| Abstract | The effect of pH control (4, 5, 6, 7) on volatile fatty acids (VFA) production from food waste was investigated in a leach bed reactor (LBR) operated at 50°C. Stabilisation of pH at 7 resulted in hydrolysis yield of 530 g soluble chemical oxygen demand (sCOD)/kg total volatile solids (TVS) added and VFA yield of 247 g COD/kg TVS added, which were highest among all pH tested. Butyric acid dominated the VFA mix (49-54%) at pH of 7 and 6, while acetate composed the primary VFA (41-56%) at pH of 4 and 5. A metabolic shift towards lactic acid production was observed at pH of 5. Improving leachate recirculation rate further improved the hydrolysis and degradation efficiency by 10-16% and the acidification yield to 340 g COD/kg TVS added. The butyric acid concentration of 16.8 g/L obtained at neutral pH conditions is among the highest reported in literature. |
|---|
