污泥-秸秆联合厌氧消化体系多环芳烃微生物共代谢降解机制
- The Co-metabolic Degradation Mechanism of Polycyclic Aromatic Hydrocarbons by microorganisms in the Sludge-Straw Combined Anaerobic Digestion System
- 基金项目：中国科学院重点资助项目,中国科学院重大资助项目
- 摘要：本研究采用稳定同位素探针（DNA-SIP）技术，探究了污泥-秸秆联合厌氧消化体系中苯并[a]芘（BaP）的共代谢降解机制。结果表明，该体系提升了厌氧微生物活性，BaP降解从30.2%提升至44.6%。肠杆菌（Enterobacteriales）降解BaP的同时生成H2，促进了氢自养微生物脱氯单胞菌（Dechloromonas）对BaP的降解；生成的NO2-被厌氧氨氧化菌（Candidatus Brocadia）利用，减弱了NO2-对肠杆菌和脱氯单胞菌对BaP降解的抑制；BaP通过开环生成3,4-二羟基菲最终转化为原儿茶酸，另外也可通过逐步开环并甲基化生成1-甲基菲，最终转化为邻苯二甲酸二乙酯。本研究为理解PAHs在污泥-秸秆联合厌氧消化体系中的降解机制提供了新见解，并为PAHs污染治理提供了新思路。
- Abstract：This study investigated the mechanism of co-metabolic degradation of benzo[a]pyrene (BaP) in the anaerobic digestion system combined with sludge and straw through the stable isotope nucleic acid probe (DNA-SIP). The results showed that the activity of anaerobic microorganisms were improved and the degradation efficiency of BaP increased from 30.2% to 44.6%. The Enterobacteriales could degrade BaP accompanied by the production of H2, which promoted the degradation of BaP by Dechloromonas. The NO2- produced by Dechloromonas was utilized by Candidatus Brocadia, which weakened its inhibitory on BaP degradation. BaP can be transformed to protocatechuic acid and finally 3,4-dihydroxyphenanthrene by ring-opening , as well as to diethyl phthalate through the intermediate of 1-methylphenanthrene with the stepwise ring-opening and methylation. The findings provide new insights into the degradation mechanism of PAHs in sludge-straw combined anaerobic digestion system, and new ideas for PAHs pollution control.
