【摘要】 人工湿地深度脱氮过程中碳源不足会导致反硝化效率较低,可通过添加缓释碳源来为反硝化提供额外电子供体。现针对几种农林废弃物进行释碳性能评估,并研究了微电解与电解对碳源释碳与反硝化的强化效果。结果表明:香茅草干的释碳效果最佳,复合二级动力学方程,饱和释碳量为86.8 mg/(g·L);微电解与电解作用不仅可以促进香茅草干碳源释放,对反硝化效果也有提升,释碳总量可提高约49.5%和56.6%,在稳定期反硝化率可提高约33.8%和24.5%;释碳三维荧光表明微电解可以促进碳源中芳香蛋白类物质以及富里酸类物质的释放,电解可以促进碳源中陆源类腐殖质的释放;碳源表面FTIR光谱图表明有较多烃类与醛类物质的释放,其中微电解组中富里酸中的醌基能够提高碳源的电子传递效率;对碳源进行扫描电镜(SEM)观察发现电化学作用使得纤维素骨架发生溶蚀,表面变得光滑;香茅草干表面可作为微生物生长附着的载体,其中拟杆菌门和变形菌门为优势菌门,并且电解作用提高了厚壁菌门的相对丰度,在强化反硝化作用的同时也促进了纤维素的降解。更多还原

【Abstract】 During deep denitrification in constructed wetlands, insufficient carbon sources can lead to low denitrification efficiency. This can be solved by adding slow-release carbon sources to provide additional electron donors. Now this study carried out the carbon release optimization for several straw knots, and two electrochemical effects( micro-electrolysis and electrolysis) were investigated to enhance carbon release and denitrification from carbon sources. Results showed that cymbopogon citratus which composites secondary kinetic equation had the best carbon release, and its saturated carbon release reaches 86. 8mg/(g·L); micro-electrolysis and electrolysis can not only promote the release of cymbopogon citratus, but also improve the denitrification effect, the total carbon release can be increased by about 49. 5% and 56. 6%, the denitrification rate can be increased by about 33. 8% and 24. 5% in the stable period; the Excitation-Emission-Matrix Spectra of carbon release indicates that micro-electrolysis can promote the release of aromatic proteins and fulvic acids from carbon sources, electrolysis can promote the release of terrestrial humic substances from carbon sources; the FTIR spectrogram of carbon source surface indicates more hydrocarbons and aldehydes release, and the quinone group in fulvic acid from micro-electrolysis group can improve the electron transfer efficiency of carbon source; the surface of cymbopogon citratus was observed by scanning electron microscope( SEM), which revealed that electrochemical actions caused the cellulose skeleton to dissolve and smoothed the surface; at the same time, the surface of cymbopogon citratus can be used as a carrier for microbial growth, among which Bacteroidota and Proteobacteria are the dominant phyla. The electrolysis increases the relative abundance of Firmicutes, which strengthens denitrification as well as cellulose degradation.更多还原