Numerical study of strain development in high-density polyethylene geomembrane liner system in landfills using a new constitutive model for municipal solid waste

2021 ◽  
Author(s):  
Wu Gao ◽  
Edward Kavazanjian ◽  
Xuan Wu
Keyword(s):  
Constitutive Model ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
High Density Polyethylene ◽  
Numerical Study ◽  
High Density ◽  
Strain Development ◽  
Liner System

Effect of texturing on the longevity of high-density polyethylene (HDPE) geomembranes in municipal solid waste landfills

2020 ◽  
Vol 57 (1) ◽  
pp. 61-72 ◽  
Author(s):  
M.S. Morsy ◽  
R. Kerry Rowe
Keyword(s):  
Municipal Solid Waste ◽  
Crack Resistance ◽  
Solid Waste ◽  
Induction Time ◽  
High Density Polyethylene ◽  
High Density ◽  
Smooth Edge ◽  
Core Thickness ◽  
Municipal Solid Waste Landfills ◽  
Solid Waste Landfills

The effect of texturing (co-extrusion using blowing agent) on the longevity of a geomembrane (GMB) when immersed in synthetic municipal solid waste leachate is investigated over a ∼3 year period. Based on data at four temperatures (40, 55, 75, and 85 °C), the time to antioxidant depletion of the textured portion of a 1.5 mm core thickness high-density polyethylene (HDPE) GMB is 40% (standard oxidative induction time) and 9% (high-pressure oxidative induction time) faster compared to the 1.5 mm smooth edge of the GMB. However, despite this, stress crack resistance results show that texturing may have no significant effect on the time to nominal failure for this GMB. It is also shown that HDPE GMBs made from nominally the same resin but from different production lots have different rates of stress crack resistance degradation and hence time to nominal failure; this should be considered both in landfill design and landfill construction quality assurance.

Long-term performance of high-density polyethylene (HDPE) geomembrane seams in municipal solid waste (MSW) leachate

2017 ◽  
Vol 54 (12) ◽  
pp. 1623-1636 ◽  
Author(s):  
R. Kerry Rowe ◽  
Mohamad Shoaib
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Induction Time ◽  
High Density Polyethylene ◽  
High Density ◽  
Depletion Rate ◽  
The Times ◽  
Long Term Performance ◽  
Term Performance

The effect of a synthetic municipal solid waste leachate on the long-term performance of dual-wedge welds in a 1.5 mm thick high-density polyethylene geomembrane (GMB) is reported based on 4 years of testing at 40, 65, 75, and 85 °C. The effect of leachate on the GMB well away from the weld, in the heat-affected zone (HAZ) beside the weld, and in the welded zone are investigated. The slowest antioxidant depletion rate was in the weld itself and the fastest rate for the HAZ adjacent to the weld. The shear break and peel break properties started to decrease after the standard oxidative induction time had depleted to residual, but before the high-pressure oxidative induction time had reached residual. Failures occured at the HAZ adjacent to weld in both the shear and peel tests. No failure of the seam itself was observed. The times to nominal failure of the GMB in the critical HAZ are predicted. The rate of degradation in the weld and sheet are compared.

Effects of exposure conditions on the depletion of antioxidants from high-density polyethylene (HDPE) geomembranes

2002 ◽  
Vol 39 (6) ◽  
pp. 1221-1230 ◽  
Author(s):  
Henri P Sangam ◽  
R Kerry Rowe
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Induction Time ◽  
High Density Polyethylene ◽  
High Density ◽  
Accelerated Ageing ◽  
Time Intervals ◽  
Msw Landfill ◽  
Exposure Conditions

Laboratory-accelerated ageing tests have been conducted to examine the depletion of antioxidants from high-density polyethylene (HDPE) geomembranes as a result of their exposure to various environments. Samples of 2.0 mm thick geomembrane were exposed to air, water, and municipal solid waste (MSW) leachate at temperatures of 22, 40, 55, 70, and 85°C. At various time intervals, samples were collected and the oxidative induction time (OIT) was evaluated. The results indicated that the antioxidants are depleted at rates 1.6 to 2.4 times faster for samples in water than for air-exposed samples. For samples in leachate, the depletion is about 4 times faster than that in air and 1.6–3.2 times faster than that in water. Using these rates, it is estimated that if the geomembrane examined were used as an MSW landfill primary liner, it would take at least 40 years to deplete the antioxidants from the geomembrane at a temperature of 33°C and over 150 years at a temperature of 13°C.Key words: ageing, antioxidants, durability, oxidative induction time, HDPE geomembrane, antioxidant depletion time.

scholarly journals Separation of virgin plastic polymers and post-consumer mixed plastic waste by sinking-flotation technique

2021 ◽  
Author(s):  
Orlando Washinton Meneses Quelal ◽  
Borja Velázquez-Martí ◽  
Andrés Ferrer Gisbert
Keyword(s):  
Sodium Chloride ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Tap Water ◽  
Pilot Scale ◽  
Complete Separation ◽  
Plastic Waste ◽  
High Density ◽  
Low Density ◽  
Flotation Technique

Abstract The main objective of this research is to separate virgin polymers (PA, PC, PP, HDPE; PS and ABS) and post-consumer plastic waste from municipal solid waste (MSW) using the sinking-flotation technique. The separation was carried out on a pilot scale in a container of 800 l of useful volume with agitation of 160 rpm for one hour. Tap water, ethanol solutions and sodium chloride at different concentrations were used as the densification medium. The virgin polymers were separated into two groups, that is, a group of low-density polymers (HDPE and PP) and a group of high-density polymers (PS, ABS, PA, and PC). Polymers whose density was less than that of the medium solution floated to the surface, while those whose density was greater than that of the medium solution sank to the bottom. The experimental results showed that the complete separation of HDPE from PP was achieved at 23% v/v of ethanol. For the separation of the high-density polymers, up to 40% w / v sodium chloride was used. The recoveries of the polymers ranged from 70 to 99.70%. In post-consumer recycled plastic waste, fractions of 29.6% polyolefins, 37.54% PS, 11% ABS, 8% PA and 12% PC, PET and PVC were obtained. Finally, cast plates were made of the post-consumer waste to improve the identification of the type of polymer present in the separated fractions.

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