College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China; School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, PR China.
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
J Environ Manage. 2022 Nov 15;322:116140. doi: 10.1016/j.jenvman.2022.116140. Epub 2022 Sep 5.
Extensive presence of aromatic organic compounds (AOCs) is a major course for the non-biodegradability of coking wastewater (COW). In-depth understanding of bio-degradation of AOCs is crucial for optimizing the design and operation of COW biological treatment systems in practical applications. Herein, the behavior and fate of AOCs were explored in a lab-scale step-feed three-stage integrated A/O biofilter (SFTIAOB) treating synthetic COW. Long-term operation demonstrated that COD, phenol, indole, quinoline and pyridine could be simultaneously removed. Phenol and indole were chiefly removed by anoxic zones, while quinoline and pyridine removal occurred in both anoxic and aerobic zones. Ultraviolet-visible spectrum observed that initial carboxylation and subsequent ring cracking and mineralization. Infrared spectroscopy also confirmed that key functional groups were cracked and produced during AOCs bio-degradation. Three-dimensional fluorescence spectrum indicated that significant transformation and elimination of tryptophan and humic acid with high molecular weight. Ring cleavage, distinct degradation and even complete mineralization of complex AOCs were further verified by gas chromatography-mass spectrometry. Moreover, functional degrading bacteria and aromatic ring-cleavage enzymes was successfully identified. Finally, AOCs biodegradation mechanisms by alternating anoxic and aerobic treatment was unraveled. This research provides thorough insights on AOCs biodegradation using a step-feed multi-stage alternating anoxic/oxic COW treatment process.
芳香族有机化合物（AOCs）的广泛存在是焦化废水（COW）不易生物降解的主要原因。深入了解 AOCs 的生物降解对于优化 COW 生物处理系统的设计和运行具有重要意义。本研究采用实验室规模的分步进料三段式集成 A/O 生物滤池（SFTIAOB）处理模拟 COW，探讨了 AOCs 的行为和归宿。长期运行结果表明，该系统可同时去除 COD、苯酚、吲哚、喹啉和吡啶。其中，缺氧区主要去除苯酚和吲哚，而喹啉和吡啶的去除则发生在缺氧和有氧区。紫外可见光谱观察到初始的羧化作用和随后的环开裂及矿化作用。红外光谱也证实了在 AOCs 生物降解过程中关键官能团的断裂和产生。三维荧光光谱表明，具有高分子量的色氨酸和腐殖酸发生了显著的转化和消除。气相色谱-质谱联用技术进一步验证了复杂 AOCs 的开环、明显降解甚至完全矿化。此外，成功鉴定出具有功能的降解菌和芳香环裂解酶。最后，揭示了交替缺氧/好氧处理的 AOCs 生物降解机制。本研究为分步进料多段交替缺氧/好氧 COW 处理工艺中 AOCs 的生物降解提供了全面的认识。
