Abstract:

Aerobic biodegradation was employed to degrade Diethylene glycol monobutyl ether(DGBE), and the degradation effect was investigated by gradually increasing the influent DGBE concentration. Activated sludge samples were collected for high-throughput sequencing analysis before, during the stable period, and at high concentration acclimation, respectively. The potential degradation pathways of DGBE were inferred based on the identification of intermediate products. The experimental results indicated that when the DGBE concentration was below 832.85 mg/L, the removal rates of DGBE and COD could achieve over 99% and 93%, respectively, while a further increase in influent concentration led to a decline in removal efficiency. The richness and diversity of the microbial community in the activated sludge were significantly reduced after DGBE acclimation. During the stable acclimation period, the dominant phylum was Proteobacteria(78.59%), with the dominant genera of Cupriavidus(42.44%) and Rhodanobacter(20.02%). In the high concentration acclimation period, Actinobacteriota(51.15%) surpassed Proteobacteria(43.41%) as the most abundant phylum, and Nakamurella(49.81%) was the primary dominant genus. The main intermediate products of DGBE were detected, as butyl glycol, butyraldehyde, and vinyl butyl ether, suggesting possible degradation pathways as the ω-oxidation and β-oxidation pathway, and the ether bond cleavage degradation pathway due to sub-terminal oxidation.

Key words: diethylene glycol monobutyl ether, aerobic degradation, microbial community structure, degradation pathways

摘要：

采用好氧生物法对二乙二醇丁醚（DGBE）进行降解，过程中逐步提升进水DGBE浓度考察其降解效果。分别在驯化前、驯化稳定期和高浓度驯化期获取活性污泥样品进行高通量测序分析，并基于降解中间产物推测出DGBE可能存在的降解途径。实验结果表明：DGBE质量浓度低于832.85 mg/L时，DGBE和COD的去除率分别可达到99%和93%以上，继续提升进水浓度则去除率出现下降趋势。DGBE驯化后活性污泥微生物的丰富度和多样性大幅降低，驯化稳定期的优势菌门为Proteobacteria（78.59%），优势菌属为Cupriavidus（42.44%）和Rhodanobacter（20.02%），高浓度驯化期Actinobacteriota（51.15%）超越Proteobacteria（43.41%）成为丰度最高的菌门，Nakamurella（49.81%）为主要优势菌属。检测到DGBE的主要中间产物包括乙二醇丁醚、丁醛和乙烯基正丁醚，分析其可能的降解途径为ω-β-氧化降解途径和次末端氧化导致的醚键断裂降解途径。

关键词: 二乙二醇丁醚, 好氧降解, 微生物群落结构, 降解途径

CLC Number: 

• X703.1