Screening of hazardous groundwater pollutants responsible for microbial ecological consequences by integrated nontargeted analysis and high-throughput sequencing technologies

Organic contaminants, especially hydrophobic organic contaminants (HOCs), pose potential ecological threats even at environmental concentrations. Characterization of HOC profiles and identification of key environmental stressors are vital but still challenging in groundwater quality management. In this study, a strategy for identifying the key environmental stressors among HOCs in groundwater based on integrated chemical monitoring technologies and microbial ecology analysis methods was proposed and applied to typical groundwater samples. Specifically, the characteristics of HOCs were systematically analyzed based on nontargeted and targeted approaches, and microbial community assembly and specific biomarker analysis were combined to determine the major ecological processes and key environmental stressors. The results showed that a total of 234 HOCs were detected in groundwater collected from Tongzhou, Beijing; among them, phthalate esters (PAEs) were screened out as key environmental stressors, considering that they made relatively higher microbial ecology contributions. Furthermore, their influences on the structure and function of the groundwater microbial community were evaluated by adopting high-throughput sequencing and bioinformatics analysis technologies. These findings confirmed PAEs as vital determinants driving microbial assembly, shifting community structure, and regulating community function in groundwater; in addition, the findings validated the feasibility and suitability of the proposed strategy.