Environmental research

During routine maintenance of urban green areas as well as due to natural forces(wind,frost) and to plannedchanges in spatial structure of urban and industraial green areas, waste comprising lignified and ono-lignified parts of tree plants is produced.Waste wood from urban green areas is a big renewable resource which, in the form of wood chips (pieces below 50mm), may be utilised for energy production. Whilst in the case of standard forest management some foresters and ecologists object to the removal of all the biomass, including small parts,obtained from the forest, in the case of the urban green areas maintenance such removal of wood parts is a natural thing to do. At the moment, the most important component of green waste (this being wood chips) is much more frequently treated as waste than utilised. The underlying idea of utilisation is to return part of green waste to the ecosystem in the form of compost/fine bedding (mulching). The remaining part may sucessfully be used for energy production. Ash is a by-product which may be returned to the ecosystem as a fertiliser. Dumping of biomass together with municipal wastead landfills must be regarded as the worst solution from the economic and ecological point of view due to high transport and starage costs and uncontrolled emissions of methane and fermentation gases as a result of the processes taking place in wastes.

Poland