厌氧活性污泥产电特性及产电过程微生物群落变化

Electricity production and microbial community change of anaerobic sludge

以厌氧活性污泥为接种液构建微生物燃料电池(MFC),检测了运行第1周期前后电池的理化性质及菌群变化情况。结果表明,MFC启动后产电性能良好,外接1000?电阻时输出电压可达0.62 V,功率密度达1247 mW/m2,内阻为143?,化学需氧量(COD)去除率达63.6%;高通量测序结果显示,MFC菌群与原始接种厌氧活性污泥菌群相比变化较明显,菌群多样性指数降低,优势菌门硬壁菌门(Firmicutes)和变形菌门(Proteobacteria)为产电菌群常见门,与MFC产电能力直接相关的克雷伯氏菌属(Klebsiella)富集并成为优势菌属,相对丰度达16.73%。

The production of methane by anaerobic fermentation is the main treatment mode of organic waste such as wastewater, but subsequent processes of carbon dioxide separation, methane storage and transportation have restricted its application. Microbial fuel cells can directly convert the chemical energy of organic waste into electrical energy, and converting the traditional anaerobic fermentation methanogenesis process of organic waste into electricity production process, which is a greener and more environmentally friendly process and has broad application prospects. In present study, a microbial fuel cell(MFC) with good performance was constructed by using an anaerobicactivated sludge as inoculum. High-throughput sequencing was used to analyze the changes of bacteria and archaea before and after MFC operation. The results showed that when the external 1 000 ? resistor was used, the output voltage reached 0.62 V, the output power reached 1 247 mW/m2, and the internal resistance was 143 ?, the Coulomb efficiency was 9.9%, the COD removal rate of the sludge in anode chamber reached 64% after MFC operation. When the sludge was treated by MFC, only the electron was produced instead of traditional CH4 and H2, thereby avoiding problems such as CO2 separation, CH4 storage and transportation in the methanogenesis process. The composition of archaea was relatively stable, while the bacterial flora changed significantly. Compared with the original anaerobic sludge, the MFC microbial diversity index decreased, while the dominant bacteria group became more obvious. The dominant bacteria Firmicutes and Proteobacteria were accepted as the common electric producing bacteria. Klebsiella, which is directly related to MFC’s ability to produce electricity, is enriched and became a dominant genus with a relative abundance of 16.73%. In addition, Hydrogenophaga is also abundantly enriched, which may be a novel electrogenic microorganism. This study provided theoretical and technical support for the conversion of organic waste into electrical energy through anaerobic treatment.