High-quality composts and fermented residues can be produced from cleanly separated bio-wastes with low foreign body content which are suitable for agricultural or gardening use. These wastes include bio-wastes from households (kitchen and garden wastes) and commercial, garden and park wastes as well as food wastes, wastes from food processing and agricultural wastes. Sewage sludges that are treated in sewage sludge composting plants are also included in the biological wastes in the waste statistics. The part of the slurry and manure volumes in Germany that is treated in bio-waste treatment plants is also counted as biological waste. It should be noted that a large part of these agricultural wastes does not come up in the waster statistics because it is not treated in waste treatment plants but recycled directly in agriculture.

• Bio-waste generates electricity and heat
  In order to make use of the energy stored in bio-waste, the bio-wastes are processed further in a fermentation plant. The bio-wastes are transformed biologically with the aid of bacteria to produce: biogas and fermentation residues. Compost is then made out of these fermentation residues. The biogas from the fermentation plant is usually incinerated in a combined heat and power unit, whereby electricity and heat are generated.
• Using the fermentation residues and compost
  Agriculture benefits from the recycling of biogenic wastes. According to the German Federal Compost Association (BGK), almost all fermentation residues are used as fertilizers. The use of fermentation residues and compost in agriculture replaces artificial fertilizers, above all, and much less peat is required also.