In the ever-evolving field of geosciences and environmental engineering, the interactions among physical, chemical, and biological processes remain at the forefront of research aimed at sustainable environmental management and innovative material development. A groundbreaking comprehensive review published in Environmental Earth Sciences in 2025 has brought to light the intricate coupling of thermal, hydraulic, mechanical, chemical, and biological phenomena—collectively termed THMCB—in the context of microbial induced carbonate precipitation (MICP). This interdisciplinary analysis advances our understanding of how multifaceted environmental conditions drive MICP, a bio-mediated process with profound implications for soil stabilization, carbon sequestration, and infrastructure durability.
Microbial induced carbonate precipitation has rapidly emerged as a promising bio-geotechnical technique, leveraging the ability of certain bacteria to precipitate carbonate minerals. This process naturally reinforces soil matrices and mitigates permeability, making it a sustainable alternative to traditional engineering methods that often rely on toxic chemicals or intensive energy inputs. The reviewed article emphasizes the necessity to view MICP through the lens of THMCB coupling—a complex integration of thermal gradients, fluid flow, mechanical stress, chemical reactions, and microbial activity that collectively governs the efficiency and stability of carbonate precipitation in subsurface environments.
At the heart of this review lies a detailed exploration of how each component within THMCB influences MICP. Thermal effects, for instance, are scrutinized for their role in modulating microbial metabolism rates and enzymatic activities essential for carbonate formation. The authors note that temperature fluctuations can either accelerate or inhibit urease activity—a key enzyme facilitating carbonate precipitation—thus impacting nucleation rates and mineral growth. Understanding such thermal dependencies is crucial in designing MICP applications across diverse climatic conditions, from cold permafrost regions to heated industrial waste sites.
Hydraulic dynamics are another pivotal factor addressed through rigorous analysis. The transport and distribution of nutrients, microbes, and reactants within porous media are framed as functions of hydraulic conductivity and pressure gradients. The coupling here refers to how fluid flow modifies pore-scale environments, potentially creating zones of enhanced or diminished microbial activity. Variability in flow velocities also influences the spatial uniformity of precipitation, a considerable challenge when implementing MICP at field scale. The review suggests that controlling hydraulic parameters could optimize the homogenization of carbonate deposits and thus improve the mechanical reinforcement of treated soils.
Mechanical stresses, both natural and anthropogenic, interact intricately with the chemical and biological aspects of MICP. The paper delves into how soil deformation and strain fields impact microbial habitats and the distribution of precipitated carbonate crystals. Compression and shear stress are shown to affect pore connectivity and biofilm integrity, which in turn modulate the accessibility of ions required for mineralization. One particularly insightful discussion revolves around the feedback loop generated by mechanical consolidation—which tends to densify soil—and microbial activity, which may alter the mechanical properties of the medium over time.
Chemical reactions within the MICP process are highly complex, comprising urea hydrolysis, carbonate ion formation, and subsequent precipitation reactions dependent on pH, ion concentrations, and redox conditions. The comprehensive review highlights the sensitive balance of these parameters and how they shift with variations in ionic strength and contaminant presence. Furthermore, the interaction between injected chemical solutions and native geochemical conditions often induces secondary reactions that can either promote or hinder MICP effectiveness. This chemical coupling underscores the importance of precise geochemical characterization prior to field deployment.
Biological factors are extensively analyzed with a focus on microbial species selection, population dynamics, and metabolic pathways. The article stresses that not all ureolytic bacteria perform equally under differing THMC conditions, emphasizing the role of microbial adaptability and resilience. Biofilm formation is investigated as a double-edged sword; it facilitates stable microenvironments for precipitation but may also occlude pore spaces if unchecked. The coexistence of microbial communities introduces further complexity—interactions such as competition, symbiosis, and quorum sensing can considerably alter collective bioactivity and mineralization patterns.
A key contribution of this review is its emphasis on the feedback mechanisms linking these five domains of THMCB coupling. It argues that the isolated study of single parameters fails to capture emergent behavior critical for realistic modeling and prediction of MICP outcomes. The authors advocate for integrative approaches, combining advanced numerical simulations with empirical observations to decode the non-linear interactions and time-dependent evolution of the system. Through this, the research community can develop more accurate predictive tools tailored for specific site conditions and technological aims.
The review also addresses the scalability challenges faced when translating laboratory-scale MICP findings to field applications. Intrinsic heterogeneities in natural soils—ranging from mineralogy to moisture content—interact with THMCB factors to generate erratic results in carbonate precipitation. The synthesis provides practical recommendations for monitoring and controlling thermal and hydraulic conditions, as well as adaptive microbial management to overcome these site-specific challenges effectively. It stresses the role of multidisciplinary collaboration to navigate these complexities and achieve robust, sustainable implementations.
Environmental implications form a critical strand of discussion. Given the urgent global concerns surrounding carbon dioxide emissions and climate change, MICP’s potential as a carbon sequestration method garners significant attention. The review elucidates how coupling processes control carbonate mineral stability and long-term carbon storage capacity. It also highlights possible unintended consequences such as changes in local groundwater chemistry or microbial community shifts that could arise from large-scale MICP interventions, suggesting pathways for future risk assessment and mitigation strategies.
Technological innovation is equally prominent in the article’s narrative. By integrating THMCB coupling principles, engineers can design smart biogeotechnical materials and structures that adapt dynamically to environmental stimuli. For example, the article explores emerging self-healing concretes incorporating ureolytic bacteria, where thermal and mechanical stresses trigger targeted mineralization to repair cracks. Such bioinspired solutions herald a new era of green infrastructure, reducing lifecycle costs and environmental footprints.
Importantly, this review underscores the role of cutting-edge analytical techniques utilized to probe THMCB phenomena. From microfluidics to in situ spectroscopy and reactive transport modeling, these methodologies enable unprecedented resolution in tracking microbial behavior, ion fluxes, and mechanical changes during MICP. The article marvels at how these advances open avenues for discovering novel microbial strains and optimizing bioprocess parameters—a future poised at the intersection of microbiology, geochemistry, and environmental engineering.
The authors close their comprehensive inquiry by identifying knowledge gaps and charting a research roadmap prioritizing interdisciplinary integration. They call for the development of standardized experimental protocols and scaled pilot projects incorporating real-world heterogeneities. Additionally, the need for long-term monitoring frameworks is emphasized to assess durability and ecological compatibility. This strategic vision envisions THMCB-informed MICP as a cornerstone for next-generation approaches to environmental remediation, resource recovery, and climate change mitigation.
In summary, this authoritative review on thermal–hydraulic–mechanical–chemical–biological coupling in microbial induced carbonate precipitation represents a monumental step in decoding one of the most complex bio-mediated geochemical processes. Its insights pave the way for revolutionary applications in earth sciences and engineering, where the synergistic influence of physical, chemical, and biological forces can be harnessed to build resilient, sustainable systems. As this field continues to surge forward, the integration of THMCB concepts promises to unlock transformative solutions to some of the pressing environmental challenges of our age.
Subject of Research: Thermal–hydraulic–mechanical–chemical–biological (THMCB) interactions in microbial induced carbonate precipitation (MICP).
Article Title: Thermal–hydraulic-mechanical-chemical-biological (THMCB) coupling in microbial induced carbonate precipitation (MICP): A comprehensive review.
Article References:
Wang, J., Alidekyi, S.N., Nong, X. et al. Thermal–hydraulic-mechanical-chemical-biological (THMCB) coupling in microbial induced carbonate precipitation (MICP): A comprehensive review. Environ Earth Sci 84, 339 (2025). https://doi.org/10.1007/s12665-025-12327-9
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