Anaerobic digestion of food waste is operationally challenged by rapid over-acidification. Bottom ash, a largely abandoned solid waste from biomass power generation, was supplemented in the anaerobic digestion of 2 typical food wastes of kitchen waste and fruit/vegetable waste for an attempt on this challenge. Results indicated no methane was recorded in anaerobic digestion of only food waste, indicating a complete failure by over-acidification. When bottom ash was involved, the digestion performances were significantly improved with the cumulative methane of 431.63 mL/g and 428.59 mL based on 1.0 gram total solid of kitchen waste and fruit/vegetable waste. It was found that the digestate pH was stabilized to approximately 7.5 during the digestion of these food wastes because of the excellent buffering capacity of bottom ash to the derived volatile fatty acids, indicating a main contributor to the improvement. 47.9%-71.8% promotion on digestate conductivity and the obviously enriched Methanosarcina abundance also were observed, suggesting the intensified direct interspecific electron transfer; this also had a contribution to the improved digestion. Technically, it can be proposed as a novel solution to valorization of bottom ash via facilitating the efficient anaerobic digestion of food wastes, by which a “Win-Win” strategy for these 2 bioenergy industries can be achieved to make them more sustainable.

快速过酸化在操作上对餐厨垃圾的厌氧消化提出了挑战。底灰是生物质发电的一种主要被废弃的固体废物，在厌氧消化两种典型的厨余和水果/蔬菜废物的食物残渣中进行了厌氧消化，以应对这一挑战。结果表明，仅食物残渣的厌氧消化过程中未记录甲烷，表明通过过度酸化完全失败。当涉及底灰时，基于1.0克厨房废物和水果/蔬菜废物的总固体，沼气的消化性能得到显着改善，甲烷的累积量分别为431.63 mL / g和428.59 mL。发现消化物的pH稳定在约7。在这些食物残渣的消化过程中，由于底灰对衍生的挥发性脂肪酸具有出色的缓冲能力，因此在图5中显示了这一点。消化电导率提高47.9％-71​​.8％，明显富集还观察到甲烷藻的丰度，表明种间直接电子转移增强。这也为改善消化做出了贡献。从技术上讲，它可以作为一种通过促进餐厨垃圾的高效厌氧消化来消除底灰的新颖方法，从而实现这两个生物能源行业的“双赢”战略，以使其更具可持续性。