School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, 430070, China.
School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, PR China.
J Environ Manage. 2023 Oct 15;344:118715. doi: 10.1016/j.jenvman.2023.118715. Epub 2023 Aug 8.
Petrochemical wastewater contains inhibitory compounds such as aromatics that are toxic to microorganisms during biological treatment. The compact and layered structure and the high amount of extracellular polymeric substances (EPS) in aerobic granular sludge (AGS) can contribute to protecting microorganisms from the harsh environment. This study evaluated the changes in the granule properties, pollutants removal, microbial metabolic potential and molecular microbial characteristics of the AGS process for petrochemical wastewater treatment. Granules treating petrochemical wastewater had a higher SVI/SVI value (0.94) than that treating synthetic wastewater. An increase in bioactivity and EPS secretion with higher bio-polymer composition, specifically the functional groups such as hydroxyl, alkoxy and amino in protein, was observed, which promoted biomass aggregation. The granules also had more than 2-fold higher specific oxygen utilization rate. The AGS-SBR process obtained an average COD removal of 93% during petrochemical wastewater treatment and an effluent bCOD of below 1 mg L. No obvious inhibition of nitrification and denitrification activity was observed in the processes attributed to the layered structure of AGS. The average effluent NH-N of 5.0 mg L was obtained and TN removal efficiencies of over 80.0% was achieved. Molecular microbial analysis showed that abundant functional genera Stenotrophomonas and Pseudoxanthomonas contributed to the degradation of aromatics and other petroleum organic pollutants. They were enriched with the variation of group behavior while metabolisms of amino acids and carboxylic acids by the relevant functional genera (e.g., Cytophagia) were significantly inhibited. The enrichment of Flavobacterium and Thermomonas promoted nitrification and denitrification, respectively. This research revealed the rapid start-up, enhanced granule structural strength, high inhibition resistance and considerable performance of AGS-SBR for petrochemical wastewater treatment.
石化废水含有芳香族等抑制化合物，这些化合物在生物处理过程中对微生物有毒。好氧颗粒污泥（AGS）的紧凑分层结构和大量胞外聚合物（EPS）有助于保护微生物免受恶劣环境的影响。本研究评估了石化废水处理中 AGS 工艺的颗粒特性、污染物去除、微生物代谢潜力和分子微生物特征的变化。处理石化废水的颗粒的 SVI/SVI 值（0.94）高于处理合成废水的颗粒。生物活性和 EPS 分泌增加，生物聚合物组成更高，特别是蛋白质中的羟基、烷氧基和氨基等功能基团，促进了生物量的聚集。颗粒的比需氧量也提高了两倍以上。AGS-SBR 工艺在处理石化废水时获得了平均 93%的 COD 去除率，出水 bCOD 低于 1mg/L。由于 AGS 的分层结构，硝化和反硝化活性没有明显受到抑制。过程中平均出水 NH-N 为 5.0mg/L，TN 去除效率超过 80.0%。分子微生物分析表明，丰富的功能属 Stenotrophomonas 和 Pseudoxanthomonas 有助于芳烃和其他石油有机污染物的降解。随着群体行为的变化，它们得到了富集，而相关功能属（如 Cytophagia）的氨基酸和羧酸代谢则受到明显抑制。Flavobacterium 和 Thermomonas 的富集分别促进了硝化和反硝化。本研究揭示了 AGS-SBR 对石化废水处理具有快速启动、增强颗粒结构强度、高抗抑制性和相当的性能。
