Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing, 100084, China.
Department of Civil and Environmental Engineering, University of Hawai'i at Mānoa, 2500 Campus Rd, Honolulu, HI, 96822, USA.
Microbiome. 2021 Jan 12;9(1):14. doi: 10.1186/s40168-020-00944-4.
The ozonation of biofilters is known to alleviate clogging and pressure drop issues while maintaining removal performances in biofiltration systems treating gaseous volatile organic compounds (VOCs). The effects of ozone on the biofilter microbiome in terms of biodiversity, community structure, metabolic abilities, and dominant taxa correlated with performance remain largely unknown.
This study investigated two biofilters treating high-concentration toluene operating in parallel, with one acting as control and the other exposed to low-dosage (200 mg/m) ozonation. The microbial community diversity, metabolic rates of different carbon sources, functional predictions, and microbial co-occurrence networks of both communities were examined.
Consistently higher biodiversity of over 30% was observed in the microbiome after ozonation, with increased overall metabolic abilities for amino acids and carboxylic acids. The relative abundance of species with reported stress-tolerant and biofilm-forming abilities significantly increased, with a consortium of changes in predicted biological pathways, including shifts in degradation pathways of intermediate compounds, while the correlation of top ASVs and genus with performance indicators showed diversifications in microbiota responsible for toluene degradation. A co-occurrence network of the community showed a decrease in average path distance and average betweenness with ozonation.
Major degrading species highly correlated with performance shifted after ozonation. Increases in microbial biodiversity, coupled with improvements in metabolizing performances of multiple carbon sources including organic acids could explain the consistent performance commonly seen in the ozonation of biofilters despite the decrease in biomass, while avoiding acid buildup in long-term operation. The increased presence of stress-tolerant microbes in the microbiome coupled with the decentralization of the co-occurrence network suggest that ozonation could not only ameliorate clogging issues but also provide a microbiome more robust to loading shock seen in full-scale biofilters. Video abstract.
臭氧化生物过滤器已知可以缓解堵塞和压降问题，同时保持处理气态挥发性有机化合物（VOC）的生物过滤系统的去除性能。臭氧对生物过滤器微生物组的影响，包括生物多样性、群落结构、代谢能力以及与性能相关的优势分类群，在很大程度上仍然未知。
本研究调查了两个平行运行的高浓度甲苯生物过滤器，一个作为对照，另一个暴露于低剂量（200mg/m）臭氧中。检查了两个群落的微生物群落多样性、不同碳源的代谢率、功能预测和微生物共生网络。
臭氧处理后，微生物组的生物多样性始终高出 30%以上，整体对氨基酸和羧酸的代谢能力增强。具有报道的耐应激和生物膜形成能力的物种的相对丰度显著增加，预测生物途径的联合体发生变化，包括中间化合物降解途径的转变，而与性能指标相关的顶级 ASVs 和属的相关性表明，负责甲苯降解的微生物群多样化。群落的共生网络显示，臭氧处理后平均路径距离和平均介数减少。
与性能高度相关的主要降解物种在臭氧处理后发生了变化。微生物生物多样性的增加，加上包括有机酸在内的多种碳源代谢性能的提高，可以解释尽管生物量减少，但臭氧处理生物过滤器的性能仍然一致，同时避免了长期运行中的酸积累。微生物组中耐应激微生物的增加加上共生网络的去中心化表明，臭氧处理不仅可以改善堵塞问题，而且可以为全规模生物过滤器中常见的负载冲击提供更健壮的微生物组。视频摘要。
Zotero 插件
