| Summary: | There is an estimated 20 million tonnes of slurry produced by 2 million dairy cows each year in the UK. The suitable treatment of dairy farm waste could address both environmental concerns and energy security. In this study, dairy farm waste was separated into liquid slurry and solid residues, and treated by Microbial Fuel Cells (MFCs) and pyrolysis to minimise the environmental impact and produce bio-energy products. The effective treatment efficiencies were achieved by using incubated slurry mixed with fresh slurry as the anodic solution in MFC reactors. Comparing MFCs with anaerobic digestion (AD) under anaerobic conditions, the highest COD removal efficiency (71 %) and total nitrogen removal efficiency (17%) were obtained in MFCs operated at 25°C and 30°C for 30 days, respectively. A higher working temperature (35°C) was found to benefit the degradation of total suspended solids (78%). The MFCs were also found to be effective for nutrient-rich solution treatment. Furthermore, the anodic solutions were pre-treated by BI-CHEM manure degrader, which could significantly benefit the bio-degradation of the TSS, COD and nitrogen removal and enhance power generation. The dairy farm solid waste was treated by pyrolysis to produce bio-oil and biochar. The highest oil yield of 51 % was obtained at 500°C. For a mixed feedstock of solid waste and bone chips (up to 15%), results suggested that co-pyrolysis could improve the biochar production yield and bio-oil quality. The optimal concentration of bone chips for oil yield was found to be 1 O~ and the optimal temperature was 500°C. The conversion technologies for dairy farm waste are discussed based on the results of the experiments in this study. The potential energy recovery of the whole treatment was 61%.
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