Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5

freundlich Related Abstracts

5 Magnetic Activated Carbon: Preparation, Characterization, and Application for Vanadium Removal

Authors: Mansooreh Soleimani, Hakimeh Sharififard


In this work, the magnetic activated carbon nanocomposite (Fe-CAC) has been synthesized by anchorage iron hydr(oxide) nanoparticles onto commercial activated carbon (CAC) surface and characterized using BET, XRF, SEM techniques. The influence of various removal parameters such as pH, contact time and initial concentration of vanadium on vanadium removal was evaluated using CAC and Fe-CAC in batch method. The sorption isotherms were studied using Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. These equilibrium data were well described by the Freundlich model. Results showed that CAC had the vanadium adsorption capacity of 37.87 mg/g, while the Fe-AC was able to adsorb 119.01 mg/g of vanadium. Kinetic data was found to confirm pseudo-second-order kinetic model for both adsorbents.

Keywords: nanocomposite, vanadium, magnetic activated carbon, remove, freundlich

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4 Cobalt Ions Adsorption by Quartz and Illite and Calcite from Waste Water

Authors: Saad A. Aljlil


Adsorption of cobalt ions on quartz and illite and calcite from waste water was investigated. The effect of pH on the adsorption of cobalt ions was studied. The maximum capacities of cobalt ions of the three adsorbents increase with increasing cobalt solution temperature. The maximum capacities were (4.66) mg/g for quartz, (3.94) mg/g for illite, and (3.44) mg/g for calcite. The enthalpy, Gibbs free energy, and entropy for adsorption of cobalt ions on the three adsorbents were calculated. It was found that the adsorption process of the cobalt ions of the adsorbent was an endothermic process. consequently increasing the temperature causes the increase of the cobalt ions adsorption of the adsorbents. Therefore, the adsorption process is preferred at high temperature levels. The equilibrium adsorption data were correlated using Langmuir model, Freundlich model. The experimental data of cobalt ions of the adsorbents correlated well with Freundlich model.

Keywords: Adsorption, Waste water, quartz, langmuir, freundlich, illite, calcite

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3 Functionalized Mesoporous Silica: Absorbents for Water Purification

Authors: Muhammad Aqeel Ashraf, Uzaira Rafique, Saima Nasreen, Shery Ehrman


The release of heavy metals into the environment is a potential threat to water and soil quality as well as to plant, animal and human health. In current research work, organically functionalized mesoporous silicates (MSU-H) were prepared by the co-condensation between sodium silicate and oregano alkoxysilanes in the presence of the nonionic surfactant triblock copolymer P104. The surfactant was used as a template for improving the porosity of the hybrid gels. Synthesized materials were characterized by TEM, FT-IR, SEM/EDX, TG, surface area analysis. The surface morphology and textural properties of such materials varied with various kinds of groups in the channels. In this study, removal of some heavy metals ions from aqueous solution by adsorption process was investigated. Batch adsorption studies show that the adsorption capacity of metal ions on the functionalized silicates is more than that on pure MSU-H. Data shows adsorption on synthesized materials is a time efficient process, suggesting adsorption on external surface as well as the mesoporous process. Adsorption models of Langmuir, Freundlich, and Temkin depicted equal goodness for all adsorbents, whereas pseudo 2nd order kinetics is in best agreement with experimental data.

Keywords: Hybrid, Heavy Metals, Adsorption, mesoporous silica, langmuir, freundlich, temkin

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2 Removal of Pb²⁺ from Waste Water Using Nano Silica Spheres Synthesized on CaCO₃ as a Template: Equilibrium and Thermodynamic Studies

Authors: Joseph Govha, Milton Manyangadze, T. Bala Narsaiah, Ch. Shilpa Chakra


The availability and access to fresh water is today a serious global challenge. This has been a direct result of factors such as the current rapid industrialization and industrial growth, persistent droughts in some parts of the world, especially in the sub-Saharan Africa as well as population growth. Growth of the chemical processing industry has also seen an increase in the levels of pollutants in our water bodies which include heavy metals among others. Heavy metals are known to be dangerous to both human and aquatic life. As such, they have been linked to several diseases. This is mainly because they are highly toxic. They are also known to be bio accumulative and non-biodegradable. Lead for example, has been linked to a number of health problems which include damage of vital internal body systems like the nervous and reproductive system as well as the kidneys. From this background therefore, the removal of the toxic heavy metal, Pb2+ from waste water was investigated using nano silica hollow spheres (NSHS) as the adsorbent. Synthesis of NSHS was done using a three-stage process in which CaCO3 nanoparticles were initially prepared as a template. This was followed by treatment of the formed oxide particles with NaSiO3 to give a nanocomposite. Finally, the template was destroyed using 2.0M HCl to give NSHS. Characterization of the nanoparticles was done using analytical techniques like XRD, SEM, and TGA. For the adsorption process, both thermodynamic and equilibrium studies were carried out. Thermodynamic studies were carried out and the Gibbs free energy, Enthalpy and Entropy of the adsorption process were determined. The results revealed that the adsorption process was both endothermic and spontaneous. Equilibrium studies were also carried out in which the Langmuir and Freundlich isotherms were tested. The results showed that the Langmuir model best described the adsorption equilibrium.

Keywords: Characterization, Nanoparticles, langmuir, freundlich, endothermic, equilibrium studies, thermodynamic studies

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1 Application of Synthetic Monomers Grafted Xanthan Gum for Rhodamine B Removal in Aqueous Solution

Authors: Tshepiso Moremedi, Lebogang Katata-Seru, Soumen Sardar, Abhijit Bandyopadhyay, Edwin Makhado, Mpitloane Joseph Hato


The rapid industrialisation and population growth have led to a steady fall in freshwater supplies worldwide. As a result, water systems are affected by modern methods upon use due to secondary contamination. The application of novel adsorbents derived from natural polymer holds a great promise in addressing challenges in water treatment. In this study, the UV irradiation technique was used to prepare acrylamide (AAm) monomer and acrylic acid (AAc) monomer grafted xanthan gum (XG) copolymer. Additionally, various factors affecting rhodamine B (RhB) adsorption from an aqueous medium such as pH, adsorbent dose, initial dye concentration, solution temperature and contact time were investigated. The FTIR results confirmed the formation of graft copolymer between AAm and AAc. The SEM showed some irregular, porous and wrinkled surface morphology of XG-g-pAAm-co-AAc indicating successful copolymerization of the reacting monomers. The optimum conditions for removing RhB dye with a maximum adsorption capacity of 313 mg/g at 25 oC and pH 5 was obtained. The adsorption of RhB followed Freundlich’s model in all cases. Kinetic studies indicated that the pseudo-second-order model can be employed for describing the dynamics of the adsorption process. Therefore, grafted XG has tremendous potential to be used as an adsorbent to remove cationic dyes from aqueous solutions.

Keywords: adsorbents, rhodamine B, freundlich, xanthan gum

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