Effects of freezing and thawing on the hydraulic conductivity of paper mill sludges used as landfill covers

1996 ◽  
Vol 33 (5) ◽  
pp. 783-792 ◽  
Author(s):  
Horace K Moo-Young, Jr. ◽  
Thomas F Zimmie
Keyword(s):  
Hydraulic Conductivity ◽  
Paper Mill ◽  
Paper Sludge ◽  
Compacted Clay ◽  
Freezing And Thawing ◽  
Thin Sections ◽  
Shrinkage Cracks ◽  
Compacted Clays ◽  
Landfill Covers ◽  
Study Laboratory

A major concern in the design of landfill covers and liners that use compacted clays as the hydraulic barrier is freezing and thawing. Paper mill sludges have been used in landfill covers to subtitute for clays as the hydraulic barrier. In this study, laboratory-compacted paper sludges have been subjected to one-dimensional and three-dimensional laboratory freezing and thawing cycles. Freezing and thawing increased the hydraulic conductivity of the paper sludges about one to two orders of magnitude. To determine why freezing and thawing cause an increase in hydraulic conductivity, an evaluation of the effects of freezing and thawing on the macrostucture of paper sludges was conducted. Frozen thin sections of paper sludges were prepared after freeze–thaw cycling and were compared to frozen thin sections of a compacted clay. Macrostructure analysis of the paper sludge and clay thin sections was conducted by using back lighting to reveal the details of ice structure. Analysis of the clay thin sections revealed ice lenses and shrinkage cracks. Ice lenses and shrinkage cracks in sludge thin sections were difficult to determine when the same procedure for compacted clays was used. Key words: freeze, paper sludge, landfill, permeability, macrostructure, thin sections.

Effect of freeze–thaw on the hydraulic conductivity and morphology of compacted clay

1993 ◽  
Vol 30 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Majdi A. Othman ◽  
Craig H. Benson
Keyword(s):  
Hydraulic Conductivity ◽  
Three Dimensional ◽  
Compacted Clay ◽  
Clay Liners ◽  
Overburden Pressure ◽  
Thin Sections ◽  
Freeze Thaw ◽  
State Of Stress ◽  
Soil Liners ◽  
Compacted Clays

Several studies have shown that freeze–thaw causes changes in the hydraulic conductivity of compacted clays. Cracks formed by ice lensing and shrinkage cause the hydraulic conductivity to increase. In this paper, changes in hydraulic conductivity are related to changes in morphology. Photographs of thin sections of frozen specimens show that ice lenses form in compacted clay during freezing in a closed system. Photographs also show that similar ice structures are obtained for one- and three-dimensional freezing, which explains why similar hydraulic conductivities are obtained for both conditions. The photographs also show that a significant network of cracks forms in a single cycle of freeze–thaw. With additional cycles, new ice lenses are created and thus the hydraulic conductivity continues to increase. However, after about three cycles the number of new ice lenses becomes negligible and hence further changes in hydraulic conductivity cease. The temperature gradient and state of stress affect morphology and hydraulic conductivity of compacted clays subjected to freeze–thaw. At larger temperature gradients, more ice lenses form and hence the hydraulic conductivity increases. In contrast, application of overburden pressure inhibits the formation of ice lenses and reduces the size of the cracks remaining when lenses thaw. As a result, the hydraulic conductivity is reduced. Key words : compacted clay, hydraulic conductivity, clay liners, soil liners, freeze-thaw, ice lenses, structure.

Remarks on the design of clay liners used in lagoons as hydraulic barriers

1992 ◽  
Vol 29 (3) ◽  
pp. 512-515 ◽  
Author(s):  
S. Leroueil ◽  
J. P. Le Bihan ◽  
R. Bouchard
Keyword(s):  
Hydraulic Conductivity ◽  
Key Words ◽  
Water Content ◽  
Compacted Clay ◽  
Plastic Limit ◽  
Clay Liners ◽  
Natural Soils ◽  
Compacted Clay Liner ◽  
Compacted Clays ◽  
Hydraulic Barriers

Considering that (i) the hydraulic conductivity of compacted clays is smaller on the wet side of optimum; (ii) the plastic limit is the water content below which the soil develops fissures under small stresses; (iii) the plastic limit and the optimum standard Proctor water content are similar for many natural soils; and (iv) the strength of compacted clays, thus the limit of trafficability, is a function of (w – wopt)/Ip, relevant conditions for the design of clay liners and the evaluation of their hydraulic conductivity are proposed. Key words : compacted clay, liner, hydraulic conductivity, strength, design.

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.

Hydraulic conductivity and removal rate of compacted clays permeated with landfill leachate

2013 ◽  
Vol 51 (31-33) ◽  
pp. 6148-6157 ◽  
Author(s):  
Mehmet Sukru Ozcoban ◽  
Nejat Cetinkaya ◽  
Suna Ozden Celik ◽  
Guler Turkoglu Demirkol ◽  
Vildan Cansiz ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Landfill Leachate ◽  
Removal Rate ◽  
Compacted Clays

Design of Landfill Covers Using Paper Mill Sludges

1995 ◽  
pp. 14-28
Author(s):  
Horace K. Moo-Young ◽  
Thomas F. Zimmie
Keyword(s):  
Paper Mill ◽  
Landfill Covers

THE EFFECTS OF SLOPE POSITION AND CROPPING SEQUENCE ON SOIL PHYSICAL PROPERTIES IN PRINCE EDWARD ISLAND

1988 ◽  
Vol 68 (4) ◽  
pp. 763-774 ◽  
Author(s):  
LINNELL M. EDWARDS
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Prince Edward Island ◽  
Soil Depth ◽  
Aggregate Stability ◽  
Penetration Resistance ◽  
Slope Position ◽  
Bottom Slope ◽  
Freezing And Thawing ◽  
Freeze Thaw

Soil physical characteristics were examined at depth intervals of 0–15 and 15–30 cm over three slope positions (top-, mid-, and bottom-slope) for three cropping sequences (hay-barley, cereals-barley, and potato-barley). Hydraulic conductivity was a significant (P ≤ 0.05) 40–50% greater at top-slope than mid- or bottom-slope, and aggregate stability percentage was a significant 6–7% greater at bottom-slope than mid- or top-slope when the soil aggregates were pretreated by freezing and thawing (freeze/thaw). Under the potato-barley sequence shear strength, penetration resistance and bulk density were significantly greater than any other sequence by up to 29, 21 and 15%, respectively; while hydraulic conductivity and maximum penetration depth were, respectively, up to 65 and 28% lower than any other sequences. Under hay-barley, hydraulic conductivity and aggregate stability (freeze/thaw) were, respectively, up to a significant 82 and 10% greater than any other sequence. There was, therefore, significantly more compaction under potato-barley and more soil physical enhancement under hay-barley than other respective sequences. Disease severity was up to 55% greater at bottom-slope than at mid-slope or top-slope for Birka barley, which also showed a significant linear decrease (r2 = 0.89) in yield with increasing shear strength. Yield of Perth barley showed a significant linear increase with increasing soil depth (r2 = 0.92) and clay-silt content (r2 = 0.78). Key words: Aggregate stability (freeze/thaw), crop rotation, penetration resistance, shear strength, barley, potatoes, hay

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