中文摘要：

传统厌氧消化基质转化慢，甲烷产率和能量回收效率较低．本研究模拟厌氧酸化产生的短链脂肪酸（SCFAs）废水，在批式条件下，利用单室无膜微生物电解池辅助厌氧消化（MEC—AD）产甲烷，考察不同外加电压（0.4V、0.6V、0．8V）对底物降解、甲烷产生和能量回收效率的影响．结果表明，进水化学需氧量（COD）浓度约为7000mg／L时，COD的平均去除负荷由AD的（3．34±0．09）kgm-3d-1提高到MEc．AD的（6．864-0．04）kgm-3d-1（外加0．8V），增加了1．06倍．外加电压与脂肪酸组分的降解呈正相关，即随着外加电压的升高，底物各SCFA降解速率加快，此时相应的甲烷含量、产量明显提高．当外加电压为0．8V时，混合脂肪酸中乙酸、丙酸及丁酸的降解速度较AD分别提高了98．25％、107．14％、54．21％，甲烷的含量达90．11％；甲烷的产率为2．63LL-1d-1，较AD提高了157．84％．以基质化学能、电能和产生的甲烷来计算总能量回收效率，其中AD为73．51％；加电0．4V、0．6V、0．8V时分别为93．44％、88．99％、93．41％．综合脂肪酸降解、甲烷产生及能量回收情况，确定外加0．8V为最优条件．循环伏安扫描分析发现，与AD相比，MEC-AD在-0．3V处存在明显产甲烷还原峰．高通量测序结果显示，MEC-AD中阳极优势菌群为Methanosaetasp．和Geobacter sp．，其相对丰度比分别为36．43％和13．35％；而AD中相应比例仅为24．46％和0．99％．由此可知MEC—AD中可能存在直接的种间电子传递（DIET）产甲烷途径，该途径是甲烷含量和产量提升的重要原因．综上，以微生物电解池辅助厌氧消化能有效促进底物降解，且获得高纯度、高产量的甲烷，具有良好的应用前景．（图4表1参28）

英文摘要：

This study aimed to accelerate substrate transformation and improve the production rate and energy recovery rate of methane. We used a single-chamber microbial electrolysis cell （MEC-AD） with stainless steel cathode to treat the artificial short-chain fatty acids （SCFAs） wastewater for methane production. The effects of external applied voltage （0.4 V, 0.6 V, 0.8 V） on substrates degradation, methane production and energy recovery efficiency were studied by comparing with the traditional anaerobic digestor （AD）. The results showed that MEC-AD could effectively promote substrates degradation and methane generation. When the influent COD concentration was about 7000mg.L-1, the average organic matter removal load （ORL） was increased from 3.34 ± 0.09 kg m-3 d-1 of AD to 6.86 ± 0.04 kg m-3 d-1 of MEC-AD （applied 0.8 V）. It was found that the degradation rate of each SCFA, methane content and production were obviously increased with the applied voltage. Especially under the applied voltage of 0.8 V, the degradation rate of acetate, propionate and butyrate increased by 98.25%, 107.14% and 54.21% respectively; the methane content was up to 90.11%; and the methane production rate was 2.63 L L-1 d-1, which was 157.84% higher than AD. Moreover, the total energy recovery efficiency was 73.51% （AD）, 93.44% （0.4 V）, 88.99% （0.6 V） and 93.41% （0.8 V） respectively. Considering the degradation of SCFAs, methane production and energy recovery efficiency, the optimal condition in this work was under 0.8 V. Further cyclic voltammetry analysis exhibited a reduction peak at -0.3 V in MEC-AD, which represented a characteristic peak of methanogenesis. High-throughput sequencing analysis revealed that the anodic dominant population was Methanosaeta sp. and Geobacter sp. in MEC-AD, with relative abundance of 36.43~,/0 and 13.35% respectively. In AD, the corresponding proportion was only 24.46% and 0.99%. It might be deduced that there is a direct interspecies electron transfer （DIET） pathway i