i.e. only a few days. This leads to the renewed production of hazardous landfill gas.
Based on numerous successful applications of the Biopuster® process, we recommend a treatment-duration of at least three to four weeks. This is the only way we can guarantee that the material remains aerobically stabilised, even after excavation, thus permitting further treatment stages such as sorting and transport.