Bicarbonate (HCO₃⁻) has been extensively researched as a buffer in anaerobic digestion. The effect of HCO₃⁻ concentration on syntrophic butyrate oxidation process was evaluated by batch culturing of anaerobic activated sludge, and the mechanism was further revealed by the changes of Gibbs free energy (ΔG) and the interspecies transfers of electron and proton. The results showed that butyrate degradation rate was enhanced by 32.07% when the supplement of HCO₃⁻ increased from 0 to 0.20 mol/L. However, methane production and acetate degradation were strongly inhibited by HCO₃⁻ more than 0.10 mol/L. More function of HCO₃⁻ was found as 1) decreasing the ΔG of syntrophic methanogenesis of butyrate while increasing the ΔG of methanogenesis of acetate, 2) enriching M. harundinacea and M. concilii, 3) increasing the diffusion rate of protons between the syntrophic consortia. This work would increase the anaerobic digestion efficiency by enhancing the interaction of the syntrophic consortia.

碳酸氢盐（HCO ₃ ^- ）已被广泛地研究作为厌氧消化的缓冲液。HCO的效果₃ ^-浓度对互养丁酸氧化过程是由厌氧活性污泥的分批培养进行评价，其作用机制是由吉布斯自由能的变化（Δ进一步揭示ģ）以及电子和质子的种间转移。结果表明，丁酸盐降解率是由32.07％提高时HCO的补充₃ ^-从0增加到0.20摩尔/ L。但是，甲烷产生和乙酸降解HCO被强烈抑制₃ ^-超过0.10摩尔/ L。HCO _3的更多功能^-被发现为1）降低Δ ģ丁酸的互养甲烷的同时增加了Δ ģ乙酸的产甲烷，2）富集M. harundinacea和M. concilii，3）增加互养财团之间的质子的扩散速率。这项工作将通过增强同养性联合体的相互作用来提高厌氧消化效率。