Advancing permeable reactive bio-barriers: A multi-field coupling approach for groundwater remediation

Permeable reactive bio-barrier (PRBB) technology represents an innovative groundwater remediation approach that utilizes strategically positioned microorganisms within porous media through bioaugmentation or biostimulation processes to intercept and treat contaminated groundwater flows. This technology has garnered substantial attention over recent decades due to its exceptional capability to leverage indigenous microorganisms and achieve superior contaminant removal efficiencies. Recent technological innovations have considerably expanded PRBB applications, allowing for the treatment of diverse contaminant profiles, including inorganic and organic compounds, as well as emerging and specific organic contaminants. These advancements facilitate complex contamination management and have enabled successful integration with electrokinetic enhancements to overcome conventional limitations. Despite these advancements, comprehensive understanding of PRBB performance under multi-field conditions remains inadequate, impeding further technological development. This review systematically analyzes the current state of knowledge regarding contaminant removal mechanisms, examines critical system components, and evaluates various configurations and installation methodologies of PRBBs. Furthermore, it thoroughly investigates the intricate interactions among biological, chemical and hydraulic fields, encompassing crucial factors such as geochemical parameters, microbial metabolic byproducts, hydraulically-induced biological availability, chemical reaction kinetics, and the combined effects of chemical and biological clogging phenomena. Although significant progress has been achieved, PRBBs face persistent challenges, involving enhancing microbial resilience, reducing clogging, and understanding system behavior under multi-field coupled conditions. This review concludes by presenting future research prospects from a multi-field perspective, providing strategic directions for advancing PRBB technology development and optimization. • Multi-field interactions in PRBBs are analyzed. • Geochemical conditions, microbial activity, and flow dynamics are linked to PRBB longevity & functional stability. • A framework is proposed for enhancing PRBB efficiency, resilience, and lifecycle management. • Strategic insights are provided to advance the adaptability, and scalability of PRBB technologies in complex field conditions.