State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Water Res. 2024 Jan 1;248:120897. doi: 10.1016/j.watres.2023.120897. Epub 2023 Nov 20.
The recovery of renewable bioenergy from anaerobic digestion (AD) of sludge is a promising method to alleviate the energy problem. Although methane can be effectively recovered through sludge pretreatment by cation exchange resin (CER), the simultaneous enhancement of hydrogen and methane generation from AD using CER has not been extensively investigated. Herein, the effect of CER on the sequential recovery of hydrogen and methane and the corresponding mechanisms were investigated. When CER is introduced, the maximum increases for the hydrogen and methane production are 104.7 % and 35.3 %, respectively, confirming the sequential enhancement effects of CER on the hydrogen and methane production. Analyses of the variations in the main biochemical components with and without the effect of CER demonstrate that CER promotes sludge organic solubilisation, hydrolysis, and acidification in both hydrogen- and methane-production stages. Moreover, investigations of variations in the solid-liquid interfacial thermodynamics and removal rates of main multivalent metals of sludge reveal that the ion exchange reactions between the CER and sludge in the hydrogen-production stage provide the direct driving force of effective contact between bacteria and organic particulates. Additionally, the residual effect of the CER during methane production reduces the energy barrier for mass transfer and provides a driving force for this transfer. Further analyses of the microbial community structure and metagenomics indicate that CER directly drives the enrichment of hydrogen-producing bacteria (+ 15.1 %) and key genes encoding enzymes in the hydrogen-production stage. Moreover, CER indirectly induces the enrichment of methane-producing anaerobes (e.g. Methanosaeta: + 16.7 %, Methanosarcina: + 316.5 %); enhances the bioconversion of different substrates into methyl-coenzyme M; and promotes the metabolism pathway of acetoclastic process and CO reduction in the methane-production stage. This study can provide valuable insights for simultaneously enhancing the production of hydrogen and methane from AD through sequential recovery.
从污泥厌氧消化 (AD) 中回收可再生生物能源是缓解能源问题的一种有前途的方法。虽然阳离子交换树脂 (CER) 可以有效地通过污泥预处理来回收甲烷，但 CER 对 AD 中氢气和甲烷生成的同时增强作用尚未得到广泛研究。本文研究了 CER 对氢气和甲烷顺序回收的影响及其相应的机制。当引入 CER 时，氢气和甲烷的最大产量分别增加了 104.7%和 35.3%，证实了 CER 对氢气和甲烷产生的顺序增强作用。分析有和没有 CER 作用时主要生化成分的变化表明，CER 促进了氢气和甲烷产生阶段的污泥有机溶解、水解和酸化。此外，对污泥固液界面热力学和主要多价金属去除率的变化研究表明，CER 与污泥在产氢阶段的离子交换反应为细菌和有机颗粒之间的有效接触提供了直接驱动力。此外，CER 在甲烷产生阶段的残余效应降低了质量传递的能量障碍，并为这种传递提供了驱动力。进一步分析微生物群落结构和宏基因组学表明，CER 直接驱动了产氢菌（增加 15.1%）和产氢阶段编码酶的关键基因的富集。此外，CER 间接地诱导了产甲烷厌氧菌（如 Methanosaeta：+16.7%，Methanosarcina：+316.5%）的富集；增强了不同底物向甲基辅酶 M 的生物转化；并促进了甲烷产生阶段的乙酰辅酶 A 过程和 CO 还原代谢途径。本研究可为通过顺序回收从 AD 中同时增强氢气和甲烷的产生提供有价值的见解。
