Download or read book Compatibility of Geosynthetic Clay Liners with Leachate from CCP Management Facilities written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were conducted to evaluate whether coal combustion product (CCP) leachates adversely affect the hydraulic conductivity (K) of geosynthetic clay liners (GCLs) as an alternative material in lieu of a compacted clay liner (CCL). Chemical properties of CCP leachates were compiled based on a nationwide survey of CCP disposal facilities. Five synthetic leachates were developed to represent a range of conditions encountered in CCP disposal facilities: typical CCP leachate, strongly divalent cation fly ash leachate, flue gas desulfurization (FGD) residual leachate, high ionic strength ash leachate, and trona ash leachate. Nine GCLs were tested: two Na-bentonite (NaB) GCLs, six bentonite-polymer (P-B) GCLs, and one bentonite polymer composite (BPC). Hydraulic conductivity tests on GCLs were conducted on prehydrated (60-d on subgrade soil or DI water) and non-prehydrated GCL specimens. Tests were run to hydraulic and chemical equilibrium at effective stresses of 20 kPa, and then higher effective stresses were applied up to 450 kPa. At 20 kPa, the GCLs with NaB had high hydraulic conductivity to CCP leachates (10-10 to 10-6 m/s). Hydraulic conductivity was directly proportional to the ionic strength of the leachate and inversely proportional to the swell index of the bentonite when hydrated in leachates. The hydraulic conductivity of B-P GCLs with low polymer loading (d"1.2%) behaved similarly to NaB GCLs. However, the hydraulic conductivity of GCLs with polymer loading e"1.9 % is controlled by the clogging behavior of polymer hydrogel. Polymer elution was observed during the hydraulic conductivity tests, and increasing hydraulic conductivity was associated with cumulative polymer elution. Increasing the effective stress from 20 to 450 kPa caused the hydraulic conductivity to decrease by up to three orders of magnitude. At 450 kPa effective stress, the hydraulic conductivities of all tests were lower than 10-9 m/s except for one test with Trona leachate. This observation indicates that high effective stress can minimize the effect of CCP chemistry on the hydraulic behavior of GCLs. Subgrade hydration had no beneficial effect on hydraulic conductivity; however, prehydration with DI water can effectively protect the GCLs due to a large amount of immobile water retained in the bentonite

Download or read book Compatibility of Geosynthetic Clay Liners with Acidic Solutions written by Yang Liu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosynthetic clay liners (GCLs) are widely used as hydraulic barriers because of their sealing capacity in contact with water. However, with the increasing interest in their use in mining applications, the compatibility issues of GCLs to mining leachates are of some concern. This research work has been undertaken to enhance our understanding of compatibility of GCLs with strong acidic leachates, as for example, which may occur in mining leachates. Three types of bentonites were selected for this research program. Tests included index tests such as Atterberg limits, swell index, fluid loss and suspension rheology under various concentrations of sulfuric acid solutions. The results indicate that all index parameters degraded when the materials were exposed to acidic solutions. The degradation of these indices would indicate a high probability for the degradation of hydraulic performance of GCLs to occur based on established correlations between hydraulic conductivity and these indices. The mineralogical analyses on bentonite components of GCLs before and after reaction with sulfuric acid solutions were conducted using X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The dissolution of bentonite, loss of water from smectite interlayers, and the collapse of smectite layers were observed using these methods, these observations explained in part the degradation of the engineering indices and hydraulic performance of bentonites or GCLs. A series of flexible-wall permeameter tests were conducted to directly evaluate the hydraulic performance of GCLs when subjected to different concentrations of sulfuric acid solutions. Effective stress and prehydration condition, both of which can affect the hydraulic performance, were also considered. The hydraulic conductivity was observed to increase with increasing sulfuric acid concentration, but specimens prehydrated with water had lower resulting hydraulic conductivity to sulfuric acid leachates than non-prehydrated specimens. Higher applied effective stress tended to decrease the hydraulic conductivity presumably by compressing the specimens thereby resulting in smaller hydraulically active pores. Three powdered polymers, having either negative, positive or neutral charges, were used in this study to determine whether the hydraulic performance of bentonites under acidic conditions could be improved. Any improvements achieved were only observed under deionized water and low sulfuric acid concentration (≤0.015 M). Generally, no significant differences in test parameters caused by the polymer types (cationic, non-ionic and anionic) were observed under DI water and low sulfuric acid concentration (≤ 0.015 M). However, at higher acid concentrations, these polymers tended to lose effectiveness due probably to pH induced changes in polymer conformation, from presumably elongation to aggregate, at the clay surface. Sulfuric acid is detrimental to the hydraulic performance of GCLs, even if GCLs are prehydrated with good quality water. With better knowledge of how GCLs behave under strong acidic conditions, the geotechnical engineering community will be better equipped to approach and resolve potential problems involving interaction between GCLs and acidic solutions.

Download or read book Advances in Geosynthetic Clay Liner Technology written by Robert E. Mackey and published by ASTM International. This book was released on 2004 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soon after the inception of ASTM D35.04 Subcommittee on Geosynthetic Clay Liners, the first symposium on Testing and Acceptance Criteria for Geosynthetic Clay Liners (GCLs), STP 1308, was held on 29 January 1996, in Atlanta, Georgia. The intention of the symposium was to bring together the current knowledge and understanding regarding this relatively new product used in containment systems. Since that symposium, numerous GCL standards have been developed along with a greater appreciation of the product's capabilities and limitations. ASTM D35 determined it was time to assess the current state of GCL technology to better address possible revisions of the present ASTM GCL standards and determine what new standards will be required in the future.

Download or read book Geosynthetic Clay Liners in Alkaline Environments written by JA. McKelvey and published by . This book was released on 1997 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of geosynthetic clay liners (GCLs) as secondary barrier layers in environmental applications such as landfills and other impoundment facilities is becoming increasingly more popular among the engineering community, particularly at project sites where earthen materials suitable for barrier layers may not be locally available. Design engineers for these environmental applications are becoming well versed at performing equivalency calculations comparing the performance of geosynthetic materials to their earthen counterparts. For barrier layers, these equivalency calculations would normally compare the mechanical and hydraulic properties of the GCL to a compacted clay liner. Of these properties, the ability of the hydraulic properties to withstand degradation due to permeation of contained leachates is of prominent concern. Such is the case in alkaline environments. The leachate may adversely affect the GCL by minimizing swelling, decreasing adsorption capacity and increasing the permeability of the material. If the effect on the material is significant, the usefulness of this product is diminished, possibly voiding any equivalency comparison to compacted clay liner performance. The design engineer must fully understand what effect, if any, specific leachates will have on the GCL being considered. Accordingly, appropriate performance testing with the leachate in question must be performed during the design phase and confirmed during construction through quality assurance testing.

Download or read book Compatibility of Geosynthetic Clay Liners GCLs with Multi species Inorganic Solutions written by Dale Christian Kolstad and published by . This book was released on 2000 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Testing and Acceptance Criteria for Geosynthetic Clay Liners written by Larry W. Well and published by ASTM International. This book was released on 1997 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: An engineering perspective on the liners, which are used as barriers for containing liquid and in conjunction with geomembranes in landfills and capping systems. Explore aspects of testing for shear strength and long-term creep, issues and methods of testing for hydraulic conductivity, and specifica

Download or read book Geosynthetic Clay Liners for Waste Containment Facilities written by Abdelmalek Bouazza and published by CRC Press. This book was released on 2009-11-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasingly stringent regulation of pollution and waste production worldwide drives the need to isolate contaminants that pose a threat to human and environmental health by using engineered barrier systems involving the use of low permeable materials. Over the past two decades, geosynthetic clay liners have gained widespread acceptance for use in such barrier systems. They are often used as a component of primary and secondary base liners or final cover systems in municipal solid-waste landfills as well as in regulated industrial storage and mining waste-disposal facilities. This book gives a comprehensive and authoritative review of the current state of practice on geosynthetic clay liners in waste containments. It provides an insight into individual materials (bentonite and the associated geosynthetics) and the manufacturing processes. This is followed by the coverage of important topics such as hydraulic conductivity, chemical compatibility, contaminant transport, gas migration, shear strength and slope stability, and field performance.

Download or read book Evaluation of the Long Term Effect of Inorganic Leachate on Geosynthetic Clay Liners written by Darwish El-Hajji and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Because of its low permeability and high swelling characteristics, bentonite is used in various hydraulic barrier systems and in the manufacturing of Geosynthetic Clay Liners (GCLs). Exposure to inorganic solutions containing elevated concentrations of electrolyte can significantly increase their permeability. To enhance the bentonite's chemical resistance to inorganic solutions, the manufacturers of GCL materials introduced propriety soluble polymeric compounds as an additive to bentonite. The resulting materials are referred to as polymer-treated, chemically-enhanced, or contaminant-resistant clays, and are arguably resistant to a host of inorganic chemicals. In this study, the response of both regular and polymer treated bentonite clays to ordinary tap water and inorganic landfill leachate is evaluated using permeability tests, index tests and x-ray diffraction. The results indicate the high dependence of performance on sample preparation techniques, pre-hydration conditions, and first wetting liquid and, to a lesser extent, polymer treatment. The x-ray diffraction results indicate that the samples reached chemical equilibrium during the permeation process, as demonstrated by a full shift in d-spacing from Na-bentonite to Ca-bentonite. Further, the results show that the cation exchange capacity, the clay plasticity ratio, and the swell index appear to be reliable indicators of the hydraulic compatibility of bentonite permeated with inorganic chemicals.

Download or read book Methods for Testing the Compatibility of Clay Liners with Landfill Leachate written by JJ. Bowders and published by . This book was released on 1985 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compatibility of compacted clay liners with landfill leachate may be evaluated with laboratory permeability tests. Compaction mold permeameters are recommended for laboratory-compacted specimens of clay subjected to low overburden pressure. Flexible wall permeameters are recommended for laboratory-compacted specimens subjected to relatively high overburden pressure and for undisturbed specimens of clay obtained from the field. Before permeability tests are performed, the index properties of the soil should be determined by mixing the soil with water and by mixing the soil with the leachate. If the leachate does not affect the index properties of the soil, it is not likely to affect the permeability. The solubility of the soil in the leachate should be checked if the soil is acidic or basic. Also, for dilute leachates, batch equilibrium tests are recommended before a permeability test is initiated so that the tendency for the soil to adsorb materials in the leachate can be evaluated. The effluent liquid should be monitored to determine the degree of breakthrough of key constituents. It is best to continue the permeability test until full breakthrough is achieved.

Download or read book Geosynthetic Clay Liners for Waste Containment Facilities written by and published by . This book was released on 2010 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Initial Hydration Conditions on GCL Leachate Permeability written by L. Comeaga and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern landfill liners typically contain several geosynthetics and natural omponents integrated into a system whose primary function is the containment of waste and leachate. One of these hydraulic barrier components is represented by Geosynthetic Clay Liners (GCL). The GCLs are factory manufactured hydraulic barriers consisting of bentonite clay supported by geotextiles or geomembranes. Since the waterproofing function is assured by the bentonite clay it is therefore advisable to verify its chemical compatibility with the leachate and its effect upon the hydraulic conductivity value. According to the climatic situations occurring between the GCLs and waste installation, the leachate exposure moment can correspond to various GCLs hydration degrees. In this context, this paper aims at analyzing the total or partially hydrated GCL's behavior after a long time exposure to leachate. The permeability tests carried out for two needle-punched GCLs in three situations (saturated with water, water partially hydrated and saturated with leachate) show an important variation of the permeability with the hydration degree.

Download or read book Water in Road Structures written by Andrew Dawson and published by Springer Science & Business Media. This book was released on 2008-10-21 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Only book world-wide addressing this topic. The principal output of the European co-operative Action on "Water Movements in Road Pavements & Embankments". Provides unique guidance on assessing water condition and its affects on road performance. Provides unique guidance on assessing and ameliorating contaminant movement in pavement groundwater. Written by leading experts in Europe.

Download or read book Geo Congress 2014 Technical Papers written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solid Waste Landfilling written by Raffaello Cossu and published by Elsevier. This book was released on 2018-11-29 with total page 1190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid Waste Landfilling: Concepts, Processes, Technology provides information on technologies that promote stabilization and minimize environmental impacts in landfills. As the main challenges in waste management are the reduction and proper treatment of waste and the appropriate use of waste streams, the book satisfies the needs of a modern landfill, covering waste pre-treatment, in situ treatment, long-term behavior, closure, aftercare, environmental impact and sustainability. It is written for practitioners who need specific information on landfill construction and operation, but is also ideal for those concerned about the possible return of these sites to landscapes and their subsequent uses for future generations. Includes input by international contributors from a vast number of disciplines Provides worldwide approaches and technologies Showcases the interdisciplinary nature of the topic Focuses on sustainability, covering the lifecycle of landfills under the concept of minimizing environmental impact Presents knowledge of the legal framework and economic aspects of landfilling

Download or read book Proceedings of the 8th International Congress on Environmental Geotechnics Volume 3 written by Liangtong Zhan and published by Springer. This book was released on 2018-10-10 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers selected papers presented at the 8th International Congress on Environmental Geotechnics (ICEG), held on October 28 - November 1, 2018 in Hangzhou, China. The theme of the congress is “Towards a Sustainable Geoenvironment”, which means meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Under this theme, the congress covers a broad range of topics and provides an excellent opportunity for academics, engineers, scientists, government officials, regulators, and planners to present, discuss and exchange notes on the latest advances and developments in the research and application of environmental geotechnics.

Download or read book Hydraulic Conductivity and Waste Contaminant Transport in Soil written by David Edwin Daniel and published by ASTM International. This book was released on 1994 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Urban Infrastructure and Governance written by G Ramesh and published by Taylor & Francis. This book was released on 2020-11-29 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book contains a selection of papers on urban governance in its multiple perspectives. It has evolved from the presentations made at the Third International Conference on Public Policy and Management held in 2008.The topics are grouped into several themes: Urban Plan and Governance, Urban Governance through Partnership and Participation, and Financing Urban Infrastructure. With several examples from developing nations, the book dwells into the practical and managerial aspects of urban planning, partnerships, participation, financial mobilization and effective governance. One of the highlights of the book is that it looks at financial mobilization as a strategy for governance and how the financial system in itself can be an instrument of governance.