Key Takeaways & Executive Findings
- •• • Bibliometric analysis of 441 papers (2010–2024) shows a rising trend, with three distinct research phases: basic methods (2010–2016), mechanistic exploration (2017–2019), and process optimization (2020–2024). • • Temperature was identified as the most critical environmental factor influencing microbial Cr(VI) remediation efficiency, based on correlation and principal component analysis. • • Biological adsorption and reduction are the dominant mechanisms; specific strains such as Shewanella putrefaciens CN32 and Pannonibacter phragmitetus BB exhibit high Cr(VI) removal efficiencies under optimized conditions. • • Future research directions include microbial community synergy, nanomaterial integration, and environmental condition optimization to improve remediation performance.
Abstract
Microbial remediation is a widely used technology for treating chromium pollution in groundwater. This study conducted a bibliometric analysis of 441 papers from the Web of Science Core Collection (2010–2024) using CiteSpace, VOSviewer, and Pajek. The publication trend increased over the period, with three developmental stages identified: early (2010–2016) focusing on basic treatment methods, intermediate (2017–2019) on intrinsic mechanisms, and recent (2020–2024) on process optimization. Biological adsorption and reduction were identified as the primary mechanisms. Correlation and principal component analyses of environmental factors (temperature, pH, initial Cr concentration, reaction time) revealed temperature as the key factor affecting remediation efficiency. The removal efficiencies and mechanisms of various dominant bacterial strains were summarized to guide strain selection. Future research should focus on microbial community synergy, nanomaterial integration, and environmental optimization to enhance remediation efficiency.
1. Introduction
Chromium pollution in groundwater poses a severe threat to ecosystems and human health due to the high toxicity, solubility, and carcinogenicity of Cr(VI). Conventional physicochemical remediation methods, such as chemical precipitation and ion exchange, are often costly, energy-intensive, and may generate secondary waste. These limitations have driven the exploration of microbial remediation as a sustainable alternative, leveraging the natural ability of microorganisms to reduce Cr(VI) to less toxic Cr(III). However, the practical application of microbial remediation has been hindered by inconsistent performance under field conditions, largely due to a lack of systematic understanding of the underlying mechanisms and the influence of key environmental factors.
This study addresses this bottleneck by conducting a comprehensive bibliometric analysis of 441 research papers from 2010 to 2024, identifying research hotspots and trends. Through correlation and principal component analysis, the study pinpoints temperature as the dominant environmental factor controlling remediation efficiency, providing a quantitative basis for process optimization. By summarizing the removal efficiencies and mechanisms of various dominant bacterial strains, this work offers actionable guidance for strain selection and operational parameter tuning, thereby bridging the gap between laboratory research and field-scale implementation.
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YANG Yanmei, HE Wanzhuang, LIU Quanli, DANG Qiuling, SU Jing, LIU Yue (2026). Microbial Remediation Technology for Chromium Pollution in Groundwater: Research Hotspots, Mechanisms, and Environmental Factor Analysis. Journal of Environmental Engineering Technology. https://doi.org/10.13205/j.hjgc.202608024
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Frequently Asked Questions
What is the most critical environmental factor affecting microbial Cr(VI) remediation efficiency, and how was it determined?
Temperature was identified as the key factor through correlation analysis and principal component analysis of four environmental factors (temperature, pH, initial Cr concentration, reaction time). The analysis revealed that temperature had the strongest influence on remediation efficiency, likely due to its impact on microbial metabolic activity and enzyme kinetics.
Which bacterial strains have demonstrated high Cr(VI) removal efficiency, and what are their mechanisms?
Strains such as Shewanella putrefaciens CN32 and Pannonibacter phragmitetus BB exhibit high Cr(VI) removal via extracellular reduction and biosorption. For instance, S. putrefaciens CN32 showed enhanced reduction when functionalized biochar was used, while P. phragmitetus BB employs multi-omics responses to detoxify Cr(VI). Removal efficiencies vary with conditions but can exceed 90% under optimized temperature and pH.
What are the main mechanisms of microbial Cr(VI) remediation identified in this study?
The study identified biological adsorption and biological reduction as the primary mechanisms. Adsorption involves binding of Cr(VI) to microbial cell surfaces or extracellular polymers, while reduction converts Cr(VI) to Cr(III) via enzymatic or non-enzymatic pathways, often involving chromate reductase enzymes.
How can the findings of this bibliometric analysis guide future research and practical applications?
The analysis highlights the need for research on microbial community synergy, nanomaterial integration, and environmental optimization. For practical applications, selecting strains with high efficiency under site-specific temperature and pH conditions is crucial. The study provides a framework for prioritizing these factors to enhance remediation performance.
What are the limitations of current microbial remediation technologies for groundwater chromium pollution?
Current limitations include sensitivity to environmental conditions (e.g., temperature, pH), competition with native microorganisms, and the need for nutrient supplementation. Additionally, scale-up from laboratory to field remains challenging due to heterogeneity in subsurface environments. The study emphasizes the importance of optimizing environmental conditions and exploring synergistic microbial communities to overcome these barriers.
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