Thermophilic Aerobic Digestion

Thermophilic Aerobic Digestion (TAD) is essentially a Compost process which can be used to treat waste food or other organic materials in a liquid slurry or semi-solid form.

The outline process is as below

• Feedstock is fed into a digester where air is forced through the material to encourage the growth of aerobic microbes.
• The process is exothermic, and the heat is maintained at thermophilic conditions of between 55-65°C.
• The retention time of the process is usually between two and five days, as degradation is rapid.
• Following digestion, the digestate is usually dewatered or dried. The output is a bio-fertiliser.

Thermophilic Aerobic Digestion has been used in the waste-water industry for the treatment of Sewage Sludge. Its use is relatively new for Food Waste, although there are some small pilot-scale plants in the UK and some commercial ones in development .