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. It deals extensively with heavy metal removal, with special emphasis on uranium. Based on literature and laboratory test results residence time, density and hydraulic coefficient , a selection of layers of reactive materials was determined. Water levels Measure groundwater gradient for flow direction determination. To evaluate potential biogeochemical impacts, laboratory studies were performed over a 5-month period using columns containing a diverse microbial community. Suitable for identifying iron oxides and hydroxides, sulfides, and carbonates.
Useful for determining fraction of carbonates in core profile. 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. 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. Temperature and conductivity Primarily used as well-purging parameters. Phospholipid fatty acids Indicator of bioactivity, measure of biomass, and characterization of the microbial community.
Hydraulic and sorption criteria are equivalents and complementary to one another in the process of reactive material selection. Hudak, Evaluation of reactive well networks for remediating heterogeneous aquifers , Journal of Environmental Science and Health, Part A , 43 , 7 , 731 , 2008. 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. 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. The rates of both biological and chemical reactions e. Volatile fatty acids Biodegradation breakdown products and fermentation substrates.
Slater, Bernd Kulessa, Andrew S. Measurements of dissolved inorganic ions in one gate indicate that calcite and siderite precipitation in the gate could reduce gate porosity by about 0. When possible, these costs are compared with the cost of pump-and-treat technology for similar situations. A number of these parameters are specific to biotic or abiotic walls and their use is site specific. Hardness and total dissolved solids General water-quality parameter; used as an indication of secondary water quality. Nitrogen, phosphate, and potassium Nutrients needed for microbial growth.
Useful for identifying minerals such as carbonates, magnetite, and goethite. Biological and chemical oxygen demand Secondary water-quality parameters that may also be used as an indication of substrate demand. Only a material that fulfills both criteria should be used. Blowes, Christopher Kalinowski, Jennifer M. At both sites, consistent patterns of spatially variable mineral precipitation and microbial activity are observed.
Long-Term Performance of Permeable Reactive Barriers Roehl; K. May be used for geochemical modeling. Although major failures of in-ground treatment barriers have not been problematic to date, the accumulation of iron oxyhydroxides, carbonates, and sulfides from biogeochemical processes could reduce the reactivity and permeability of Fe 0 beds, thereby decreasing treatment efficiency. If the plume being treated has metals as well as organics the presence of sulfides may aid in precipitating them as metal sulfides. Protection and Remediation ed I. The substrates are mixed with common construction materials sand, gravel to prevent compaction and maintain permeability.
Costs were broken out into four general categories: site characterization, design, construction, and operation and maintenance. Therefore uranium sorption on soil particles anion exchange capacity of which is low is weak. This can also be done using flowmeters. Niño de Guzmán, Cathleen J. Benson Evaluation of Two Strategies to Enhance the Long-Term Hydraulic Performance of Permeable Reactive Barriers , 2008. Laboratory Testing Using Site Groundwater. Inyang, Competitive Effects on the Dechlorination of Chlorinated Aliphatic Hydrocarbons by Zero-valent Iron, Zero-Valent Iron Reactive Materials for Hazardous Waste and Inorganics Removal , 10.
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. Using multi-depth well clusters, measure vertical head differences along the upgradient and downgradient sides of the barrier. Trace Metals and Other Contaminants in the Environment, Vol 7. Boreholes are backfilled with fresh reactive material. Useful for determining the presence or absence of iron-oxidizing or sulfate-reducing bacteria.
The criteria were divided into three groups: hydraulic, mechanical and sorption. Franz-Georg Simon, Vera Biermann Mihály Csővari, József Csicsak: Uranium removal using elemental iron and hydroxiapatite in permeable reactive barriers. 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. An increase in dissolved iron indicates this reaction is occurring. Phillips and Liyuan Liang, Biogeochemical, Mineralogical, and Hydrological Characteristics of an Iron Reactive Barrier Used for Treatment of Uranium and Nitrate, Handbook of Groundwater Remediation using Permeable Reactive Barriers , 10. Sulfide By-product of sulfate reduction. Mecsek Ore, Pecs, Hungary Case Study.
It also includes the advances in the technology since the completion of the previous version of the report. Benson Evaluation of Two Strategies to Enhance the Long-Term Hydraulic Performance of Permeable Reactive Barriers , 2008. Numerous case studies are provided. Dissolved oxygen Determine whether aerobic or anaerobic conditions exist. This design guidance addresses treatability testing, design, installation, and monitoring of barrier technologies in variable geologic settings.