Tetracycline (TC), a widely used antibiotic, poses a significant environmental threat due to its persistence in aquatic ecosystems and its contribution to antibiotic resistance. Adsorption has emerged as a cost-effective and efficient method for removing TC from contaminated water. A recent bibliometric review by Ramesh Vinayagam, Thivaharan Varadavenkatesan, and Raja Selvaraj, published in Results in Engineering, analyzes 567 articles from 2015 to 2025 to understand trends, challenges, and future directions in this critical research area.

The analysis, using tools like VOSviewer and Bibliometrix, revealed a significant upward trend in TC adsorption research. Annual publications peaked at 111 articles in 2024, with a total of 4,854 citations in the same year. The field shows a robust culture of collaboration, with an average of 6.64 co-authors per document and 21.34% international co-authorship. Overall, the average document has an impressive 34.05 citations, indicating the impactful nature of these publications. Geographically, China dominates the research output with 348 publications and 13,376 citations, highlighting its central and prolific role. The United States and India are also key players, with 35 and 39 publications, respectively, demonstrating strong collaborative networks. Significant institutional contributions come from Hunan University and Anhui Agricultural University.

The research in TC adsorption is highly interdisciplinary, spanning engineering (29.5%), chemistry (28.7%), environmental sciences & ecology (23.8%), materials science (9.4%), and water resources (8.6%). This multifaceted approach is largely driven by the United Nations Sustainable Development Goal (SDG) 6: Clean Water and Sanitation, which accounts for 85.9% of the research focus. SDG 3: Good Health and Well-being, with 10.9% of the focus, also plays a notable role.

Keyword analysis reveals trending materials and mechanisms. Magnetic biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More and metal-organic frameworks (MOFs) are identified as prominent and emerging adsorbents. While activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More and traditional biochar remain relevant, the shift towards modified forms like magnetic biochar indicates a drive for improved material properties and recovery methods. Research also delves into fundamental aspects such as adsorption mechanisms and kinetics.

Despite significant progress, several research gaps remain. The review highlights the limited use of computational modeling, such as Density Functional Theory (DFT) studies, and the absence of statistical physics models in the literature, which could offer deeper insights into adsorption mechanisms. There is also a notable lack of emphasis on sustainable and cost-effective regeneration strategies for advanced materials like MOFs and nanocomposites. Furthermore, a significant gap exists in translational research, with only 20 studies focusing on continuous systems using packed/fixed bed columns, which are crucial for industrial applications. The integration of Artificial Intelligence/Machine Learning (AI/ML) in TC adsorption research is also conspicuously absent.

The findings underscore the need for a shift from material discovery to system-level integration and performance optimization. Future research should prioritize hybrid technologies, pilot-scale studies, and AI-assisted material screening to bridge the gap between laboratory findings and real-world applications. Increased international collaboration and standardized experimental reporting are also crucial to accelerate innovation and comparability across studies. This comprehensive review serves as a roadmap to strategically address the growing challenge of tetracycline pollution in water systems.

Source: Vinayagam, R., Varadavenkatesan, T., & Selvaraj, R. (2025). Tetracycline Adsorption Research (2015-2025): A Bibliometric Analysis of Trends, Challenges, and Future Directions. Results in Engineering.