Anaerobic fermentation of food waste to connect fork to farm and store carbon in soils

Lactic acid fermentation is an anaerobic process used by specific groups of microorganisms to break down carbohydrates into sugars and produce organic acids as a byproduct. Fermentation of food waste within households is commonplace in Asia where the process is referred to as 'Bokashi'. Bokashi produces a high-quality nutrient-rich organic fertiliser that has the potential to increase soil fertility and the amount of carbon stored in soils. However, Bokashi is not common in the UK. The majority of UK food waste is anaerobically digested for biogas production. The product of anaerobic digestion (anaerobic digestate) is a low-quality organic fertiliser that is not desirable to farmers, and so biogas facilities struggle to find farmers willing to accept anaerobic digestate as a soil amendment.

This project will explore and trial the use of lactic acid fermentation (Bokashi) as an alternative to anaerobic digestion of UK food waste. You will use the University of Reading Whiteknights campus as a 'living lab' and map the foodscapes across campus to understand the types of food waste produced in different locations (e.g. catering outlets, halls of residence, offices, and classrooms). You will use benchtop-scale bioreactors to quantify emissions during traditional aerobic composting, anaerobic digestion, and lactic acid fermentation and investigate how the composition of the food waste affects these processes. You will then setup a pilot facility on Whiteknights campus to trial Bokashi using food waste generated on campus and use the resulting organic fertilizer to setup a field experiment on farmland owned by the University. The field experiment will enable you to determine the fate of carbon from the food waste in the soil environment and quantify its contribution towards long term soil carbon storage.