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Adsorption and photocatalytic degradation behaviours of cationic dye BV16 in ZnO-Ghezeljeh nanoclay composite/UV-C system: Equilibrium, kinetic and thermodynamic studies

2019-01-01T11:12:43Z

Title: Adsorption and photocatalytic degradation behaviours of cationic dye BV16 in ZnO-Ghezeljeh nanoclay composite/UV-C system: Equilibrium, kinetic and thermodynamic studies Authors: Siahpoosh, Zahra Hassanzadeh; Soleimani, Majid Abstract: Ghezeljeh montmorillonite nanoclay or “Geleh-Sar-Shoor” (means head-washing clay) has been used as a natural adsorbent to photocatalytic decolorization of BV16 dye under UV radiation. The results of XRD, FT-IR, CEC, Specific surface area and Zeta potential of the Ghezeljeh clay confirm that montmorillonite is the dominant mineral phase. Based on SEM images, it can be understood that the distance between the plates is in nm level. Adsorption of BV16 on to different clays might inhibit its photodegradation has been investigated. The photocatalytic decolorization of BV16 dye under UV radiation in aqueous ZnO-natural Ghezeljeh nanoclay composite suspension compared to the behavior of the dye on Ghezeljeh nanoclay, ZnO-Ghezeljeh nanoclay (shell-core), Cloisite Na⁺nanoclay, ZnO-Cloisite Na⁺nanoclay composite, ZnO-Cloisite Na⁺nanoclay (shell-core). The linearity of the plots (R²) demonstrates that pseudo-second order kinetic model play a significant role in the uptake of the dye. The R² values show that the dye removal isotherm using ZnO-natural Ghezeljeh nanoclay composite follows the Langmuir isotherm at natural temperature and Dubinin–Radushkevich isotherm at upper temperature. Calculation of ΔG⁰, ΔH⁰ and ΔS⁰ showed that the procedure is feasible, spontaneous and endothermic. Page(s): 505-521

Adsorptive desulfurization and denitrogenation by nickel impregnated activated carbon

2019-01-01T09:52:36Z

Title: Adsorptive desulfurization and denitrogenation by nickel impregnated activated carbon Authors: Thaligari, Sandeep Kumar; Gupta, Shelaka; Srivastava, Vimal Chandra; Prasad, Basheshwer Abstract: Nickel impregnated granular activated carbon (Ni-GAC) has been synthesized and characterized by various techniques like BET, FTIR, SEM, EDX and TGA. It is later employed for the individual adsorption of dibenzothiophene (DBT) and quinoline (QN). The influence of various factors such as percentage of Ni loading, initial concentration, time, adsorbent dose and temperature on the individual adsorption of DBT and QN from model fuel by Ni-GAC have been investigated. On the basis of the present study, 1%Ni-GAC is found to be the best among various wt.% Ni-GAC. Equilibrium time for DBT and QN adsorption is found to be 6 hr and 9 hr, respectively. The optimum adsorbent dose is found to be 20 g/L. Adsorption kinetics of the both DBT and QN are represented by pseudo-second-order kinetic model. For single component systems, the experimental equilibrium data is well matched with R-P isotherm. Values of change in enthalpy and entropy for DBT and QN were found to be 2.04, 1.55 kJ/mol and 10 and 20 J/mol K, respectively. Isosteric heat of adsorption is modeled in terms of surface heterogeneity. Page(s): 522-530

Study on the adsorption characteristics of aqueous caffeine solutions on macroporous resins with hydrogen-bonding interactions

2019-01-01T09:50:11Z

Title: Study on the adsorption characteristics of aqueous caffeine solutions on macroporous resins with hydrogen-bonding interactions Authors: Zhao, Qingsheng; Yin, Jinhua; Wang, Xu; Du, Deqing; Ye, Qingguo Abstract: The adsorption characteristics of caffeine on six macroporous resins have been investigated. The results show that the resin with hydroxyl groups (XDA-200) offer better adsorption/ desorption capacity than other resins, and its adsorption kinetics fit a pseudo- second-order model. The adsorption process is a type of fast adsorption, and multiple adsorption mechanisms controlled the rate of adsorption. The isothermal equilibrium curve of caffeine adsorbed onto XDA-200 show a good fit to the Freundlich model, and thermodynamics tests show that the process is exothermic and spontaneous. The absolute value of enthalpy is 14.347 kJ/mol, which is in the range of the adsorption enthalpy related to hydrogen-bonding interactions. XPS and FTIR analyses also verify the existence of hydrogen-bonding interactions. Page(s): 531-538

Synthesis of a novel polyetheramide-polyaniline composite anticorrosive coating from PET waste and jatropha oil

2019-01-01T09:47:24Z

Title: Synthesis of a novel polyetheramide-polyaniline composite anticorrosive coating from PET waste and jatropha oil Authors: Rane, Pradnya C; More, Aarti P; Mhaske, Shashank T Abstract: Polyethylene Terephthalate (PET) has been depolymerized by aminolysistechnique using ethanolamine to bis(2-hydroxyethyl) terephthalamide (BHETA). BHETA is a diol along with additional amide linkage as a structural part. It is used as hydroxyl precursor for the synthesis of polyetheramide resin. The conventional polyetheramide resin has been prepared by jatropha oil fatty acid amide and resorcinol. The modification is done in conventional resin with addition of BHETA by replacing fatty amide of oil on 50:50 molar basis. The synthesized resin was characterized by FTIR, ¹HNMR and hydroxyl value. The synthesized resins are cured with Melamine Formaldehyde (MF) resin as a hardener and coating is prepared. The coating is evaluated for chemical, mechanical and anticorrosive properties. The anticorrosive performance of BHETA based polyetheramide is further improved by addition of polyaniline at various concentrations in coating system. 3wt% addition of polyaniline in BHETA based polyetheramide resin was shows best anticorrosive properties among all studied formulations. Page(s): 539-545