Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, School of Environment, Tsinghua University, Beijing 10084, China.
Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, School of Environment, Tsinghua University, Beijing 10084, China.
Waste Manag. 2018 Jan;71:719-727. doi: 10.1016/j.wasman.2017.03.019. Epub 2017 Mar 18.
Excessive acidification frequently occurs in the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) at high organic loading rates (OLR), due to the accumulation of non-acetic volatile fatty acids (VFA). In this study, the performance of Fe in enhancing various VFA production and metabolism was investigated. The butyric acid concentration in a high OLR reactor with Fe addition decreased from 7200 to 0mg/L after a short lag phase, and the total VFA (TVFA) concentration also decreased substantially. The corresponding dominant acidogenesis type also changed from butyric type to propionic type fermentation. Furthermore, the CH yield of the reactor with added Fe was approximately 595ml CH/g VS, which was an increase of 41.7% compared with the biochemical methane potential (BMP) test results in controls without added ZVI. A microbial diversity analysis, using high throughput sequencing, showed that Methanofollis and Methanosarcina were dominant in terms of the archaeal structures of the Fe reactor at the butyric converting stage; however, Methanosaeta was predominant in the reactor during the control BMP test. These results suggested that Fe can convert non-acetic VFA to acetic VFA and improve the CH yield by enhancing the activity of methanogens.
在高有机负荷率（OLR）下，由于非乙酸挥发性脂肪酸（VFA）的积累，有机固体废物（OFMSW）的厌氧消化过程中经常会发生过度酸化。在本研究中，研究了 Fe 对各种 VFA 产生和代谢的促进作用。在添加 Fe 的高 OLR 反应器中，丁酸浓度在短的滞后阶段后从 7200 降至 0mg/L，总 VFA（TVFA）浓度也大幅下降。相应的主导产酸类型也从丁酸型发酵转变为丙酸型发酵。此外，添加 Fe 的反应器的 CH 产率约为 595ml CH/gVS，与未添加 ZVI 的对照物的生物化学甲烷潜能（BMP）测试结果相比，增加了 41.7%。高通量测序的微生物多样性分析表明，在 Fe 反应器的丁酸转化阶段，甲烷丝状菌属和产甲烷菌属在古菌结构方面占优势；然而，在对照物的 BMP 测试期间，产甲烷菌属占主导地位。这些结果表明，Fe 可以将非乙酸 VFA 转化为乙酸 VFA，并通过增强产甲烷菌的活性来提高 CH 产率。
