While extensive research has been performed on many technological aspects of permeable reactive barriers and a number of contaminants have so far been successfully treated by PRB systems, long-term performance has not been extensively considered and little is known about the processes influencing long-term behaviour. This gap in our knowledge is all the more disadvantageous as design life has a decisive influence on the economic viability of PRBs. The book describes methods for evaluation and enhancement of the long-term performance of PRB systems, especially of those targeting heavy metals, specifically uranium, and organic contaminants by sorption and/or precipitation mechanisms. Major topics in the book are: Selection and characterisation of suitable reactive materials Characterisation of the relevant contaminant attenuation processes Developing new contaminant-binding chemical compounds ("ligands") Accelerated testing methods to assess the long-term performance of the attenuation mechanisms in PRBs Evaluation of the influence of site characteristics on PRB performance Monitoring of existing and new field installations Coupling of electrokinetic techniques and PRB systems Large-scale laboratory and field tests and their results It addresses the long-term performance of PRBs, an important feature of this novel remediation technology, systematically. It deals extensively with heavy metal removal, with special emphasis on uranium. A number of case studies, experiences with large-scale modelling and test site experiments provide insight into the practical application of the results. This volume will contribute to the science underpinning groundwater remediation, and this will result in the improvement of quality of life and health and safety. * A systematic approach to investigating the long-term performance of permeable reactive barriers * Development of new contaminant-binding chemical compounds ("ligands"), accelerated testing methods to assess the long-term performance, and efficiency enhancing electrokinetic techniques * Extensive data and information on a Hungarian uranium mining facility; once a carefully kept secret of the Soviet Union

Remediation of groundwater is complex and often challenging. But the cost of pump and treat technology, coupled with the dismal results achieved, has paved the way for newer, better technologies to be developed. Among these techniques is permeable reactive barrier (PRB) technology, which allows groundwater to pass through a buried porous barrier that either captures the contaminants or breaks them down. And although this approach is gaining popularity, there are few references available on the subject. Until now. Permeable Reactive Barrier: Sustainable Groundwater Remediation brings together the information required to plan, design/model, and apply a successful, cost-effective, and sustainable PRB technology. With contributions from pioneers in this area, the book covers state-of-the-art information on PRB technology. It details design criteria, predictive modeling, and application to contaminants beyond petroleum hydrocarbons, including inorganics and radionuclides. The text also examines implementation stages such as the initial feasibility assessment, laboratory treatability studies (including column studies), estimation of PRB design parameters, and development of a long-term monitoring network for the performance evaluation of the barrier. It also outlines the predictive tools required for life cycle analysis and cost/performance assessment. A review of current PRB technology and its applications, this book includes case studies that exemplify the concepts discussed. It helps you determine when to recommend PRB, what information is needed from the site investigation to design it, and what regulatory validation is required.

Research described in this research brief explores the geochemical and microbiological processes occurring within zero-valent iron treatment zones in permeable reactive barriers that may contribute to decreases in iron reactivity and decreases in reaction zone permeability that, in turn, may eventually lead to system plugging and failure. Using advanced surface analytical techniques together with detailed coring and water sampling programs at two geographically, hydrogeologically, and geochemically distinct iron barrier installation sites, specific objectives of this research project were to: 1) Characterize the type and nature of surface precipitates forming over time at the upgradient aquifer/iron interface, within the iron zone, and at the downgradient/iron interface. 2) Develop conceptual models that predict the type and rate of precipitate formation based on iron characteristics and water chemistry. 3) Identify type and extent of microbiological activity upgradient, within and downgradient in at least one of the chosen sites to evaluate microbiological response or effects from emplaced iron into an aquifer system. 4) Develop practical and cost-effective protocols for long-term performance assessments at permeable reactive barrier installations.