Papers by Keyword: Bentonite

Abstract: Peat waters were abundant in the West Tanjung Jabung Regency of Jambi Province. Peat water contains manganese metal ion concentration that exceeds the clean water quality standard. Previous studies have been conducted to reduce levels of manganese in peat water, but the results have not been significant. This study aims to reduce levels of Manganese metal in peat water using the composition of Bentonite and Biochar. The adsorption process was carried out at room temperature (29 °C) with a stirring of 200 rpm. Some parameters measured were optimum pH of adsorption, optimum contact time and the best combination between Bentonite and Biochar. Manganese ion concentration in solution was measured using atomic absorption spectroscopy (AAS). The results of this study indicate that the optimum conditions for removing manganese ion at pH 5 and contact time 40 minutes. Tests on artificial solutions using 0.2 grams of biochar showed Mn ion removal of 42.91% (C₀ = 100 mg/L, Ce = 57.09 mg/L, V = 100 mL). The best combination obtained in Bentonite: Biochar (1:2) with a mass of 0.080 gr and 0.170 gr, respectively, which able to remove 91.29% manganese ions in peat water.

Abstract: The paper presents experimental results on the dependence of surface tension on the concentration of a suspension of bentonite (0 - 10% by weight). The isotherms σ of aqueous suspensions of bentonite are characterized by local minima in the concentration range of 3-4 mass% of the solid phase. It has been established that a decrease in the average particle size leads to the disappearance of the extremum on the surface tension isotherms. The data obtained led to the conclusion that the most important factors affecting the nature of the isotherms of the surface tension of bentonite suspensions are the degree of dispersion and the presence in the aqueous suspension of bentonite, both colloidal and coarse particles.

Abstract: Bentonite was modified through intercalation and calcination using a ZrOCl₂ pillaring solution. To create nano Ni/ZrO₂-bentonite catalyst, ZrO₂ pillared bentonite was impregnated using Ni(NO₃)₂•6H₂O precursor first, then followed by calcination and reduction. The physical-chemical properties of the catalyst was characterized by XRD (X-ray Diffractometer), FT-IR (Fourier Transform Infrared), surface acidity with NH₃ vapor adsorption method, SAA (Surface Area Analyzer) and TEM (Transmission Electron Microscope). The results of characterization with XRD showed specific peaks for montmorillonite minerals with a monoclinic crystalline type and its chemical composition (Ca)(Al,Mg)₆(Si₄O₁₀)₃(OH)₆.nH₂O and after pillarization showed a shift in basal spacing d₀₀₁ to the left (angle 2θ <5°). The typical peak indicating basal spacing d₀₀₁ shift towards a smaller angle of 2θ was not very apparent after impregnation with nickel metal. Qualitative determination of acidity after adsorption of ammonia showed characteristics at 1404-1635 cm^-1 wavenumbers with increasingly sharp spectra indicating increased acidity of the catalyst (Brǿnsted and Lewis acids). Surface area showed a significant increase from 27.385 m²/g to 174.208 m²/g after pillarization and impregnation of nickel metal.

Abstract: In this work, soft and flexible poly (ethylene-co-vinyl acetate) (PEVA) with 40% vinyl acetate (VA) composition was used as matrix material to form nanocomposites with single nanofiller (organo-montmorillonite (OMMT) or Bentonite (Bent)) and hybrid nanofillers (OMMT+Bent in the ratios of 4:1, 3:2, 2:3 and 1:4). In order to achieve greater exfoliation and dispersion of the hybrid nanofillers in the PEVA matrix, the pre- dispersing and destabilization technique was applied to the O-MMT and Bent, respectively. The procedures were done prior to the melt compounding process of the nanocomposite. A tensile test was done to evaluate the mechanical properties of the resultant nanocomposites and to allow the selection of the best OMMT/Bent ratio for the production of the hybrid nanocomposite. The structure and fractured surfaces of the neat PEVA and nanocomposite were analyzed using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM), respectively. Results indicated that the addition of hybrid pre-dispersed OMMT/destabilized bentonite nanofillers into the PEVA matrix resulted in greater mechanical performance as compared to the single OMMT or single Bent nanofiller. The best achievement in the tensile strength and elongation at break of the PEVA hybrid nanocomposite was obtained when the hybrid nanofillers was added in the ratio of 4:1 (OMMT: Bent). The SEM analysis showed that the PEVA hybrid nanocomposite with 4OMMT: 1Bent had greater matrix deformation than the neat PEVA when subjected to tensile load. This mechanical deformation could be related to the increased flexibility of the PEVA chains which facilitated more energy absorption during the stretching of the material. Apparently, this mechanism acted as a matrix toughening process which allowed the increment of both tensile strength and elongation at break values of the PEVA upon the addition of the hybrid nanofillers.

Abstract: Soft clayey soils cover wide Iraqi areas specially the regions close to rivers and the southern part of this country Heavy weight structures like: highways, dams, multiple story buildings are suffering unacceptable settlement, when constructing on soft soils. The high contamination of water in such soils decrease the effective stress and reduce bearing capacity. The need was appeared to improve such problematic soil by the use of new technique of stone column treated with different percentages of natural bentonite by a series of field tests using full scale concrete footing constructed on soft soil in addition to a laboratory model to investigate settlement with time at constant stress. The soil that used in this study is natural clayey soil, brought from a location south of Diyala governorate, from a farm area. The study includes also: The effect of stone column diameter treated with bentonite on the behavior of footing constructing on soft clayey soil, The effect of stone column length on the behavior of footing on such soils. Results of field and laboratory model tests reviled that the treated model by stone column mixed with 40% bentonite is the ideal one, which reduces the settlement by 55%. In other hand problems of uneven settlements appear when using 60% bentonite as a mix proportion. The Ideal slenderness ratio (Ds/Ls<25%). The effective depth of stone column treated with bentonite is (1/3H).

Abstract: Cracking, shrinkage, and curling of soils, in general, take place due to drying. These deformations lead to many problems include the development of main paths for water flow and pollutant transport, reduction of soil strength (and impact on other mechanical properties of soils), erosion in slopes, landslides, increase infiltration capacity of the soil and the differential settlement problems. Few studies have investigated the effect of wetting-drying (W-D) cycles on desiccation cracks of soils. The effect of multiple wetting-drying cycles in the cracking behavior was investigated in this research by performing several wetting-drying (W-D) cycles on the initially saturated samples (of pure kaolinite and a mixture of kaolinite with bentonite) under the lab atmosphere (24 ± 1 °C, and 52 ± 2% of RH). The weight of each sample was monitored using a computerized scale (with an accuracy of 0.01 g) connected to the computer. During the test, the water evaporation path with the development of surface cracks and volume shrinkage was monitored by means of digital images. It was observed that the crack patterns changed during the initial cycles, but there was an equilibrium state in the third and fourth W-D cycles. Additionally, it was observed that the main cracks formed in the first dry path were virtually closed after 10 minutes of the second wetting path; in the meantime, small cracks (fissures) were initiated after this wetting process. It was, also, detected that soils with high plasticity required more W-D cycles to reach the equilibrium condition than soils with low plasticity. The results of these experiments are useful for understanding the effect of different seasons on soil behavior.

Abstract: The paper will use BP neural network analysis method to study the thermal conductivity of bentonite and its influencing factors as a system. The heat conduction of bentonite was used as the output of the system, and its influencing factors were used as the system input to simulate. The corresponding simulation model was established to verify the thermal conductivity data. In addition, the analysis of the mechanical properties of the bentonite-PVA fiber cement-based composite materials for construction has not only laid a theoretical and realistic foundation for the prediction and simulation of the thermal conductivity of bentonite, but also has opened up the mechanical properties of the bentonite-PVA fiber cement-based composite materials a new path.

Abstract: Polystyrene is a type of plastic that is widely used in daily life. It is applied for decoration, food packaging, and electronic packaging process. However, the use of polystyrene has become a problem for the environments because its properties are difficult to be degraded by nature. Pyrolysis method can be regarded as one of the environmentally friendly methods for recycling polystyrene waste. This research aims to investigate the effect of bentonite and natural zeolite catalyst on the pyrolysis of polystyrene. The experiment was carried out in a batch process. The pyrolysis process consists of a cylindrical reactor with electrical heater, a condenser, and a liquid product container. About 100 grams of polystyrene material was pyrolysis per batch. Catalysts used in the variation of 0%, 10%, 15%, 20%, and 25% of polystyrene. The liquid product was collected in 60 minutes and weighed. The composition of the liquid product was determined by gas chromatography. Polystyrene pyrolysis utilizes bentonite and natural zeolite as the catalyst. It produces benzene, toluene, ethylbenzene, styrene, and isopropyl benzene as the liquid product, and polystyrene residue as a solid product. Among the catalyst studied, bentonite is found to be the most efficient and increase the styrene selectivity (30.28 wt%) significantly at a reaction temperature of 400°C in comparison to the natural zeolite catalyst.

Abstract: Zeolite X were successfully synthesized from bentonite from Lopburi province, in Thailand using the two-step of hydrothermal method under optimum condition without calcination. The first step of hydrothermal were obtained at 200 °C for 3 h to remove unreacted impurity minerals such as quartz and muscovite. The secondary step of hydrothermal were obtained at 90 °C for 120 h for synthesis of zeolite X. The characterization of zeolite X were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), and infrared spectroscopy (FT-IR), respectively. The crystal structure of product was determined as zeolite X by XRD. The morphology of SEM images for zeolite X is octahedral shape. FTIR spectra are in accordance with the other characterization results.

Abstract: Research on the adsorption of Cd (II) ion in dithizone-immobilized natural bentonite has been carried out. The aims of this research were focused on the preparation of dithizone-immobilized natural bentonite (BA-D) as adsorbent and desorption experiment of Cd(II) ion. The BA-D was prepared by adding dithizone (dissolved in toluene) into the activated natural bentonite. The adsorbents were characterized by FTIR and X-Ray Diffraction (XRD). This research showed that adsorption capacities of BA-A and BA-D were 1.70×10^‒5 and 2.77×10^‒5 mol g^‒1 (46% of increasing). According to desorption experiment, interaction between activated natural bentonite and Cd(II) ionwere performed by electrostatic interaction, formation of hydrogen bond and complex formation.