A little bit of technology

Composting is one of the oldest forms of processing and recycling organic waste. Despite the long tradition, recycling is still highly modern, be it in the context of private households or its highly technological application on a large scale.

In a composting plant, microbiological conversions are being enhanced and accelerated by suitable technology. Thus, large quantities of organic material can be controlled and treated economically.

[k]nord’s BIOFERM^®  composting methods are marked by the principle of intensive tunnel rotting. Most of the organic waste processed comes from the separated collections of Oldenburg County and the town of Delmenhorst.

After the organic waste has passed through the weighing process it is collected in an indoor reception hall. Before the treatment of the waste continues, we conduct an intensive screening for and removal of any disturbing matter. This process is a vital component for ensuring an extremely high standard of quality in our certified composting method. It also prevents premature wear-and-tear or even damage of our plant’s technical components and hardware.

To ensure a steady composting process, the next step in the waste treatment is to generate a balanced mix of organic waste and shredded tree and bush cuttings to optimise the waste’s consistency.

Having been prepared in this way, the material is now distributed into the intensive rotting tunnels. The composting plant in Ganderkesee benefits from more than 6 of those closed-off tunnels, were a specifically developed windrow turning system loosens the compost in regular intervals and transports it to the end of the tunnel within 10-14 days.

This windrow turning system operates on rails along the sides of the tunnel and provides periodic mixing, aeration and steady transport of the waste material to the exit of the tunnel system.

The front segment of the tunnel, which was cleared by the windrow turning system, can then be reloaded with new material. This is achieved using a fully enclosed feeder operating with multiple conveyer belts. An telemetric fill level controller guarantees that the optimal amount of material is being reloaded at all times.

The automatic aeration creates ideal conditions for the microorganisms that are the essential part of the composting process. During the intensive rotting phase the temperatures in the raw material reaches highs between 60° and 70° C. The microorganisms’ metabolic processes create these high temperatures, which have the added effect of eliminating pathogen germs and unwanted seedlings.

The waste air that creates unpleasant odours is extracted from the tunnels and passes through a large air filter where it is purified and released into the surrounding air.

The seepage that builds up during the rotting process is collected and treated in a wastewater treatment facility.

Upon completion of the intensive rotting process, fresh compost has been created after 10-14 days that is not only germfree but also nearly odour-free.

After leaving the tunnels via the exit conveyer belt, the fresh compost is left to mature in a specially designated covered area. Composting pits are created using a wheel loader. Within 8-12 weeks fungi and actinomycetes decompose the more resilient substances. These complex biochemical processes transform the organic materials into humic material and clay-humic soils. Exactly these are the substances that make compost so valuable for its use in gardening.

This concludes the composting process. Finally, the material is sieved through to eliminate the remaining larger elements like stones, tree branches or foil. The finished compost can now be used to its full growth enhancing and humus producing potential in agriculture, in restoration projects or in private gardens.