I. M. Rafizul; D. Datta
Abstract
Clay soil and their related irregular behavior such as shrinkage, swelling, desiccation cracks etc. are the main concern for the construction of composite clay liner (CCL) in waste landfill site. In this study, an investigation was conducted on a scaled model of prototype landfill liner to quantify both ...
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Clay soil and their related irregular behavior such as shrinkage, swelling, desiccation cracks etc. are the main concern for the construction of composite clay liner (CCL) in waste landfill site. In this study, an investigation was conducted on a scaled model of prototype landfill liner to quantify both the geometrical and morphological characteristics of desiccation crack of CCL. For evaluating its cracking behavior cement, Khoa Brick and fiber were used as additives for two phases of investigation. In this study, for the quantification of geometrical and morphological characteristics of desiccation crack of CCL, both the image-based algorithms on MATLAB and Image J software was performed. To evaluate additives significance on soil, surface crack ratio, average length and width of cracks, number of crack segments, crack density and others related parameters were determined. Results showed significant impact on clayed soil due to presence of various types and percentages of additives. Experiential results depicted that surface crack ratio increases with reducing water content on prototype sample and finally stabilized its propagation. For preparing CCL with clay from selected landfill site of Khulna the optimum content of additives were found 5, 5 and 1.5% for Khoa Brick, cement and polymer fiber, respectively.
A. S. M. Riyad; I. M. Rafizul; F. T. Johora
Abstract
The main focus of this study was to investigate the effect of fly ash content on the engineering properties of stabilized soils. To these attempts, two different types of fly ash, inorganic silt and Portland cement were collected. In the laboratory, the fly ash content of 10. 20 and 30%; inorganic silt ...
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The main focus of this study was to investigate the effect of fly ash content on the engineering properties of stabilized soils. To these attempts, two different types of fly ash, inorganic silt and Portland cement were collected. In the laboratory, the fly ash content of 10. 20 and 30%; inorganic silt of 10, 20 and 30% as well as cement content of 10 was used to stabilize soils. Result reveals that Atterberg limit decreases in relation to the increasing of fly ash content in stabilized soil at varying mixing proportions of fly ash content in soil. The different values of compressive strength of stabilized soils obtained from fly ash of different brand cement. In addition, the stabilized soil with cement content showed the highest value of compressive strength, whereas, stabilized soil with inorganic silt provides lowest value. The result reveals that the optimum content of fly ash was 20 and 30% for elephant and seven rings cement, respectively. The soil with organic content of 16% showed highest value of compressive strength, while, soil with organic content of 12.5% showed lowest value. Furthermore, the stabilized soils with fly ash showed comparatively the higher values of compressive strength than that of stabilized soils with inorganic silt content.
K. Fahmida; I. M. Rafizul
Abstract
The principle objective of this study was to evaluate the soil quality and the level of contamination of soil by heavy metals adapting various developed index in a selected waste disposal site at Rajbandh, Khulna, Bangladesh. To theses ...
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The principle objective of this study was to evaluate the soil quality and the level of contamination of soil by heavy metals adapting various developed index in a selected waste disposal site at Rajbandh, Khulna, Bangladesh. To theses endeavor, ten soil samples were collected from the selected locations and then the relevant elements of Al, Fe, Mn, Cr, Cu, Pb, Zn, Ni, Cd, As, Co, Sb, Sc and Hg were measured and monitored using standard method. To estimate the contamination situation of soil, contamination factor (CF), enrichment factor (EF) and geo-accumulation index (Igeo) and potential ecological risk index (PERI) were computed using geological background values. In addition, for assessing soil quality, Pearson's correlation coefficients analysis was also performed. Furthermore, this study revealed that the values of CF and Igeo in soils around the waste disposal area affected from the contamination of heavy metals mostly by Pb, Cd and Sb. In contrast, Pearson's correlation indicated that the sources of metals are almost the same and these heavy metals might be derived from the waste accumulation activity. Dump sites have great potential for energy extraction if the high valued compounds to be extracted.
I. M. Rafizul; M. Alamgir
Abstract
This study illustrates the leachate treatment efficiency based on leachate pollution index (LPI) of pre- treatment leachate as well as post-treatment leachate with chemical coagulants. Leachate samples were collected at regular intervals of time from the leachate collection chamber of the landfill lysimeter ...
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This study illustrates the leachate treatment efficiency based on leachate pollution index (LPI) of pre- treatment leachate as well as post-treatment leachate with chemical coagulants. Leachate samples were collected at regular intervals of time from the leachate collection chamber of the landfill lysimeter at KUET campus, Bangladesh to compute its pollution potential. The landfill lysimeter consists of one open dump lysimeter-A with leachate detection (A1) and collection system (A2) as well as two sanitary landfill lysimeters B and C having two different types of cap liner. The relevant parameters of leachate sample were measured in the laboratory to evaluate sub-pollution (sub-LPIs) in terms of LPI in organic pollutant (LPIor), inorganic pollutant (LPIin) and heavy metal (LPIhm) as well as the overall LPI. Moreover, the values of LPI in pre-treatment leachate were to be found 19.53, 25.33, 23.48 and 23.74 for the A1 and A2 systems of open lysimeter-A, as well as the collection systems of sanitary lysimeters- B and C, respectively. It reveals significantly the higher values than that of LPI of 5.77, 7.38 and 7.38 for the maximum leachate discharge standards of Bangladesh, India and Hong Kong, respectively. The leachate was then treated with ferric chloride (FeCl3), poly alluminum chloride (PAC), ferrus sulphate (FeSO4) and aluminum sulphate (Al2(SO4)3) in various dosages and pH values. The concentrations in post-treatment leachate by using FeCl3 at optimum dosage were to be found below the limit of maximum leachate discharge standards. Study also reveals the values of LPI of 5.32, 5.69, 5.32 and 5.24 in post-treatment leachate for the A1 and A2 systems of open lysimeter-A, as well as the collection systems of sanitary lysimeters-B and C, respectively belowthe values of LPI in leachate of maximum discharge standards. Finally, it can be concluded that differences in the level of contaminants of pre- treatment and post-treatment leachate indicated the role of leachate treatment system in minimizing the level of contaminants and lowering the risk of leachate contamination based on LPI.
