微生物燃料电池降解焦化废水过程研究

焦化废水生化处理流程复杂，污染物降解过程尚不明确，构建无膜空气阴极焦化废水微生物燃料电池，利用循环伏安法、红外分析、微生物群落结构等分析考察了焦化废水的降解过程中，各类有机物含量变化、官能团的变化、有机物异步降解次序及优势菌种的演替.焦化废水中含硫无机物被优先降解，酚类降解次之，含氮污染物历经好氧硝化与厌氧反硝化降解过程，但落后于前者；长链烷烃类降解缓慢；生物群落结构与底物中有机物种类密切相关，初期Desulfurella优先氧化含硫污染物、Flavobacterium降解酚类次之、Nitrospirae氧化降解NH₄⁺-N较为缓慢，随时间延长Alcaligenes、Thiobacillus演变为优势菌落，实现了酚类的降解及NO₃^-的反硝化降解；电池输出电压为470.9mV，最高输出功率密度达12.5mW/cm²，COD、T_phenols、T_surful、TN、NH₄⁺-N的降解分别为85.8%、83.3%、87.5%、43.8%、89.9%.利用微生物燃料电池技术处理焦化废水，一步实现水质净化及能量回收，为废水生物处理控制提供理论和实践参考.

The degradation process of coking wastewater by microbial fuel cells

The current biological process for coking wastewater treatment requires the combination of several units with different methods. In addition, the mechanism of how the pollutants would be degraded along the whole plant is still not yet defined. All these consequently prevent targeted optimization to be conducted. To tackle these problems, a membrane-less air-cathode microbial fuel cell was constructed in this paper. Cyclic voltammetry and polarization were carried out to characterize the electrochemical performance of MFCs, while infrared spectroscopy, colorimetric methods and pyrosequencing were applied to trace the changes of chemicals and microbial communities in the reactor during the batch. The results revealed that sulfur-containing inorganic compounds in coking wastewater were degraded at the first, followed by the degradation of phenols. After that, nitrogen-containing pollutants were then removed through a combined pathway of aerobic nitrification and anaerobic denitrification. The degradation of long chain alkanes happened at the later phase of the batch. In addition, it was found that the microbial community structure was highly dependent on the available nutrients presented in the liquid phase. Desulfurella and Flavobacterium were dominant in the community in the early stage to perform aerobic decomposition of sulfurous and phenol pollutants, which would be latterly taken over by Nitrospitrae, Alcaligenes and Thiobacillus for nitrification and denitrification. The maximum power density of the MFC achieved was 12.5mW/cm², of which the cell voltage was 470.9mV. The total removal efficiencies of COD, T_Phenols, T_sulfur, TN and NH₄⁺-N were 85.8%, 83.3%, 87.5%, 43.8% and 89.9%, respectively. All these data demonstrated the feasibility of a one-step process for coking wastewater treatment using microbial fuel cell.