氮掺杂污泥炭载纳米Fe3O4耦合厌氧共代谢去除难降解有机物的强化机理

Prevention and control of refractory organic pollutants have attracted more and more attentions which have posed a serious threat to the environment safety. Cometabolic, as the main metabolic mechanism of anaerobic biodegradation of refractory organic matters, has the huge development potential, however, lack of coordinated regulation causes low of growth substrates selection and energy utilization that have become a bottleneck of its theory development and practical application. In this study, anaerobic cometabolic biodegradation of refractory organic matter-2,4,6-trichlorophenol (2,4,6-TCP) is selected as object of study, and metabolic pathways, microbial physiological and biochemical properties and community structure dynamics, quorum sensing, etc. will be directly investigated. The influence mechanism of different growth substrates on anaerobic cometabolic degradation of 2,4,6-TCP will be determined. Meanwhile, sewage sludge of biological wastewater treatment plant was converted into sewage sludge activated carbon with the modification of nitrogen doping (N-SAC) which supported nanoscaled Fe3O4 (Fe3O4MNPs/N-SAC) as cheap biological carrier with catalytic function, and the in-situ strengthening role of which and key regulatory factors on anaerobic sludge granulation will be ascertained. Finally, strengthening mechanism of Fe3O4MNPs/N-SAC coupled anaerobic cometabolic removal refractory organic matters and its practical application will be revealed, and then an innovative strategy of energy regulation coupled with bioaugmentation to cooperative improve anaerobic cometabolic will be proposed which should be beneficial to promoting the development of anaerobic cometabolic theory and expanding the application scope, furthermore, the novel refractory wastewater treatment technology with efficient and economical advantages will be established.

难降解有机污染物严重危害环境安全并成为污染防治的关键。共代谢作为厌氧生物处理难降解有机物的主要代谢机制，因缺乏有效的协同调控导致生长基质选择限制与能量利用低等问题成为其理论发展与实际应用的瓶颈。本项目以难降解有机物-2,4,6-三氯酚的厌氧共代谢过程为对象，通过物质代谢途径、微生物生理生化与群落结构特征及群感效应等方面系统研究，阐明不同生长基质对厌氧共代谢性能的影响机制；以废物剩余污泥研发氮掺杂污泥炭载纳米Fe3O4（Fe3O4MNPs/N-SAC）作为兼具催化功能的廉价生物载体，探明其原位强化厌氧颗粒污泥形成的机理及关键调控因子，揭示Fe3O4MNPs/N-SAC耦合厌氧共代谢去除难降解有机物的强化机理及实际应用性，创新性提出能量调控耦合生物强化协同提升厌氧共代谢性能的新模式，促进共代谢理论的发展和拓展应用范围，为构建经济高效的新型难降解废水厌氧生物处理技术奠定基础。

共代谢作为厌氧生物处理难降解有机物的主要代谢机制，因缺乏有效的协同调控手段导致基质选择限制与能量利用低等问题成为其理论发展与实际应用的瓶颈。本项目以难降解有机物2,4,6-三氯酚厌氧降解为对象，分析不同生长基质对其共代谢性能的影响，以废物剩余污泥研发氮掺杂污泥炭载纳米Fe3O4（Fe3O4/N-SBAC），揭示Fe3O4/N-SBAC耦合厌氧共代谢去除难降解有机物的强化机理及应用性。研究结果表明，不同类型的基质对2,4,6-三氯酚厌氧降解具有显著影响，葡萄糖与间苯二酚均可以促进2,4,6-三氯酚降解，葡萄糖还提高底物的矿化，而喹啉则具有抑制性。葡萄糖基质不同投加方式均强化了2,4,6-三氯酚降解性，增加了关键酶F420和胞外聚合物（EPS）含量，提高了电子传递体系活性（ETS）和CH4产生，且递减式投加提升程度最为显著。优化了氮掺杂污泥炭的制备参数，通过XPS、XRD、FTIR、SEM、BET等对Fe3O4/N-SBAC进行表征，明确其理化性质。Fe3O4/N-SBAC耦合共代谢显著强化了2,4,6-三氯酚厌氧降解性能，2,4,6-三氯酚和COD去除与甲烷产量及转化率均呈增加趋势，并减少了挥发酸积累，同时，Fe3O4/N-SBAC提高了污泥的SMA、关键酶活性、ETS和EPS，促进了污泥颗粒化，增加了微生物丰度和多样性，Fe3O4/N-SBAC富集的Geobacter与Methanothrix和Methanosarcina进行直接种间电子传递（DIET），提高了污染物去除与产甲烷效率。进而，以煤化工废水作为高酚难降解废水，Fe3O4/N-SBAC显著提高了厌氧工艺对废水COD去除和产甲烷，处理出水具有更好的可生化性和更低的生物毒性，同时提高了EPS和辅酶F420浓度，此外，Fe3O4/N-SBAC促进厌氧污泥颗粒化，具有较高的粒径、较多的群感种间信号分子和较低的扩散信号因子，群落分析表明，Fe3O4/N-SBAC促进了Geobacter和Methanothrix富集，并通过其作为电子传递载体形成了DIET，促进煤化工废水的污染物厌氧产甲烷效率。同时，该厌氧工艺具有较高的稳定性，适于工业化应用。.本研究提出了共代谢耦合Fe3O4/N-SBAC协同强化厌氧降解有机污染物的新模式，促进了共代谢和DIET理论的发展，对构建经济高效的新型厌氧工艺具有重要的理论意义。