Abstract:

Groundwater organic pollution poses a long-term threat to global sustainable development and water security. Fractured bedrock aquifers (including fractured porous sedimentary rocks, igneous rocks, and karstic carbonate rocks) are widely distributed and represent a major category of contaminated media by volatile organic compounds (VOCs). Quantifying the transport and diffusion processes of VOCs within fractured media is critical for environmental system protection and water resource security. However, at larger spatial scales, such modeling becomes highly complex, and achieving fast, convenient, and precise predictions of contaminant transport and diffusion fluxes remains a major challenge. Given this context, this paper analyzes the complexity of modeling VOCs transport and diffusion fluxes in fractured media and the challenges in achieving efficient and precise prediction. Furthermore, it proposes and elaborates on a comprehensive modeling framework for the efficient prediction of VOCs transport and diffusion fluxes in fractured media. It also explores corresponding methodologies for developing efficient statistical surrogate models and intelligent predictive models through illustrative case studies. Finally, the paper identifies key challenges warranting further research and proposes potential pathways to overcome these bottlenecks for the efficient and accurate modeling of VOCs transport and diffusion fluxes in fractured media. These include: a dimension-reduction equivalent modeling approach for efficient prediction; an integrated modeling framework leveraging knowledge graphs for deep, multi-dimensional fusion; artificial intelligence modeling driven by simulation data and enhanced by constitutive/statistical relationships; and the development of an intelligent software system, tailored to specific application scenarios and built upon the proposed integrated modeling framework, to deliver efficient and precise VOCs flux predictions in practice. The comprehensive modeling framework, the specific effective modeling methodologies, and the proposed pathways for future in-depth study will help address the challenge of efficient and accurate prediction and quantification of key interfacial fluxes of multiphase VOCs contaminants in complex groundwater environmental systems. This work is expected to provide crucial support for efficient groundwater remediation and optimal risk management.

Key words: fractured media, groundwater environment, non-aqueous phase liquids (NAPLs), volatile organic compounds (VOCs), efficient and precise prediction, integrated modeling framework