This is the web site of RUBIN in English, the novel large-scale German Permeable Reactive Barrier (PRB) R&D network, covering more than 10 innovative PRB projects in Germany. The program is entirely funded by the German Federal Ministry for Education and Research (BMBF). Various, up-to-date information on RUBIN is available, but in addition valuable data of ALL German PRBs can be retrieved.

  1. Introduction
  2. Current status of PRB technologies worldwide
  3. Current issues regarding PRB technologies
  4. Development in Germany
  5. Missions, goals and structure of the German PRB network RUBIN

More than 10 permeable reactive barrier (PRB) projects, among them participants from different universities, companies, consultants and problem owners, join and co-operate intimately in the interdisciplinary German PRB network/concerted action "RUBIN" for the "Use of Treatment Walls for Site Remediation" that was initiated and set up by the German Federal Ministry for Education and Research (BMBF) in 2000. RUBIN stands for (in German) "Reaktionswände und -barrieren im Netzwerkverbund" meaning in English "reactive wall and barrier projects cooperating in a network/concerted action".

The focus of RUBIN´s missions and goals is to meet current R&D needs pertaining to the practical set up and longterm operation of PRBs as a prospective remediation technology in a large-scale, coordinated initiative. Especially a bundle of technical, operational, economic, ecological, toxicological, administrative and legislative issues as well as issues comprising longterm performance and stability are addressed and investigated. Therefore, RUBIN is scheduled to plan, design, implement, monitor and evaluate pilot and full-scale PRB projects in Germany in order to check and assess as thoroughly and precisely as possible applicability, performance and limits of PRBs in a broad technical scope combined with an intensive, simultaneous scientific backup. The network also covers novel innovative approaches to be utilized for eliminating recalcitrant compounds from contaminated groundwater by means of innovative reactive materials and novel barrier design and construction methods.

Although a growing number of demonstration sites for PRBs, predominantly involving treatment of chlorinated ethenes by granular iron metal, have proven successful in principle in North America, so far, PRBs have not been fully accepted and therefore established as new general remediation technologies in Europe. The lack of general acceptance and missing incentives to implement PRBs in full scale and in a wide scope are due to, among other things, still insufficient or missing comprehensive reliable information on long-term aspects, e.g. longevity, long-term effect and performance, and, associated with these items, the overall rentability. In Germany, 9 pioneering PRB projects (full and pilot scale) have been implemented over the last 3-4 years revealing promising preliminary results, e.g., in Bernau (built 2001), Bitterfeld (1999), Denkendorf (2000), Edenkoben (1998, 2001), Karlsruhe (2000), Oberursel (2002), Reichenbach (2000), Rheine (1998) and Tübingen (1998), all revealing interesting design and engineering features. Therefore, the German BMBF decided to evaluate and assess the performance of PRBs as well as other material issues to a greater extent and in a broader scope by means of RUBIN.


As representing passive in situ groundwater remediation techniques and therefore avoiding several immanent technical drawbacks of active systems a priori, PRBs are currently regarded as promising upcoming alternatives to common active groundwater remediation technologies like pump-and-treat (Gavaskar et al., 2000, Rochmes, 2000, United States Environmental Protection Agency (U.S. EPA), 1998, 1999 and 2002, Vidic, 2001). Although installation costs are generally higher than those of other groundwater remediation technologies, O&M costs are significantly lower, provided that the PRB will not have shown an unexpected malfunction before the year in which costs are recovered. O&M costs of PRBs are mostly due to monitoring measures, which are required for all remediation approaches as well. There is no permanent and massive intervenience into the aquifer, and the remediation takes place in the subsurface directly inside the contaminated aquifer, i.e., no costly installations or a specific plant have to be set up, which had to be operated and maintained during a long-term run in the range of several years or even decades. In addition, the land use can resume after the installation of a PRB system, since there are few visible signs of installation above ground except for the monitoring wells.

The first PRB was set up at Borden, Ontario (Canada), in June 1991 as a pilot-scale, continuous reactive barrier (CRB) using zero-valent iron (ZVI = elemental iron metal) for treatment of perchloroethene (PCE) and trichloroethene (TCE). The project could be implemented after pioneering preparatory basic work of different researchers, especially of Prof. ROBERT GILLHAM and his staff (e.g., Stephanie O´Hannesin and other co-workers) of the University of Waterloo, Ontario: iron filings collected from a local machine shop mixed with sand were deployed. The first full-scale system was installed in 1995 in Sunnyvale, California (U.S.A.) as a funnel-and-gate (F&G) PRB. This systems utilizes 100 % ZVI to treat TCE, dichloroethene (DCE), vinylchloride (VC) and chlorinated fluorocarbons (CFC). Since 1995, the number of U.S. pilot and full-scale PRBs has steadily increased (U.S. EPA, 2002), particularly between 1998 and 1999 (in 2002, there are about 40 PRBs in total). Predominantly, chlorinated volatile organic carbons (cVOCs) like chlorinated ethenes (PCE, TCE) are dehalogenated via intermediates to chlorine-free degradation products (in case of PCE or TCE, e.g., via DCE and VC to halogen-free ethene as one major degradation product) using technical ZVI that serves as the dehalogenation reagent (mainly in the form of small filings or granules). CRBs meanwhile prove to be in favor of F&G due to economic and operational reasons. Some PRBs have been already run for more than 7 years (2002) revealing constantly high degradation rates of the pollutants, e.g., the pilot-scale F&G systems at the Moffett Federal Airfield, Mountain View, California, built during April 1996 (cVOCs are dehalogenated with ZVI), and at Dover Air Force Base, Delaware, set up in December 1997 (cVOCs are dehalogenated with ZVI as well). Recently published, comprehensive reports present and discuss extensive results from investigating several installations regarding key issues like long-term performance (Gavaskar et al., 2000 and 2002).

Besides chlorinated hydrocarbons (CHC) and certain radioactive elements, PRBs have been relatively rarely applied to other groundwater contaminants so far, like "common" heavy metals (e.g., lead, zinc, cadmium, copper), PAHs or other aromatics like benzene, toluene, ethylbenzene or xylenes (BTEX), because suitable and affordable reactive materials are still lacking or are currently under development only (Scherer et al., 2000). Activated carbon seems to be a promising reagent for the adsorptive removal of PAHs and other contaminants like highly persistent CHC, because PAHs can not be degraded on ZVI, namely as well chlorinated aromatics (Gavaskar et al., 2000, Scherer et al., 2000), due to the relatively low reduction potential of ZVI. One solution for getting rid of these components as well have been demonstrated by using in situ hydrogenation catalysts like palladium, which enables to dehalogenate nearly every recalcitrant polyhalogenated pollutant completly within minutes. Nevertheless, pure palladium is usually very expensive, toxic and may be quickly deactivated by other groundwater ingredients or their reaction products like sulfide. Fortunately, it could be demonstrated recently that all of these problems can be effectively overcome by using special solid supports like zeolites (Dr. Christoph Schüth, University of Tübingen) or encapsulating the palladium in silicon tubes (Prof. Frank-Dieter Kopinke, Dr. Karin Mackenzie, UFZ Leipzig). Both inventions are intensively tested at the SAFIRA test site at Bitterfeld, at the drain-and-gate PRB in Denkendorf and at the f&g PRB at Bernau in field scale. Furthermore, a novel, emerging trend regarding reactive materials seems to be combining different reactive and/or sorptive materials like iron and activated carbon that perform already well and economic in PRBs where each of them is applied exclusively (Weiß et al., 1999, SAFIRA, 2002).


PRBs are not appropriate for all applications (Vidic, 2001). Moreover, PRB technologies have not already gained general acceptance as established remediation technologies so far, especially across Europe, due to several reasons:

  1. There is a certain lack of reliable information on long-term performance, longevity and long-term effect, because of still missing long-lasting projects in the range of decades (Puls et al., 2000, Yoon et al., 2000, Rochmes, 2000, Sarr, 2001, Simon et al., 2001, Vidic, 2001).
  2. There is a demand for identifying all degradation pathways as well as determining precise mass balances. The considerable toxicity of intermediary or final dehalogenation products like cis-DCE, VC or ethene is also critically discussed (Wienberg, 1997).
  3. Only insufficient information is currently available on the rentability of PRBs, especially, if the performance decreases over time.
  4. The knowledge about the applicability and longevity regarding combined contamination scenarios, especially when being very heterogeneous and complex, is in a very early stage at the moment (Rochmes, 2000, Scherer et al., 2000).


Addressing the issues mentioned above, the German EPA (Umweltbundesamt, UBA) already stated in late 1997 that R&D as well as technical implementations of PRB projects had to be boosted in order to investigate their potentials and limits (Burmeier, 1997). "SAFIRA" (i.e., "Sanierungsforschung in regional kontaminierten Aquiferen", meaning in English "remedial research applied to regionally contaminated aquifers"), a R&D network using specifically designed in situ reactors in a semi-technical scale for testing different reactive materials, was the first initiative to study the potentials of PRBs in a broader scope (Weiß et al., 1999). The pilot plant treats groundwater contaminated by a complex mixture of CHCs, i.e., mainly chlorobenzenes, and other pollutants at Bitterfeld, Federal State of Saxony-Anhalt. In order to promote the technical development of full-scale PRBs, the German Federal Ministry of Education and Research (BMBF) set up another PRB concerted action "RUBIN" (i.e., "Reinigungswände und -barrieren im Netzwerkverbund", meaning in English "PRB projects co-operating in a network/concerted action"), consisting of several PRB projects (Birke et al., 2001).

In Germany, 9 PRB pilot projects, all showing some good first tendencies regarding efficiency of degradation or removal of contaminants and rentability, have been implemented over the last 3-4 years, namely in Rheine (cVOCs, iron filings and iron sponge, pilot scale, continuous wall), Tübingen (cVOCs, granular iron, full scale, funnel and gate), Karlsruhe (PAH, activated carbon, full scale, funnel and gate), Edenkoben (cVOCs, iron filings, pilot scale, expanded to full scale (since 2001), funnel and gate), Denkendorf (cVOCs, activated carbon, full scale, drain and gate), Bitterfeld (CHC like chlorinated benzenes, PAH, microbiological degradation and palladium and iron plus activated carbon in different reactors, pilot scale with focus on R&D, specific reactor systems), Reichenbach (cVOCs, activated carbon, full scale, specific design), Bernau (cVOCs, iron filings, pilot scale) and Oberursel (cVOCs, iron granules, full scale, funnel and gate).

Important ongoing R&D work has been performed at the University of Tübingen and the University of Kiel and at the Umweltforschungszentrum Leipzig over the last years.

Owing to these projects, initiatives and other activities in Germany, the importance of PRBs for groundwater remediation became aware to the German public, and its potentials have been recognized to a greater extent. Significant progress has been made over the last years to better understand and predict long-term stability. Thus, there is a strong support for testing and evaluating this technique, furthermore, for developing new concepts and solutions.


In order to support and promote the technical development of PRBs, the BMBF set up RUBIN in 2000. RUBIN´s time schedule is about 4 years. At least about 4 Mio EUR will be provided and spent for that term.

Detailed missions and goals of RUBIN are given below:

  1. RUBIN´s projects are expected to deliver comprehensive data, informations, knowledge and problem solutions for different areas like planning and design, construction and operation, monitoring, economics, ecological effects, regulatory issues and enhancing acceptance of administrations and problem owners.
  2. The projects of RUBIN are therefore focussed on the set up and operation of pilot and full scale PRB installations. Experts and highly skilled personal from research institutions (universities), developers (universities and companies), planners (consultants, environmental technology and engineering companies), executives (builders and contractors, highly specialized civil engineering companies) and administrations co-operate interdisciplinarily. Data have to be collected from as much as possibly different sites and installations.
  3. RUBIN is expected to deliver extensive information for a reliable assessment of benefits and drawbacks as well as a precise prediction of the applicability and rentability of a PRB regarding a concrete, single remediation scenario.
  4. Since RUBIN includes the already built PRB in Rheine, first investigations of long-term aspects can be implemented. Therefore, with the help of RUBIN, experts are getting opportunity of testing already running German PRB installations (the Tübingen PRB will be included by the work of the University of Kiel to some extent, too).
  5. RUBIN shall provide quality standards and a generally applicable quality management scheme for the construction, operation and monitoring. Approaches for an improved monitoring and more reliable preliminary examinations are developed.
  6. Both investment and overhead costs of all RUBIN projects will be scrutinized and will deliver a data set for more precise approaches for calculations of rentability, especially compared to a common pump and treat measure in every case.

The RUBIN member projects can be classified into two groups: six site-specific projects, which are partly associated with several further sub-contractors/projects, deal with planning and/or setting up and/or operating as well as monitoring an actual PRB construction. Three further projects attend to general issues (spanning projects, non-site-specific). An overview is given under rubin->projects->overview. The gathered findings will be covered by a general manual mainly consisting of a state-of-the-art report and a main connecting thread for planning, design, construction and operation of PRBs in Germany.

On Sept. 6th 2001, the set up of the funnel and gate system at the Bernau site was successfully finished. Managed by the "Brandenburgische Boden Gesellschaft für Grundstücksverwaltung und -verwertung mbH (BBG)", this was the first RUBIN project to erect and operate a new PRB in Germany.

3 other RUBIN projects deal with important general issues and aspects:

At the University of Tübingen (G. Teutsch, M. Finkel), there is ongoing work comprising development of models for estimation and prediction of costs and rentability calculations; a comparative economical assessment is performed for the PRB technique versus innovative pump and treat systems.

At the University of Kiel, A. Dahmke and M. Ebert perform in co-operation with R. Wienberg, Hamburg, a comparative laboratory and site study for the evaluation and further development of preliminary investigation procedures, monitoring and quality management. One focus of this work is on scrutinizing degradation mechanisms and solving issues regarding side reactions as well as determining mass balances, especially for the dehalogenation of cVOCs like PCE and TCE by ZVI, using column and field data.

The University of Applied Sciences North-East Lower Saxony (H. Burmeier, V. Birke and D. Rosenau), Suderburg, co-ordinates the general work and results of the network and will be responsible for making up a general manual covering a state-of-the-art report and a guidance for implementation of PRBs in form of a main connecting thread, which has to be adapted to the already existing, general regulations and laws for remediation of contaminated sites in Germany. Therefore, the main connecting thread will cover descriptions, advices and instructions for cost calculations, planning, design, administrative regulations/approval, erection and operation as well as monitoring of PRBs.


Birke, V., Burmeier, H., and Rosenau, D. (2001). "New large scale PRB network RUBIN launched in Germany." 2001 International Containment & Remediation Technology Conference and Exhibition, Orlando, Florida, (May 1st, 2002)

Burmeier, H. (1997). "Die Bedeutung des Innovationspotentials von durchströmten Reinigungswänden für die Sanierung von Altlastenstandorten in Deutschland." Sanierung von Altlasten mittels durchströmter Reinigungswände, Vorträge und Diskussionsbeiträge des Fachgespäches am 27.10.1997 im Umweltbundesamt in Berlin, Umweltbundesamt, ed., Berlin, Germany, 6-21.

Gavaskar, A., Gupta, N., Sass, B., Janosy, R., and Hicks, J. (2000). "Final design guidance for application of permeable reactive barriers for groundwater remediation." Battelle Press, Columbus, Ohio.

Gavaskar, A., Sass, B., Gupta, N., Drescher, E., Yoon, W.-S., Sminchak, J., Hicks, J., and Condit, W. (2002). "Final report evaluating the longevity and hydraulic performance of permeable reactive barriers at Department of Defense sites." Battelle Press, Columbus, Ohio.

Puls, R.W., Korte, N., Gavaskar, A., and Reeter, Ch. (2000). "Long-term performance of permeable reactive barriers: an update on a U.S. multi-agency initiative." Contaminated Soil 2000 (Proceedings of the Seventh International FZK/TNO Conference on Contaminated Soil 18-22 September 2000), Leipzig, Germany, 591-594.

Rochmes, M. (2000). "Erste Erfahrungen mit Reaktiven Wänden und Adsorberwänden in Deutschland." Boden und Altlasten Symposium 2000, Franzius, V., Lühr, H.-P., and Bachmann, G., eds., Berlin, 225-245.

"SAFIRA." (Sept. 1st, 2002).

Sarr, D. (2001). "Zero-Valent-Iron Permeable Reactive Barriers - How Long will they Last?" Remediation, Spring 2001, John Wiley & Sons, Inc., 2001, 1-18.

Scherer, M. M. S., Richter, S., Valentine, R. L., and Alvarez, P. J. J. (2000). "Chemistry and microbiology of reactive barriers for in situ groundwater cleanup." Crit. Rev. Environ. Sci. Technol., 30(3), 363-411.

Simon, F.-G., Meggyes, T., Tünnermeier, T., Czurda, K., and Roehl, E. K. (2002). "Long-Term Behaviour of Permeable Reactive Barriers Used for the Remediation of Contaminated Groundwater." ICEM´01 Proceedings of the 8th International Conference on Radioactive Waste Management and Environmental Remediation, Bruges, Belgium, Sep. 30th-Oct. 4th, 2001 (Eds.: Taboas, A., VanBrabant, R., and Benda, G.). New York, The American Society of Mechanical Engineers, ISBN 0-7918-3590-1.

ited States Environmental Protection Agency (1998). "Permeable reactive barrier technologies for contaminant remediation." EPA/600/R-98/125, Washington DC.

United States Environmental Protection Agency (1999). "Field applications of in situ remediation technologies: permeable reactive barriers." EPA-542-R-99-002, Washington DC.

United States Environmental Protection Agency (2002). "Field applications of in situ remediation technologies: permeable reactive barriers." Washington, DC.

Vidic, R. D. (2001). "Permeable reactive barriers: case study review." GWRTAC E-Series Technology Evaluation Report TE-01-01, Ground-Water Remediation Technologies Analysis Center, Pittsburgh, PA.

Weiß, H., Daus, B., and Teutsch, G. (1999). "SAFIRA 2. Statusbericht; Modellstandort, Mobile Testeinheit, Pilotanlage." UFZ-Bericht Nr. 17 (UFZ report #17), ISSN 0948-9452, Leipzig, Germany.

Wienberg, R. (1997). "Vollständige, stoffspezifische Bilanzen des Schadstoffumsatzes beim Einsatz reaktiver Wände." Sanierung von Altlasten mittels durchströmter Reinigungswände, Vorträge und Diskussionsbeiträge des Fachgespäches am 27.10.1997 im Umweltbundesamt in Berlin, Umweltbundesamt, ed., Berlin, Germany, 112-119.

Yoon, S. W.-S., Gavaskar, A., Sass, B., Gupta, N., Janosy, R., Drescher. E., Cumming, L., and Hicks, J. (2000). "Innovative construction and performance monitoring of a permeable reactive barrier at Dover Air Force Base." Chemical Oxidation and Reactive Barriers: Remediation of Chlorinated and Recalcitrant Compounds. The Second International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, California, May 22-25, 2000, C2-6, Battelle Press, 409-416.