Adsorption of Hg2+ and Ni2+ from Aqueous Solutions Using Unmodified and Carboxymethylated Granular Activated Carbon (GAC)
Francis Kalu Onwu,
Christopher Uchechukwu Sonde,
Jude Chibuzo Igwe
Issue:
Volume 3, Issue 6, December 2014
Pages:
89-95
Received:
22 October 2014
Accepted:
29 October 2014
Published:
2 December 2014
Abstract: The use of unmodified and carboxymethylated granular activated carbon (GAC) for adsorption of Hg2+ and Ni2+ from aqueous solutions was assessed in this work. The effect of concentration and modification by carboxymethyl group on the adsorption of these metal ions was studied in batch process. The adsorption data were correlated with Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models. Results show that Freundlich model gave the best description for the adsorption process followed by the Langmuir model. Langmuir adsorption capacity corresponding to sites saturation was found to be 20.83 mg g-1 and 19.05 mg g-1 for adsorption of the Hg2+ and Ni2+ respectively onto the unmodified adsorbent and 19.72 mg g-1 and 17.01 mg g-1 for adsorption onto the carboxymethylated substrate. The apparent energy values obtained from the Dubinin-Radushvich model further indicates that the forces of the adsorption follow physical mode. Modification by carboxymethyl group generally caused a decline in the adsorption capacity by the adsorbent. Results obtained generally showed that Hg (II) ions were better adsorbed onto both adsorbents as compared to Nickel (II).
Abstract: The use of unmodified and carboxymethylated granular activated carbon (GAC) for adsorption of Hg2+ and Ni2+ from aqueous solutions was assessed in this work. The effect of concentration and modification by carboxymethyl group on the adsorption of these metal ions was studied in batch process. The adsorption data were correlated with Langmuir, Freun...
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Physicochemical and Mineralogical Characterization of Moroccan Bentonite of Trebia and Its Use in Ceramic Technology
Azzeddine Er-ramly,
Abdelali Ider
Issue:
Volume 3, Issue 6, December 2014
Pages:
96-101
Received:
11 June 2014
Accepted:
4 July 2014
Published:
16 December 2014
Abstract: This study concerns the results of Physicochemical and mineralogical characterization of a white bentonite of Trebia located in Nador region in Morocco and its use in the ceramics industry. Several techniques were used; in particular X-ray diffraction (XRD), scanning electron microscopy coupled with EDX microanalysis (SEM-EDX), differential thermal and gravimetric analyses (DTA-TGA) and finally infrared Fourier transform (FTIR) and X-ray fluorescence (XRF). The first objective of this work is to look for the usability of bentonite of Trebia in ceramic technology. The second objective was to develop gels of oxides of high purity from these clays. We can say that the white bentonite of Trebia has the same characteristics of clays used in the ceramics industry (medium heat loss, low shrinkage, good flexural strength and good behavior in plasticity), this white bentonite of Trebia adding 0,42% sodium carbonate is sufficient to have a good deflocculation and the viscosity is minimum corresponds to the stability of the slip, in his introduction to a formula of slip was successful with a rate of 10 to 14%. The SEM-EDX, X-ray, chemical analysis and Infrared spectroscopy demonstrated and allowed us to identify the different minerals that make up the white clay, compared with the available data, we identified Montmorillonite, feldspath and quartz as bentonite of Trebia, other minerals present as impurities major are magnetit and iron oxide. These results show the important features to justify its use in the ceramic industry.
Abstract: This study concerns the results of Physicochemical and mineralogical characterization of a white bentonite of Trebia located in Nador region in Morocco and its use in the ceramics industry. Several techniques were used; in particular X-ray diffraction (XRD), scanning electron microscopy coupled with EDX microanalysis (SEM-EDX), differential thermal...
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A Novel Visible– Light Driven Photocatalyst: Ethylene Glycol–Citrate Sol–Gel Synthesis, Microwave–Assisted Calcination, and Photocatalytic Efficiency
Hakim Qaid Naji Museed Alarique,
Elyas Sadeq Al-Aghbari,
Niyazi Abdulmawla Sallam Al–Areqi,
Ahlam Al–Alas,
Khalid Ahmed Saeed Ghaleb
Issue:
Volume 3, Issue 6, December 2014
Pages:
102-108
Received:
29 November 2014
Accepted:
7 December 2014
Published:
18 December 2014
Abstract: A novel visible– light driven photocatalyst, BIMNVOX.x was synthesized by ethylene glycol–citrate sol–gel route and microwave- assisted calcination. The phocatalyst was characterized structurally by X–ray powder diffraction (XRPD) and simultaneous thermogravimetric–differential thermal analysis (TG–DTA). Its optical and surface properties were determined by means of UV–vis absorption spectrophotometry and BET– nitrogen adsorption isotherm measurements, respectively. The photocatalytic efficiency of BIMNVOX.x system was investigated by applying the pseudo first- order kinetic model to the photocatalytic degradation reaction of crystal violet, CV dye in aqueous solution under visible light irradiation. The β (orthorhombic) –BIMNVOX phase, space group Acam exhibited the highest photocatalytic degradability, indicating that the photocatalytic efficiency of BIMNVOX catalyst is essentially enhanced by the increased number of catalyst active sites, irrespective of the kind of phase stabilized and the increasing photoabsorption ability with Mn dopant content. Moreover, the possible photocatalytic degradation mechanism of aqueous CV dye solution under visible light irradiation was also proposed.
Abstract: A novel visible– light driven photocatalyst, BIMNVOX.x was synthesized by ethylene glycol–citrate sol–gel route and microwave- assisted calcination. The phocatalyst was characterized structurally by X–ray powder diffraction (XRPD) and simultaneous thermogravimetric–differential thermal analysis (TG–DTA). Its optical and surface properties were dete...
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