The composting of tree bark in small reactors - adiabatic and fixed-temperature experiments

The effect of temperature on the composting of bark in adiabatic and fixed-temperature reactors was studied with respect to decomposition, loss of phytotoxicity and a reduction in the production of Aspergillus fumigatus spores. High temperatures could be maintained for long periods using an adiabatic reactor and the temperature could be controlled by aeration. In fixed-temperature reactors, the optimal temperature for decomposition was either 40 or 50°C. Phytotoxicity, as determined by an in-vitro seedling assay, was reduced more quickly by 50°C composting than by 40°C. In addition the growth and sporulation of a potential human pathogen, Aspergillus fumigatus, was less at 50°C than at 40°C.