Dahmke, Influence of mineral precipitation on the performance and long-term stability of Fe 0 -permeable reactive barriers: A review on the basis of 19 Fe 0 -reactive barrier sites Einfluss der Mineralpräzipitation auf die Funktionalität und Langzeiteffektivität von Fe 0 -Reaktionswänden — Ein Review anhand von 19 Fe 0 -Reaktionswandstandorten , Grundwasser , 10. Lo, Di He and Haoran Dong, The limitations of applying zero-valent iron technology in contaminants sequestration and the corresponding countermeasures: The development in zero-valent iron technology in the last two decades 1994—2014 , Water Research , 75 , 224 , 2015. Selection of material suitable for permeable reactive barriers in the vicinity of landfills This paper focuses on the criteria proposed for the selection of reactive materials suitable for permeable reactive barriers surrounding waste disposal sites. Woods, Fifteen-year assessment of a permeable reactive barrier for treatment of chromate and trichloroethylene in groundwater , Science of The Total Environment , 10. If the plume being treated has metals as well as organics the presence of sulfides may aid in precipitating them as metal sulfides. Kjellerup, Presence of organohalide-respiring bacteria in and around a permeable reactive barrier at a trichloroethylene-contaminated Superfund site , Environmental Pollution , 10. Elevated concentrations of sulfide may inhibit dechlorinating microorganisms and may pose taste and odor problems.
Protection and Remediation ed I. Trace metals and other contaminants in the environment, Nriagu J Series Ed. Thomas, Robert Kalin and Jonathan R. The impact of microbiological and geochemical processes has been a major concern for the long-term performance of permeable reactive barriers containing zero-valent iron Fe 0. Niño de Guzmán, Cathleen J.
This study demonstrates that biogeochemical influences on the performance and reaction of Fe 0 may be minimal in the short term e. Parameters and Rationale for Groundwater Performance Monitoring Parameter Rationale Primary contaminants Reductions in contaminant concentrations are the primary measure of performance. Although pore space has been lost due the accumulation of authigenic components, neither site shows evidence of pervasive pore clogging after four years of operation. 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. Sulfide By-product of sulfate reduction. Trace Metals and Other Contaminants in the Environment, Vol 7.
Blowes, Christopher Kalinowski, Jennifer M. Useful for identifying minerals such as carbonates, magnetite, and goethite. A number of case studies, experiences with large-scale modelling and test site experiments provide insight into the practical application of the results. Boreholes are backfilled with fresh reactive material. Numerous case studies are provided. Groundwater chemistry was found to significantly affect corrosion rates of Fe 0 filings and resulted in the formation of a suite of mineral precipitates. The technology can be applied in source areas or use groundwater recirculation to capture deeper plumes in an in situ bioreactor configuration.
Benson Evaluation of Two Strategies to Enhance the Long-Term Hydraulic Performance of Permeable Reactive Barriers , 2008. Useful for identifying morphology and composition of precipitates and corrosion materials. The third criterion — mechanical — that is related to the deformation and strength properties of the reactive material should be considered in designing the technology and evaluation of safety conditions. Useful for determining fraction of carbonates in core profile. The results of the six years experiment are discussed bellow.
The barrier must be long enough to treat the entire width of the plume dimension perpendicular to groundwater flow and should extend to and be keyed into an impermeable layer. Indraratna, Selection of potential reactive materials for a permeable reactive barrier for remediating acidic groundwater in acid sulphate soil terrains , Quarterly Journal of Engineering Geology and Hydrogeology , 10. Maximum net reductions in porosity due to the accumulation of sulfur and inorganic carbon precipitates range from 0. Amendments can be added to stimulate both biotic and abiotic degradation processes, based on the type of contaminant s present and the desired degradation pathway s to be stimulated. The rates of both biological and chemical reactions e.
When approaching the wall, an increasing gradient can indicate reduced permeability in the barrier. Many compounds have regulated intermediate products that also are analyzed for. The report also contains recommendations for the groundwater monitoring networks based the results of these qualitative and quantitative evaluations. Note that both are readily degraded by bacteria and their low concentrations or absence does not necessarily mean incomplete dechlorination Scott et al. As a result uranium can migrate from the uranium containing waste deposits waste rock pile, tailings ponds, etc. Laboratory Testing Using Site Groundwater. The document points out the important considerations and various available options applicable to permeable barriers that should be taken into account during design, implementation, and monitoring.
Phospholipid fatty acids Indicator of bioactivity, measure of biomass, and characterization of the microbial community. Benson Evaluation of Two Strategies to Enhance the Long-Term Hydraulic Performance of Permeable Reactive Barriers , 2008. Biological and chemical oxygen demand Secondary water-quality parameters that may also be used as an indication of substrate demand. Millner, Alba Torrents, Dana Jackson and Birthe V. . Therefore uranium sorption on soil particles anion exchange capacity of which is low is weak.
The principal conclusion of this review is that the most significant problems have been the result of insufficient characterization, which resulted in poor engineering implementation. Long-Term Performance of Permeable Reactive Barriers Roehl; K. Carbon dioxide By-product of both aerobic and anaerobic biodegradation processes. Recommended Characterization Techniques for Coring Samples Analysis Method Description Total Carbon Analysis Combustion furnace used to quantify total organic and inorganic carbonate carbon Quantitative determination of total carbon. Considering the lowest cost of the reactive materials, the required thicknesses of activated carbon, zeolite and zero valent iron were calculated using two different algorithms. Recommended analyses and data use are found in Table 2. 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.