Evaluating groundwater ecosystem dynamics in response to post in-situ remediation of mixed chlorinated volatile organic compounds (CVOCs): An insight into microbial community resilience, adaptability, and metabolic functionality for sustainable remediation and ecosystem restoration

• Published in: The Science of the total environment Vol. 920; p. 170874
• Main Authors: Huang, Shih-Wei, Hussain, Bashir, Chen, Jung-Sheng, Asif, Aslia, Hsu, Bing-Mu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.04.2024
• Subjects: Groundwater - chemistry; Groundwater contamination; Groundwater ecosystem function; Groundwater microbial community; In-situ remediation; Microbiota; Mixed chlorinated volatile organic compounds (CVOCs); Nitrogen; Resilience, Psychological; Volatile Organic Compounds; Water Pollutants, Chemical - analysis; Groundwater contamination; Groundwater microbial community; In-situ remediation; Groundwater ecosystem function; Mixed chlorinated volatile organic compounds (CVOCs)
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.170874

The in-situ remediation of groundwater contaminated with mixed chlorinated volatile organic compounds (CVOCs) has become a significant global research interest. However, limited attention has been given in understanding the effects of these remediation efforts on the groundwater microbial communities, which are vital for maintaining ecosystem health through their involvement in biogeochemical cycles. Hence, this study aimed to provide valuable insights into the impacts of in-situ remediation methods on groundwater microbial communities and ecosystem functionality, employing high-throughput sequencing coupled with functional and physiological assays. The results showed that both bioremediation and chemical remediation methods adversely affected microbial diversity and abundance compared to non-polluted sites. Certain taxa such as Pseudomonas, Acinetobacter, and Vogesella were sensitive to these remediation methods, while Aquabacterium exhibited greater adaptability. Functional annotation unveiled the beneficial impact of bioremediation on the sulfur cycle and specific taxa such as Cellvibrio, Massilia, Algoriphagus, and Flavobacterium which showed a significant positive relationship with dark oxidation of sulfur compounds. In contrast, chemical remediation showed adverse impacts on the nitrogen cycle with a reduced abundance of nitrogen and nitrate respiration along with a reduced utilization of amines (nitrogen rich substrate). The findings of this study offer valuable insights into the potential impacts of in-situ remediation methods on groundwater microbial communities and ecosystem functionality, emphasizing the need for meticulous consideration to ensure the implementation of effective and sustainable remediation strategies that safeguard ecosystem health and function. [Display omitted] •In-situ remediation significantly reduced microbial diversity in groundwater.•Pseudomonas, Acinetobacter, and Vogesella were sensitive to in-situ remediation.•Aquabacterium showed greater adaptability and resilience to in-situ remediation.•Bioremediation positively influenced the sulfur cycle in groundwater ecosystem.•Chemical remediation negatively influenced the nitrogen cycle in groundwater ecosystem.