Multi-scale investigation of long-term performance of permeable reactive barrier systems subjected to (bio)passivation.

Graphene-supported micron zero-valent iron cooperates with immobilized microorganisms for long-term efficient chlorinated organics remediation.

Electrokinetic dual-cathode permeable reactive barrier system: Efficient Cr(VI) removal and Cr(III)/Fe(III) resource recovery from contaminated soil

Pharmaceuticals such as paracetamol and diclofenac (DCF) are among the most extensively consumed drugs worldwide and are continuously released into municipal and hospital wastewater due to incomplete human metabolism. Their persistent presence in aquatic environments, typically ranging from ng/L to µg/L, raises concerns due to endocrine disruption, chronic toxicity, and the promotion of antimicrobial resistance. Conventional wastewater treatment plants (WWTPs) remove 70–90% of ACT but less than 30% of DCF, primarily because these systems were not designed to target low-concentration, recalcitrant micropollutants. As a result, pharmaceuticals frequently pass into treated effluents, highlighting the need for advanced, sustainable, and passive treatment solutions. Permeable reactive barriers (PRBs) have emerged as a promising technology for the interception and removal of pharmaceuticals from both wastewater treatment plant effluents and groundwater. This review provides a comprehensive assessment of ACT and DCF occurrence, environmental behavior, and ecotoxicological risks, followed by a detailed evaluation of PRB performance using advanced reactive media such as geopolymers, activated carbon, carbon nanotubes, and hybrid composites. Reported removal efficiencies exceed 90% for ACT and 70–95% for DCF, depending on media composition and operating conditions. The primary removal mechanisms include adsorption, ion exchange, π–π interactions, hydrogen bonding, and redox transformation. The novelty of this review lies in systematically synthesizing recent laboratory- and pilot-scale findings on PRBs for pharmaceutical removal, identifying critical knowledge gaps—including long-term field validation, media regeneration, and performance under realistic wastewater matrices—and outlining future research directions for scaling PRBs toward full-scale implementation. The study demonstrates that PRBs represent a viable and sustainable tertiary treatment option for reducing pharmaceutical loads in aquatic environments.

Core-shell nZVI@NC as a scalable PRB filler for remediating PFOA-contaminated groundwater via synergistic adsorption.

Combined phytoremediation and permeable reactive barriers for integrated cadmium control in soil-groundwater systems: Mechanisms, efficiency, and microbial synergy

Study on the adsorption mechanism and durability of non-sintered composite ceramsite as permeable reactive barrier filler for Pb2+

Acid mine drainage (AMD), containing excessive sulfates and heavy metals, poses a severe threat to the environment and human health. In this study, a laboratory-scale column device using varying ratios of coarse sand to carbon steel slag (CS/CSS) as the filled material was designed to efficiently remove typical pollutants in AMD. Results revealed that the removal rates of SO42−, Fe, Mn, and Zn, as well as the pH value of the solution were influenced by the ratio of CS/CSS. The highest removal rates of SO42−, Fe, Mn, and Zn were 92%, 99.99%, 99.98%, and 99.99%, respectively, for CS/20%CSS. Additionally, XPS and SEM results indicated that sulfate (SO42−) existed in that groups associated with CaSO4 and Fe-sulfate complexes, while Fe, Mn, and Zn were simultaneously attached to the surface of the materials in the form of ion exchange, hydroxides, and co-precipitates. A modified sequential extraction method (BCR) results indicated that the distribution patterns of Fe, Mn, and Zn varied with increasing CSS content. Notably, when the CSS content in the column reached 20%, the metal ions were predominantly adsorbed in the top layer. The Risk Assessment Code values for Fe exhibited a low risk to the environment. These results highlight the importance of optimizing the CSS content in the permeable reactive barrier (PRB) to balance removal efficiency and permeability. Consequently, it is recommended that the content of CSS in the PRB should be maintained below 10% to ensure optimal performance and permeability. This study provides a foundation for optimizing PRB filled material design to enhance its efficiency and environmental sustainability in AMD treatment.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-26562-4.

Groundwater quality is essential for water supply, and the threat of groundwater pollution poses significant risks to society and the economy. This study investigates the removal of two common pollutants, nitrate and MTBE, using chemical reduction with zero-valent iron (ZVI) and adsorption with ZSM-5, respectively, within a permeable reactive barrier (PRB). Specifically, the research evaluates the performance of two structures: a material composition system that integrates reactive materials into a single barrier and a sequential barrier system with separate layers of ZVI and ZSM-5 for the simultaneous removal of these pollutants. The study investigates the effects of four variables: initial concentrations of nitrate and MTBE and dosages of ZVI and ZSM-5, each analyzed at five levels. The results demonstrate that the material composition system was more effective at nitrate removal, with an efficiency increase from 88% (using ZVI alone) to approximately 97%. However, this system exhibited a reduced MTBE removal efficiency, decreasing from over 99% (achieved with ZSM-5 alone) to around 86%, likely due to nitrate interference. Conversely, the sequential barrier structure outperformed the material composition system in MTBE removal, achieving a maximum efficiency of 95%. However, its nitrate removal efficiency was lower, at around 92%, which, while still acceptable, was less effective than that of the material composition system. In summary, the material composition system is more suitable for nitrate removal, whereas the sequential barrier system is better suited for MTBE removal. This study provides valuable insights into optimizing PRB designs for the simultaneous remediation of groundwater contaminants.

Hydrogeochemical and machine learning evidences for release and attenuation mechanisms of chromium contamination in a partially PRB remediation of shallow groundwater.

Periodic Na2S addition enables in-situ FeS loading on permeable reactive barrier for sustainable removal of Cd2+/Cu2+ from acid mine drainage

ABSTRACT An investigation was conducted to evaluate hydraulic performance and chemical clogging of the concrete permeable reactive barrier (PRB) used to treat acid mine drainage (AMD). The pervious concrete PRB system is an emerging technology for AMD treatment. In the present study, pervious concrete mixtures were prepared at a 0.27 water/cementitious ratio using CEM I 52.5R cement with or without 30% fly ash and 9.5 mm granite aggregate. The AMD types used were obtained from a gold mine and from a coal mine. Porosity and permeability properties of the pervious concretes were measured before and after use to treat AMD. Subsequently, 2D slice image analyses were done using X-ray microcomputed tomography (microCT). It was found that the heavy metals comprising Al, Zn, Fe, Mn, Mg, Ni and Co, were removed at the high removal efficiency (RE) levels of 70–100%. Interestingly, critical reductions in porosity (P-crit) and permeability (K-crit) values were utmost at a short distance of 75 mm from the entrance, forming bottleneck clogging. Results showed that chemical clogging that ensued progressively during the experiment, adversely gave values of up to 30–40% reduction in RE values, up to 30–40% reduction in P-crit and 80–90% reduction in K-crit. MicroCT analysis of pore connectivity confirmed the occurrence of bottleneck clogging in the column reactors. Further studies are needed to investigate the long-term adverse impacts of chemical clogging that could potentially be employed to determine the PRB’s longevity.

Long-term field study of a permeable reactive barrier for groundwater clean-up at an acid battery recycling site.

Reactive and hydraulic behavior of pilot scale H2O2-assisted PRB in remediating landfill contaminated groundwater.

Zoned bioremediation of trichloroethene and toluene co-contaminants using immobilized anaerobic consortia in saturated porous media.

Incorporating lateral bypass in the design of horizontal permeable reactive barriers (HPRBs) for chlorinated vapor intrusion mitigation

The escalating contamination of water resources by heavy metals and organic pollutants poses a significant environmental challenge, particularly in regions like Zhambyl (Kazakhstan), where water quality varies from moderately to extremely polluted. This study focuses on optimizing biochar production from agro-industrial waste, specifically rice husk, from the Zhambyl region, employing Response Surface Methodology (RSM) toenhance its applicability in Permeable Reactive Barriers (PRBs) for groundwater remediation. Through the Box-Behnken design, key pyrolysis parameters–temperature, activation time, and the ratio of rice husk to phosphoric acid (H₃PO₄)–were systematically varied to maximize biochar yield and adsorption capacity. Statistical analysis using ANOVA validated the quadratic model’s significance (p < 0.05, R² = 0.9662), identifying optimal conditions at approximately 2.2 g H₃PO₄ and 540°C, yielding up to 84% biochar. These findings underscore the potential of optimized biochar as a sustainable, cost-effective material for environmental remediation, particularly in PRB systems.

Multi-contaminant removal from synthetic mine-impacted water by permeable reactive barriers under cold conditions.

Application of spectral induced polarization technique in monitoring zinc removal by activated carbon as a permeable reactive barrier material.

Bio-augmented permeable reactive barriers for groundwater remediation: A comprehensive review.