Utilization of bagasse ash in the compacted clay liner
01 Jan 2020-Vol. 89, pp 297-302
TL;DR: In this article, a study was carried out to assess the stabilization of compacted clay liners with bagasse ash, and it was observed that 40% of the fly ash can be mixed with bentonite so that the essential requirements of the liner are maintained.
Abstract: Landfills are highly engineered waste containment systems, designed to minimize the impact of waste on the environment. In modern landfills, the waste is contained by liner and cover systems. Due to the scarcity of natural clay, the commercially available bentonite is often used in the construction of liners. The bentonite layer generally shrinks during the summer, and therefore, severe cracks are formed; thus, it fails to control the migration of leachate. In the past, various additives have been used to stabilize bentonite. In recent years, studies have been focused on using reactive materials as additives so that they can stabilize bentonite, and also, it can adsorb the heavy metals from the leachates. The sugar industry produces fly ash, known as the bagasse ash, which causes a disposal problem. This bagasse ash is found to be a good absorbent material. Hence, a study was carried out to assess the stabilization of compacted clay liner blended with bagasse ash. Several tests, including consistency limits and hydraulic conductivity tests, have been performed by blending different contents of bagasse ash. From the test results and their analysis, it is observed that 40% of bagasse ash can be mixed with bentonite so that the essential requirements of the liner are maintained.
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TL;DR: In this article, the hydraulic conductivity of geosynthetic clay liners (GCLs) permeated with non-standard liquids (i.e., liquids other than water) is discussed and supported with test data.
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TL;DR: In this article, Bagasse fly ash, a waste produced in sugar industries, has been converted into an inexpensive and effective adsorbent, which has been used for the removal of copper and zinc from wastewater.
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TL;DR: Test results indicate that in terms of the physical properties, most of the data fall within narrow ranges, although data from the copper/aluminum-based WFS samples might fall beyond the ranges, and material leaching analyses indicate that the toxicity of WFS flowable fills is below regulated criteria.
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TL;DR: In this paper, the substitution of attapulgite clay for bentonite in an otherwise sand-bentonite (S-B) mixture will improve the resistance to change in hydraulic conductivity of the mixture upon permeation with calcium chloride (CaCl\d2) solutions relative to a processed tap water.
Abstract: The hypothesis that the substitution of attapulgite clay for bentonite in an otherwise sand-bentonite (S-B) mixture will improve the resistance to change in hydraulic conductivity of the mixture upon permeation with calcium chloride (CaCl\d2) solutions relative to permeation with a processed tap water is tested. For mixtures with the same clay soil content, complete substitution of attapulgite clay for bentonite significantly decreases the change in hydraulic conductivity relative to that observed for the S-B mixtures upon permeation with a 0.5 M CaCl\d2 solution. In addition, the resistance to change in hydraulic conductivity of the sand-attapulgite clay-bentonite (S-AC-B) mixtures containing 20% clay soil is improved by increasing the percentage of attapulgite clay in the clay soil admixture from 50% to 100% and by decreasing the concentration of the CaCl\d2 solution from 0.5 M to 0. The first exposure effect also decreases with increasing amount of attapulgite clay in S-AC-B mixtures containing 20% clay soil. However, the resistance to change in hydraulic conductivity resulting from substituting only half of the bentonite in the S-B mixtures with an equal amount of attapulgite clay is not improved substantially due to the dominating influence of the bentonite portion of the sand-clay mixture.
74 citations
TL;DR: In this article, the potential use of sand-attapulgite (palygorskite) mixtures as a landfill liner was investigated and the results showed that the addition of clay developed coating between and around the sand grains which results in filling the voids and reducing the hydraulic conductivity of the sand-clay mixtures.
Abstract: This paper investigates the potential use of sand–attapulgite (palygorskite) mixtures as a landfill liner. The sand and attapulgite clay used in this study were brought from Wahiba (eastern Oman) and Al-Shuwamiyah (southern Oman), respectively. Initially the basic properties of the sand and clay were determined. Then the attapulgite clay was added to the sand at 5, 10, 20 and 30% by dry weight of the sand. The sand–attapulgite clay mixtures were subjected to mineralogical, chemical, microfabric and geotechnical analyses. The X-ray diffraction (XRD) qualitative analysis showed that attapulgite is the major clay mineral. The chemical compounds, exchangeable cations and cation exchange capacity (CEC) for the␣samples were determined. The CEC for the sand–clay mixtures is low but increases with the increase in clay content. The scanning electron microscope (SEM) examination showed that the addition of clay developed coating between and around the sand grains which results in filling the voids and reducing the hydraulic conductivity of the sand–clay mixtures. The hydraulic conductivity values for the pure clay and sand + 30% clay mixture prepared at 2% above optimum water content are slightly higher than hydraulic conductivity requirements for landfill liners but can be acceptable. The geotechnical study which included grain size distribution, Atterberg limits, specific gravity, compaction, hydraulic conductivity and shear strength tests showed that the sand+30% clay mixture prepared at 2% above optimum water content can be considered to satisfy the requirements for landfill liners. For all sand–clay mixtures no swelling was recorded and the addition of clay to the sand improved the shear strength.
22 citations