scholarly journals Clays of Different Plasticity as Materials for Landfill Liners in Rural Systems of Sustainable Waste Management

2018 ◽  
Vol 10 (7) ◽  
pp. 2489 ◽  
Author(s):  
Marcin Widomski ◽  
Witol Stępniewski ◽  
Anna Musz-Pomorska
Keyword(s):  
Hydraulic Conductivity ◽  
Environmental Sustainability ◽  
Arable Land ◽  
Saturated Hydraulic Conductivity ◽  
Compacted Clay ◽  
Landfill Liners ◽  
Environmental Threats ◽  
Waste Landfill ◽  
Drying And Rewetting ◽  
Basic Characteristics

This paper presents a study assessing the possible application of seven clay substrates of various particle compositions and plasticity, sampled locally in rural regions, as materials allowing affordable construction of the waste landfill liners, which meet the main principles of sustainability, utilize locally available materials and limit the environmental threats posed by landfill leachate to water, public health and arable land. The researched substrates were tested according to their long-term sealing properties by their saturated hydraulic conductivity after compaction, swelling and shrinkage characteristics and ability to sustain their sealing capability after repeated drying and rewetting. The basic characteristics of soils were determined by the standard methods. Saturated hydraulic conductivity after compaction and after repeated shrinking and swelling were tested in laboratory falling head permeameters. Shrinkage characteristics were based on dimensionless indicators of the geometry and linear extensibility. The obtained results showed that the tested clay substrates were found applicable to construction of compacted clay liner for sustainable waste landfill. The environmental sustainability of a local, rural waste landfill, isolated by compacted earthen liners utilizing local materials is, in our opinion possible, but strongly related to the compaction parameters applied during liner construction for the given clay substrate.

scholarly journals Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

2021 ◽  
Vol 13 (13) ◽  
pp. 7301
Author(s):  
Marcin K. Widomski ◽  
Anna Musz-Pomorska ◽  
Wojciech Franus
Keyword(s):  
Hydraulic Conductivity ◽  
Exchange Capacity ◽  
Saturated Hydraulic Conductivity ◽  
Clay Soils ◽  
Compacted Clay ◽  
Clay Liner ◽  
Compacted Clay Liner ◽  
Drying And Rewetting ◽  
Swelling Characteristics ◽  
Shrinkage And Swelling

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

scholarly journals Shrink-swell potential, hydraulic conductivity and geotechnical properties of clay materials for landfill liner construction

2015 ◽  
Vol 29 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Marcin K. Widomski ◽  
Witold Stępniewski ◽  
Rainer Horn ◽  
Andrzej Bieganowski ◽  
Lucjan Gazda ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Particle Density ◽  
Total Porosity ◽  
Saturated Hydraulic Conductivity ◽  
Landfill Liner ◽  
Angle Of Internal Friction ◽  
Drying And Rewetting ◽  
Swell Potential ◽  
Basic Characteristics ◽  
Clay Materials

Abstract This paper presents studies concerning the applicability of two clay materials for the construction of a sustainable landfill liner. The studies consisted in determination of basic characteristics of the materials, eg particle size distribution, bulk density, particle density, total porosity, pore size, mineralogy, specific surface area, nanoparticle size, and Atterberg limits, as well as measurements of their geotechnical and hydraulic parameters, such as in situ saturated hydraulic conductivity, modules of primary and secondary compression, cohesion, and angle of internal friction. Furthermore, the effects of compaction performed by the Proctor method at various water contents on swelling and shrinkage characteristics and saturated hydraulic conductivity were investigated in order to determine the compliance with the national requirements for selection of material for landfill liner construction. The determined characteristics and geotechnical parameters of the tested clay materials allowed qualifying them as suitable for municipal landfill construction. The shrinkage potential of the tested clays observed was rated as moderate to very high. The cyclic drying and rewetting of the clay materials performed resulted in a significant increase in saturated hydraulic conductivity. Thus, the clay sealing layers, as part of a multilayer liner, should be very carefully operated, preventing the drying out of the clay sealing and assuring the possibility of its constant saturation.

Global Mapping of Soil Saturated Hydraulic Conductivity Combining Legacy Data, Spatial Covariates and Machine Learning

2021 ◽  
Author(s):  
Surya Gupta ◽  
Peter Lehmann ◽  
Andreas Papritz ◽  
Tomislav Hengl ◽  
Sara Bonetti ◽  
...  
Keyword(s):  
Machine Learning ◽  
Hydraulic Conductivity ◽  
Cross Validation ◽  
Arable Land ◽  
Remotely Sensed ◽  
Saturated Hydraulic Conductivity ◽  
Pedotransfer Functions ◽  
Data Set ◽  
Global Database ◽  
Spatially Distributed

<p>Saturated soil hydraulic conductivity (Ksat) is a key parameter in many hydrological and climatic modeling applications, as it controls the partitioning between precipitation, infiltration and runoff. Values of Ksat are often deduced from Pedotransfer Functions (PTFs) using maps of soil attributes. To circumvent inherent limitations of present PTFs (heavy reliance of arable land measurements, ignoring soil structure, and geographic bias to temperate regions), we propose a new global Ksat map at 1–km resolution by harnessing technological advances in machine learning and availability of remotely sensed surrogate information (terrain, climate and vegetation). We compiled a comprehensive Ksat data set with 13,258 data geo-referenced points from literature and other sources. The data were standardized and quality-checked in order to provide a global database of soil saturated hydraulic conductivity (SoilKsatDB). The SoilKsatDB was then applied to develop a Covariate-based GeoTransfer Function (CoGTF) model for predicting spatially distributed Ksat values using remotely sensed information on various environmental covariates. The model accuracy assessment based on spatial cross-validation shows a concordance correlation coefficient (CCC) of 0.16 and a root meansquare error (RMSE) of 1.18 for log10 Ksat values in cm/day (CCC=0.79 and RMSE=0.72 for non spatial cross-validation). The generated maps of Ksat represent spatial patterns of soil formation processes more distinctly than previous global maps of Ksat based on soil texture information and bulk density. The validation indicates that Ksat could be modeled without bias using CoGTFs that harness spatially distributed surface and climate attributes, compared to soil information based PTFs. The relatively poor performance of all models in the validation (low CCC and high RMSE) highlights the need for the collection of additional Ksat values to train the model for regions with sparse data.</p>

The role of organic attenuation in saturated clay barrier system

1996 ◽  
Vol 33 (8) ◽  
pp. 145-151 ◽  
Author(s):  
Irene M. C. Lo
Keyword(s):  
Hydraulic Conductivity ◽  
Concentration Gradient ◽  
Organic Contaminants ◽  
Molecular Diffusion ◽  
Pollution Prevention ◽  
Fickian Diffusion ◽  
Compacted Clay ◽  
Landfill Liner ◽  
Landfill Liners ◽  
Saturated Clay

A review of literature finds that advection, diffusion, and retardation are the main processes that govern the migration of organic contaminants through compacted clay landfill liners. However, much emphasis is placed on the hydraulic conductivity in the specification for landfill liner design. It is misunderstood that if the hydraulic conductivity of the clay is low, then the liner must provide an adequate barrier for groundwater pollution prevention. Unfortunately, even the advection is minimal, contaminants can migrate through clay by simple Fickian diffusion at a rate that can be significant. The process of diffusion is mainly dependent on the concentration gradient between the leachate and the groundwater. If a clay lining system is installed, the only way to reduce the effect of diffusion is to reduce the concentration gradient by pollutant retardation. In this paper, the relative importance of molecular diffusion and advection, and the effect of pollutant retardation on the advective and diffusive transport are discussed using a conceptual-mathematical model. Based on a review of organic contaminant attenuation by clay liners, a guideline on the development of a high organic attenuation engineered barrier as a second line of defence for containment sites is proposed.

Statistical analyses of compacted clay landfill liners. Part 1: model development

1994 ◽  
Vol 21 (5) ◽  
pp. 872-882 ◽  
Author(s):  
Scott B. Donald ◽  
Edward A. McBean
Keyword(s):  
Hydraulic Conductivity ◽  
Geometric Mean ◽  
Model Development ◽  
Statistical Analyses ◽  
Compacted Clay ◽  
Clay Liners ◽  
Landfill Liner ◽  
Landfill Liners ◽  
Clay Liner ◽  
Spatial Correlation Structure

The acceptance of compacted clay liners, from a management point of view, has been a source of major concern because of the uncertainty associated with the hydrogeologic properties of the clay. By examining the flux of leachate through the compacted clay liner of a typical engineered landfill, where the hydraulic conductivity of the clay is represented by a stochastic process, an acceptance protocol suitable for compacted clay landfill liners is derived. Determination of the equivalent hydraulic conductivity of the clay liner is accomplished by comparing the flux of leachate through a homogeneous representation of the clay with the flux obtained by Monte Carlo analyses. Acceptance criteria are subsequently developed based on a statistical technique which calculates the confidence limits about a percentile of a probability distribution as well as about the mean of the distribution. For the landfill configuration simulated, the results indicate that the hydraulic conductivity of a compacted clay landfill liner follows a lognormal distribution and exhibits virtually no spatial correlation structure. In addition, for liners exhibiting a geometric mean conductivity of 10−7 cm/s and a standard deviation of 0.3, the geometric mean value is a conservative estimate of the hydraulic conductivity of the clay, provided the liner is constructed in a series of four 150 mm lifts. Key words: clay liners, hydraulic conductivity, statistical analyses, latin hypercube, equivalent hydraulic conductivity.

Influence of different vegetation types on saturated hydraulic conductivity in alluvial topsoils

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Andrej Halabuk
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Water Transport ◽  
Mutual Influence ◽  
Arable Land ◽  
Transport Processes ◽  
Saturated Hydraulic Conductivity ◽  
Vegetation Types ◽  
Undisturbed Soil ◽  
Mean Values

AbstractIn the Paríž creek catchment (southwestern part of Slovakia), the influence of different vegetation types on selected soil properties in alluvial topsoils was studied. Specifically, the effect on saturated hydraulic conductivity considered as indicator of water transport process and the effect on soil bulk density considered as indicator of soil structure were analysed. Due to the mutual influence of plant roots on soil properties, the root biomass was also estimated and its relationship to the studied soil properties was explored. Reed and tall-sedge wetlands and alluvial wet meadows represented the studied vegetation types. Adjacent arable lands (former grasslands) with corn were included for comparison. In total, 64 samples were used for comparative analysis. A standard methodology for measurement of the saturated hydraulic conductivity, the so-called falling head technique was used on 250 cm3 soil cores. Undisturbed soil samples were taken from the depth of 5 cm. Analysis of variance, mutual comparison of mean values and correlation matrix were used for statistical analyses. Measurements showed significantly higher values of saturated hydraulic conductivity for topsoils in wetlands (6.2 m day−1 on average) compared to mown grasslands (1.47 m day−1) and arable land (0.79 m day−1). The results indicated a specific significance of wetlands in relation to water transport processes in alluvial topsoils.

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