High Attenuation Recycled Materials as landfill liners (the HARM project) – A new concept for improved landfill liner design

This review synthesises the available published research on interactions of per- and polyfluoroalkyl substances (PFAS) with landfill liners, with the view to inform on the expected behaviour of these persistent environmental pollutants in landfills. The review addresses the nature and significant types of PFAS compounds that are destined for landfills, as well as their by-product. It discusses the known and anticipated interactions with separate landfill liner components, namely geomembranes, geosynthetic clay liners and compacted clay liners. Various water-soluble PFAS are shown to advectively transport through geosynthetic clay liners (GCL) and showcase the limitations of relying on mineral liners alone to retain PFAS. Addition of activated carbon, while increasing saturated hydraulic conductivity, significantly increases PFAS retention by the GCL and reduced PFAS flux to manageable concentrations. An assessment of the relative risk for environmental exposure of different types of PFAS from landfills through interaction with those liner components is achieved with reference to published case studies of PFAS detection in and around landfills from Australia and around the World.

Download Full-text

The role of organic attenuation in saturated clay barrier system

Water Science & Technology ◽

10.2166/wst.1996.0161 ◽

1996 ◽

Vol 33 (8) ◽

pp. 145-151 ◽

Cited By ~ 1

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.

Download Full-text

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

Canadian Journal of Civil Engineering ◽

10.1139/l94-093 ◽

1994 ◽

Vol 21 (5) ◽

pp. 872-882 ◽

Cited By ~ 7

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.

Download Full-text

HYDRAULIC CONSIDERATIONS FOR LANDFILL LINERS AND THE CHARACTERISTICS OF SOILBENTONITE MIX = Pertimbangan Hidrolik untuk Liners Landfill dan Karakteristik Campuran Tanah-Bentonit

Jurnal Teknologi Lingkungan ◽

10.29122/jtl.v14i1.1434 ◽

2016 ◽

Vol 14 (1) ◽

pp. 25

Author(s):

Alfakhur Ridlo ◽

Masami Ohtsubo

Keyword(s):

Hydraulic Conductivity ◽

Void Ratio ◽

Chemical Properties ◽

Physical Structure ◽

Hydraulic Performance ◽

Design Parameters ◽

Landfill Liner ◽

Landfill Liners ◽

Liner System ◽

Successful Design

Keberhasilan desain landfill liner membutuhkan pertimbangan yang diberikan kepada unjuk kerja hydraulic liner dari landfill. Unjuk kerja sistem hydraulic liner meliputi control laju kebocoran, waktu tempuh kontaminan melewati liner, dan attenuasi (penguatan) dari spesies kontaminan leachate. Parameter seperti ketebalan, slope, permeability, metode konstruksi dan property kimia dari material liner dapat divariasikan selama proses desain untuk memaksimalkan unjuk kerja hydraulic dari landfill liner. Efek variasi setiap komponen unjuk kerja di bahas. Unjuk kerja tiga tipe liner dibandingkan. Hasil dari perbandingan untuk membahas pentingnya parameter-parameter desain dalam penentuan unjuk kerja hydraulic dari beberapa tipe liner. Selanjutnya, berbagai macam campuran tanah dan bentonite yang dibikin compact di observasi karakteristk void ratio dan hydraulic conductivity untuk mengetahui perilaku hydraulic setelah diaplikasikan tekanan terkait dengan struktur fisik. Kata kunci :hidrolika, lempung, liner, landfill, campuran tanah-bentonite Abstract The successful design of a landfill liner requires that consideration be given to the hydraulic performance of the landfill. The hydraulic performance of a landfill liner system comprises control of leakage rate, contaminant travel time through the liner and attenuation of leachate contaminant species. Parameter such as the thickness, slope, permeability, construction method and chemical properties of liner materials can be varied during design to maximize the hydraulic performance of the landfill liner. The effect of varying each of these on the components of hydraulic performance is discussed. The hydraulic performances of three common types of liner are compared. The results of the comparison are used to discuss the importance of design parameters in determining the hydraulic performance of the different types of liner. Additionally several soil-bentonite admixture were compacted and the characteristics of void ratio and hydraulic conductivity were plotted for the understanding of their hydraulic behavior after the application of pressure with respect only for physical structure. Keywords: hydraulic, clay, liner, landfill, soil-bentonite mix

Download Full-text

Temperatures of Insulated Landfill Liner

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196153400105 ◽

1996 ◽

Vol 1534 (1) ◽

pp. 24-31 ◽

Cited By ~ 8

Author(s):

Craig H. Benson ◽

Michael A. Olson ◽

Wayne R. Bergstrom

Keyword(s):

Field Test ◽

Effective Means ◽

Landfill Liner ◽

Landfill Liners ◽

Foam Polystyrene ◽

Side Slope ◽

Leachate Collection ◽

Tire Chips

Five methods for insulating the side slope of a landfill liner were evaluated in a field test. The insulations consisted of leachate collection sand, leachate collection sand and chipped tires, polyurea foam, polystyrene boards, and encapsulated fiberglass geoinsulation panels. Results of the study indicated that tire chips are an effective means of insulating landfill liners, whereas sand alone is inadequate. Of the three geoinsulations tested, the encapsulated fiberglass and extruded polystyrene worked best. The polyurea foam performed poorly, although its performance would have been better had it been thicker. The results of the study also indicated that freezing of the liner can occur near gaps between geoinsulation panels and at corners where the panels are joined if the overlaps or seaming methods are inadequate.

Download Full-text

Effect of Compaction on Soil Physical Properties of Differently Textured Landfill Liner Materials

Geosciences ◽

10.3390/geosciences9010001 ◽

2018 ◽

Vol 9 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Steffen Beck-Broichsitter ◽

Horst Gerke ◽

Rainer Horn

Keyword(s):

Water Retention Curve ◽

Test Results ◽

Soil Hydraulic Properties ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Landfill Liner ◽

Landfill Liners ◽

Legal Standards ◽

Proctor Test ◽

Ks Values

Mineral landfill liners require legally-fixed standards including a sufficiently-high available water capacity (AWC) and relatively low saturated hydraulic conductivity values (Ks). For testing locally available and potentially suitable materials with respect to these requirements, the soil hydraulic properties of boulder marl (bm) and marsh clay (mc) were investigated considering a defined compaction according to Proctor densities. Both materials were pre-compacted in 20 soil cores (100 cm3) each on the basis of the Proctor test results at five degrees of compaction (bm1–bm5; mc1–mc5) ranging between 1.67–2.07 g/cm3 for bm and 1.09–1.34 g/cm3 for mc. Additionally, unimodal and bimodal models were used to fit the soil water retention curve near saturation and changes in the pore size distribution (PSD). The structural peak of the PSD in the fraction of pore volume between −30 and −60 hPa was more pronounced on the dry side (bm1–2, mc1–2) than on the wet side of the Proctor curve (bm4–5, mc4–5). Therefore, the loss in structural pores can be attributed to an increasing dry bulk density for bm and an increasing gravimetric moisture content during Proctor test for mc. While the mc fulfils the legal standards with AWC values between 0.244–0.271 cm3/cm3, the Ks values for bm between 1.6 × 10−6 m/s and 3.8 × 10−7 m/s and for mc between 7.4 × 10−7 m/s and 1.2 × 10−7 m/s were up to two orders of magnitude higher than required. These results suggest that the suitability of both materials as landfill liner is restricted.

Download Full-text

Recycled Materials in Geotechnics

10.1061/9780784407561 ◽

2004 ◽

Keyword(s):

Recycled Materials

Download Full-text

WISE-Tech Design

Journal for Activist Science and Technology Education ◽

10.33137/jaste.v11i1.34260 ◽

2020 ◽

Vol 11 (1) ◽

pp. 39-41

Author(s):

Avtar Judge

Keyword(s):

Recycled Materials

In this article, a student describes his development and implementation of a 'candle recycler'; that is, a device for saving melted wax and, at the same time, generating reusable candles. His invention uses recycled materials and is intended for use by people who may not have access to electric lights and/or may not have sufficient funds to purchase candles. This invention is meant as a research-informed and negotiated action to overcome harms the student perceived in relationships among fields of science & technology and societies & environments (STSE).

Download Full-text