In a test series done by the Institute of Process Engineering of the University of Technology of Graz in which only oranges were composted in a SUPERCOMP. This test can therefore be considered as difficult, since the decomposition of oranges lasts much longer than other types of waste, and due to their high nitrogen content, other forms of bio waste must also be mixed in to even be able to compost the oranges.

Tests had been done where, for example, when composting surplus oranges in Sicily (Italy) by windrow composting, success was only achieved after adding 2/3 of other organic waste to the oranges.

“First and foremost, this test is successful because of the vertical ventilation of the composter. This creates the best conditions for the microorganisms.” (Source: Thesis by DI Nestor Manakanatas, Adviser: Univ.Prof. DI Dr. techn. Otto Wolf Bauer, TU Graz)

The successful composting exclusively tomato waste afterwards ran – not surprisingly – without any problems, as well the composting of only fresh grass clippings.

The images show a test setup in the Department of Chemical Engineering of the Technical University of Graz. Lime, rock meal and sewage treatment substrate on the order of parts per thousand were added to the 300l of varietal oranges  in the sterile laboratory environment, and after 8 months, the certainly difficult task of converting only oranges to compost was completed – see pictures 1-3.