BioResource Systems Research Group, School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, West Yorkshire, United Kingdom.
School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, United Kingdom.
J Environ Manage. 2023 Sep 1;341:117900. doi: 10.1016/j.jenvman.2023.117900. Epub 2023 May 5.
Food waste is an attractive feedstock for Anaerobic Digestion due to its high biodegradability and moisture content. Nevertheless, due to its complex structure and composition, methane yield is typically compromised with 50-60% of the theoretical maximum obtained. The well-known limitation of the hydrolysis step can be circumvented by adopting feedstock pre-treatments, such as microwave irradiation. It improves solubilization of various FW components making them more readily available for the microorganisms and reducing AD process duration. In this work different heating rates (7.8, 3.9 and 1.9 °C/min) and temperatures (85, 115, 145, 175 °C) were applied when pre-treating food waste as a substrate for AD. Increase in the solubilization of organic matter in the form of Soluble Chemical Oxygen Demand was the most significative change in FW characteristics after pre-treatment, with final temperature of 175 °C and heating rate of 3.9 °C showing a 73.19% increment. Nevertheless, process performance of AD of MW FW was optimum at 85 °C 7.8 ramp, showing no intermediate products accumulation, up to 77% more methane produced in the first week of digestion compared to the other conditions tested and reduction of 96.36% on the lag phase duration, compared to the control. On the other hand, samples treated at 175 °C, regardless of heating rate, consistently showed poor process performance, with low methane yield, possibly due to the formation of hard-to-digest compounds. This work underlines the importance of adjusting microwave temperature and power when pre-treating FW for biomethane production so the process is optimized.
食物垃圾因其高生物降解性和高水分含量而成为厌氧消化的理想原料。然而，由于其复杂的结构和组成，甲烷产量通常会受到影响，只能达到理论最大值的 50-60%。通过采用预处理方法，如微波辐射，可以克服水解步骤的众所周知的限制。它可以提高各种 FW 成分的溶解率，使它们更容易被微生物利用，并缩短 AD 过程的持续时间。在这项工作中，当预处理食物垃圾作为 AD 的底物时，采用了不同的加热速率（7.8、3.9 和 1.9°C/min）和温度（85、115、145 和 175°C）。在 FW 特性的预处理后，以可溶化学需氧量形式存在的有机物的溶解率增加是最显著的变化，最终温度为 175°C 和加热速率为 3.9°C 时，增加了 73.19%。然而，MW FW 的 AD 工艺性能在 85°C 7.8 斜坡时最佳，没有中间产物积累，与测试的其他条件相比，在消化的第一周内可产生 77%更多的甲烷，与对照相比，滞后阶段持续时间减少了 96.36%。另一方面，无论加热速率如何，在 175°C 下处理的样品始终表现出较差的工艺性能，甲烷产量低，这可能是由于形成了难以消化的化合物。这项工作强调了在预处理 FW 以生产生物甲烷时调整微波温度和功率的重要性，以便优化该过程。
