Wang Lanting, Lei Zhongfang, Zhang Zhenya, Shimizu Kazuya, Yuan Tian, Li Shengnan, Liu Siting
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Waste Manag. 2022 Aug 1;150:310-319. doi: 10.1016/j.wasman.2022.07.019. Epub 2022 Jul 25.
FeO supplementation has been reported as a high-efficient approach to enhance biogas production in anaerobic digestion (AD). Volatile fatty acids (VFAs), especially acetic acid (HAc), are considered as important products in acidification process of AD. However, the possible mechanisms involved in promotion effect of FeO on HAc production in hydrolysis and acidification processes of AD have not been comprehensively studied. This study first investigated the promotion effect of FeO on hydrolysis, acidogenesis and acetogenesis stages of AD and proposed the underlying mechanisms, using food waste (FW) as the feedstock, which is considered as the most suitable substrate for VFAs production. Results indicated that the HAc production (77.38 g-C/kg-VS) was enhanced by 79 % in AD of FW with addition of 10 g/L FeO. The duration to reach the maximum HAc production was also shortened from 14 days to 10 days. The AD tests using model substrates revealed that FeO enhanced hydrolysis, acidogenesis, and degradation of propionic acid, thus resulting in enhanced HAc production. The enhanced activities of hydrolytic and acid-forming enzymes, and electron transport system (ETS) with FeO addition further demonstrated its function as an electron acceptor to stimulate electron transfer and accelerate microbial metabolisms in AD, which contributed to the enhanced HAc production from FW.
据报道，添加FeO是提高厌氧消化（AD）沼气产量的一种高效方法。挥发性脂肪酸（VFAs），尤其是乙酸（HAc），被认为是AD酸化过程中的重要产物。然而，FeO对AD水解和酸化过程中HAc产生的促进作用的潜在机制尚未得到全面研究。本研究首先以餐厨垃圾（FW）为原料，研究了FeO对AD水解、产酸和产乙酸阶段的促进作用，并提出了潜在机制，餐厨垃圾被认为是最适合生产VFAs的底物。结果表明，在添加10 g/L FeO的FW的AD中，HAc产量（77.38 g-C/kg-VS）提高了79%。达到最大HAc产量的时间也从14天缩短到了10天。使用模型底物的AD试验表明，FeO增强了丙酸的水解、产酸和降解，从而提高了HAc产量。添加FeO后水解酶和产酸酶以及电子传递系统（ETS）活性的增强进一步证明了其作为电子受体的功能，可刺激电子传递并加速AD中的微生物代谢，这有助于提高FW中HAc的产量。
