AmbienDura

In Portugal a pilot project on municipal waste is running in which worms are the key to success. On 27 September AmbienDura visited this pilot. By using worms to take care of the organic fraction, sifting and washing other fractions, such as glass, plastics and metals, the amount of waste being landfilled can be reduced without changing the collection system radically. Although not a new technique, it is the first time is applied in Portugal; currently in a demonstration project, but soon on a greater scale in Beja. The collection system in Portugal is not yet developed optimally for a separate collection of recyclable waste streams. To prevent that the entire municipal waste stream is directly landfilled, Quercus (a Portuguese NGO) together with a partner developed this pilot. The process is rather simple: after the pre-composting phase where air is fed through the waste, the fraction is put on a ‘bed’ of worms that eat their way up through the waste. After three to four weeks, the material is then filtered, separating the compost and fractions smaller than 8 cm from bigger parts. The smaller parts are filtered again, resulting in compost and a rest fraction. The rest streams mainly consist of glass and other inert material, mixed plastics and metals, and can be washed before send of to recycling facilities. The process is of course depending on various parameters, such as the temperature, the composition of the waste and humidity.
Due to the risk of heavy metals and accumulation, the usage of the compost is preferably limited to a one-time application only. Meaning no agricultural purposes, but e.g. for forests, slopes and cover layer for landfills.
This technique could offer at the moment a solution for diverting waste streams from landfills to a better recycling. It also is a flexible system, which can be continued to use also when separate waste collection is better structured and developed. This will then also lead to a better quality of the compost.

This entry was posted on Saturday, September 29th, 2007 at 13:44 and is filed under Waste. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.