Ponlayuth Sooksamiti

Single and binary adsorption of Cd (II) and Zn (II) ions from aqueous solutions onto bottom ash

Bottom ash, a waste obtained from coal-burning power plant, was used as a low cost adsorbent for the removal of Cd (II) and Zn (II) ions from single and binary systems in batch experiments. The results of adsorption capacity showed that bottom ash could be considered as a potential adsorbent. The uptake of Zn (II) ion was greater than that of Cd (II) ion. For single adsorption, based on the correlation coefficient (R2) values, both Langmuir and Freundlich isotherms suitably described the adsorption equilibrium data in the initial metal ion concentration range of 10–50 mg/L. The multicomponent isotherms, including the extended Langmuir and IAST-Freundlich isotherms, were used to predict the binary adsorption of Cd (II) and Zn (II) ions. Furthermore, the appropriate multicomponent isotherm was investigated by minimizing the average relative error (ARE) function. It should be confirmed that the extended Langmuir isotherm fitted the binary adsorption equilibrium data satisfactorily.

Utilization of coal bottom ash as raw material for production of ceramic floor tiles

The aim of this research was to produce ceramic floor tiles using coal bottom ash (CBA), which is a no-value waste from coal power plants, as the raw material. CBA was first mixed with clay at various compositions to determine the proper ratio. Shaping through the dry pressing and single-firing route was chosen for this study. The properties of these ceramic tiles were investigated. Classification of these ceramic tiles has been adopted within the international standard, ISO 13006. Investigation of the optimum conditions for producing this product showed that coal bottom ash content combined with clay in the batch samples should not be more than 40xa0wt% and that the temperature for sintering was 1175xa0°C. The addition of sand could reduce linear shrinkage and increase the whiteness of the fired body. The products had less than 3xa0% water absorption, which is the property in the requirement of group BIb, but flexural strength was in the range of 22–30xa0MPa, which is the property in the requirement of group BIIa. The results obtained indicate that coal bottom ash when mixed with traditional raw materials has potential as a raw material for production of ceramic floor tiles.

Kinetic and mechanism of arsenic ions removal by adsorption on leonardite char as low cost adsorbent material

Adsorption is one of the important techniques in arsenic removal from aqueous solutions. In this study, the As removal efficiency of Leonardite char by a prepared Leonardite carbonized at 450oC was investigated as a function of solution pH, contact time, kinetic and As(III) or As(V) concentration. The surface complexation modeling was used to describe As(III) and As(V) adsorption on the minerals which found in Leonardite char. In the batch experiment, 10.0 mg/L As(III) or As(V) pH 7.0 and 50 mL of aqueous solution was as high as 90% adsorbed. The results showed that Leonardite char could be used as effective adsorbent for the removal of arsenic from aqueous solution. This research supports effort to water with arsenic level lower than 10 mg/L. The maximum adsorption capacity was calculated by fitting the Langmuir and Freunchlich equations to the adsorption isotherms. The Leonardite char will be used as a low-cost adsorbent, for arsenic ions removal in water.

Effect of sodium dodecylbenzene sulfonate on the dispersion stability of ceramic glaze suspension

Sodium dodecylbenzene sulfonate (SDBS) was used to render the stability of ceramic glaze dispersion which is composed of limestone, feldspar, quartz, kaolin and ferric oxide. The measured zeta potential showed negative values for the systems in deionized water and 0.001 M MgCl2 media at pH above 2, but a positive value was observed in 0.1M MgCl2 at pH higher than 6.7. Adsorption of SDBS in aqueous suspensions of ceramic glaze in deionized water and in 0.001 M MgCl2, within the concentration range studied, followed both the Langmuir and Freundlich isotherms, but the Freundlich isotherm was more favored. Adsorption of SDBS in 0.1M MgCl2 corresponded to the Freundlich isotherm. From dispersion stability investigation, SDBS could render the suspension in deionized water and in 0.001 mM MgCl2 more than in 0.1 mM MgCl2.

Utilization of leonardite and coal bottom ash for production of ceramic floor tiles

The aim of this research was to exploit leonardite and coal bottom ash (CBA), which are waste products from coal power plants, for investigating their potential as raw materials in the production of ceramic floor tiles. The developments of ceramic body were mixed with traditional raw materials. Different proportions of ceramic materials were studied in order to explore the proper composition with a variety of wastes containing leonardite and coal bottom ash from 20% up to 80%. Unglazed tiles were produced by shaping through dry pressing and single firing. The physical, chemical, and mechanical properties of the samples were investigated. The total waste (CBA and leonardite) contained in the production was close to 42.8%, and it presented properties that are adequate for it to be classified in groups within the ISO 13006 standard, and yielded the highest flexural strength which enabled the obtained ceramic floor tile bodies to satisfy the requirement to be classified in group BIIa. The chemical resistances of the products were classified in the category UA group which passed the minimum requirement for classification as chemical attack, set by standard EN 14411.

Adsorption isotherm models and error analysis for single and binary adsorption of Cd(II) and Zn(II) using leonardite as adsorbent

AbstractnLeonardite, a by-product from coal mines, was applied to adsorb Cd(II) and Zn(II) from aqueous solutions. Individual and simultaneous adsorptions of the two metal ions were investigated. In a single-component adsorption system, Langmuir and Freundlich isotherms were fitted to the adsorption data. Linear and nonlinear regression methods were used for the assessment of the optimum adsorption isotherm. Error functions including root-mean-square error, sum of the squares of the errors, mean absolute percentage error, Marquardt’s percent standard deviation (MPSD), and Chi-square were applied in the nonlinear regression. The most suitable model for the adsorption of Cd(II) and Zn(II) in the single system is the Freundlich isotherm. The isotherm parameters calculated by MPSD provided the lowest sum of normalized error (SNE) value. The adsorption capacity was found to be 23.89xa0mg/g for Cd(II) and 16.86xa0mg/g for Zn(II). It was observed that the adsorption of Cd(II) on leonardite is greater than that of Zn(II). For binary component adsorption systems, Cd(II) and Zn(II) showed antagonistic behavior. The presence of the other metal ions could decrease the amount of metal adsorbed. Binary adsorption of Cd(II) and Zn(II) was tested with regard to four multi-component isotherms: Extended Langmuir, Modified Langmuir, Sheindorf–Rebuhn–Sheintuch, and Extended Freundlich. The Extended Freundlich isotherm proved to be a good fit for the experimental data.n

Utilization of leonardite, flue gas desulfurization gypsum and clay for production of ceramic plant growth material

The commercial plant growth materials are widely used in a soil-less culture because of their high hardness and ease of use. However, the disadvantages of commercial plant growth materials are expensive because of low density and high pH value. The objective of this research is to produce ceramic plant growth material (CPGM) from leonardite and flue gas desulfurization (FGD) gypsum, which are residues from a coalmine and electric power plant in Lampang province, Thailand, mixed with clay and sawdust. The optimal ratio of these constituents combined with clay was determined, using sawdust residue as an additive. The effect of different quantities of sawdust addition on the properties of CPGM was investigated. The mixtures were formed and fired at 500, 600, 650, 700 and 800xa0°C, respectively. It was found that the weight ratio of 58xa0% leonardite, 17xa0% FGD gypsum and 8xa0% clay with 17xa0% sawdust mixed; firing at 650xa0°C were the most suitable conditions for production of CPGM. The resulting CPGM did not slake when soaked in water having 61.7xa0% water absorption, 75.5xa0% apparent porosity, pH value around 6.4, apparent density of 3.26xa0g/mL, bulk density of 1.39xa0g/mL, CEC value of 19.2xa0meq/100xa0g and surface area of 57.2xa0m2/g. Furthermore, the results from Barrett-Joyner-Halenda analysis showed that the produced CPGM was mesoporous material which has an average pore size of 7.12xa0nm and 89xa0% mesopores.