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Organic waste bin (first from left) in Heidelberg

Biowaste is the organic waste of animal or vegetable origin that occurs in a household or business and can be broken down by microorganisms , living organisms or enzymes . These include, for example, leftover food and lawn clippings. Biowaste is usually collected separately in the so-called biowaste bin and treated separately through composting and fermentation . The resulting compost and digestate are often returned to the environment, for example in horticulture and agriculture .

According to the definition of the EU Waste Framework Directive, biowaste includes garden and park waste, waste from landscape maintenance, and food and kitchen waste (from households, restaurants, catering, retail and processing in the food industry). Waste from agriculture and forestry is not included. Biowaste should not be confused with the broad term “ biodegradable waste”, which also includes other biodegradable materials such as wood , paper , cardboard and sewage sludge .

In the European Union, between 118 and 138 million tonnes of biowaste are generated annually, of which around 88 million tonnes come from municipal waste. By 2020, the volume is expected to increase by 10%.

Situation in Germany

Police Ordinance on the Collection of Kitchen and Food Waste of October 19, 1939

From 1990 to 2004, the collection of biowaste in Germany increased tenfold to 10 million tons / year. Since then, the recording has remained constant within the usual fluctuations.

However, the residual waste still contains 48% biogenic waste, which the citizens did not dispose of in the organic waste bin or composting themselves. This waste has been thermally disposed of in the incinerator since 2005. There, the wet organic waste reduces the average calorific value of the waste. Contrary to popular opinion, this effect is desired by the operators because it protects the furnace grates and the replacement intervals can be extended. The very high proportion of plastics in residual waste (packaging, etc.) led to an undesirable increase in the calorific value, so that "cooling" of the material to be burned is welcome. The savings in maintenance costs far exceed the loss in calorific value. However, newer waste incineration plants are often designed for higher calorific values.

Biowaste Ordinance

The digestate and compost resulting from the treatment of biowaste must meet special hygienic requirements, which have been regulated for Germany in the Biowaste Ordinance since September 21, 1998 .

The term for biowaste is defined in the Biowaste Ordinance. Biowaste includes waste of animal or vegetable origin for recycling that can be broken down by microorganisms, soil-borne organisms or enzymes. These are then specified in more detail in Appendix No. 1 of the Biowaste Ordinance. On the other hand, soil materials without significant amounts of bio-waste and plant residues that occur on forest or agricultural areas and remain on these areas do not belong to the bio-waste.

Furthermore, the Biowaste Ordinance differentiates between treated and untreated biowaste as well as mixtures thereof. Biowaste is considered treated if it has been subjected to either aerobic (composting), anaerobic (fermentation), other hygienic treatment or a certain mixture (mixture). A mixture exists when z. B. bio-waste is mixed with certain farmyard manures, soil materials or peat.

Composting inevitably creates anaerobic zones in which greenhouse gases are formed, mainly methane. Compost heaps, triangular heaps and other forms of composting are serious factors in the global production of greenhouse gases.

Comparison of biogas raw materials
material Biogas yield
in m 3 per ton of
fresh mass
Corn silage 202 52%
Grass silage 172 54%
Rye GPS 163 52%
Pressed sugar beet
125 52%
Fodder beet 111 51%
Biowaste 100 61%
Chicken litter 80 60%
Pig manure 60 60%
Cattle manure 45 60%
Grain Meat 40 61%
Pig manure 28 65%
Cattle manure 25th 60%

Recovery and use

Since biowaste is biomass , its large-scale energetic utilization can also be considered. Wet material as well as slaughterhouse waste can be used in biogas plants , dry material for direct combustion or for process-technical utilization e.g. B. to BtL fuel .

A process that has been common in the USA for decades is the shredding of domestic organic waste in the kitchen. There, the organic waste is ground into small particles with a kitchen waste grinder, washed away with the waste water and thus fed to waste water treatment . In the sewage treatment plant , this is used to produce material for the production of biogas ( sewage gas ).

On the other hand, on February 13, 2007, the European Parliament demanded in its 1st reading on the amendment to the Waste Framework Directive that bio-waste should primarily be recycled. Three years after the directive came into force, the member states are to set up their own systems for the separate collection of bio-waste as well as quality assurance systems.

Web links

Wiktionary: Biowaste  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Communication from the Commission on future steps in the management of biowaste in the European Union, reference: COM (2010) 235 final
  3. Fricke et al., 2003
  4. Text of the Biowaste Ordinance
  5. Fachagentur Nachwachsende Rohstoffe e. V. (FNR): Biogas basic data Germany. (PDF; as of October 2008). Source for all information except for pressed pulp.
  6. Biogas yields of different substrates, division potatoes / beets, see pressed pulp ensiled .