地下水被苯和甲苯污染是一个普遍的问题,对生态系统和人类健康构成威胁。在硫酸盐还原条件下去除苯和甲苯是众所周知的,但在这个过程中细菌群落如何变化仍不清楚。本研究旨在评估硫酸盐还原条件下苯和甲苯生物降解过程中细菌群落结构的变化。在这项研究中,从现场收集被苯和甲苯污染的地下水,并用于构建三个人工样品:对照(苯50mg/L,甲苯1.24mg/L,硫酸盐470mg/L,和HgCl2250毫克/升),S1(苯50mg/L,甲苯1.24mg/L,硫酸盐470毫克/升),和S2(苯100毫克/升,甲苯2.5mg/L,硫酸盐940mg/L)。污染物(苯和甲苯),地球化学参数(硫酸盐,ORP,和pH),随着时间的推移,监测人工样品中的细菌群落结构。到本研究结束时(第90天),在S1和S2人工样品中可以消除大约99%的苯和96%的甲苯,而在对照人工样品中,由于微生物失活,污染物水平保持不变。在S1和S2人工样品中,细菌群落的丰富度最初降低,但随后随时间增加。在硫酸盐还原条件下,苯和甲苯降解的关键参与者被确定为假单胞菌,Janthinobacterium,Novoshingoum,葡萄球菌,和缓生根瘤菌.研究结果可为苯和甲苯污染场地的修复和风险管理策略提供科学依据。
Groundwater contaminated by benzene and
toluene is a common issue, posing a threat to the ecosystems and human health. The removal of benzene and
toluene under sulfate-reducing condition is well known, but how the bacterial community shifts during this process remains unclear. This study aims to evaluate the shift in bacterial community structure during the biodegradation of benzene and toluene under sulfate-reducing condition. In this study, groundwater contaminated with benzene and toluene were collected from the field and used to construct three artificial samples: Control (benzene 50 mg/L,
toluene 1.24 mg/L, sulfate 470 mg/L, and HgCl2 250 mg/L), S1 (benzene 50 mg/L,
toluene 1.24 mg/L, sulfate 470 mg/L), and S2 (benzene 100 mg/L,
toluene 2.5 mg/L, sulfate 940 mg/L). The contaminants (benzene and toluene), geochemical parameters (sulfate, ORP, and pH), and bacterial community structure in the artificial samples were monitored over time. By the end of this study (day 90), approximately 99% of benzene and 96% of toluene could be eliminated in both S1 and S2 artificial samples, while in the Control artificial sample the contaminant levels remained unchanged due to microbial inactivation. The richness of bacterial communities initially decreased but subsequently increased over time in both S1 and S2 artificial samples. Under sulfate-reducing condition, key players in benzene and toluene degradation were identified as Pseudomonas, Janthinobacterium, Novosphingobium, Staphylococcus, and Bradyrhizobium. The results could provide scientific basis for remediation and risk management strategies at the benzene and toluene contaminated sites.