The role of metacognitive listening strategies awareness and podcast-use readiness in using podcasting for learning English as a foreign language

The aim of this study was to investigate the role of English as Foreign Language (EFL) learners’ metacognitive listening strategies awareness and podcast-use readiness in using podcasting technology for learning English as a foreign language. One hundred and forty-one EFL students completed Metacognitive Awareness Listening Questionnaire (MALQ) that assessed their awareness and perceived use of listening strategies in five components including planning-evaluation, directed attention, person knowledge, mental translation, and problem solving. They also completed a questionnaire that assessed their readiness to use podcasting in terms of familiarity, attitude, and experience. Information on participants’ frequency of podcast use for learning English, frequency of the internet use, and digital device ownership was also obtained. The result of the analysis revealed that podcasting use was significantly related to metacognitive listening strategies awareness in general and its entire components except mental translation strategies while the strongest correlation was found with problem solving strategies (r = .49, p < 0.01). Podcasting use was also found to be significantly related to perceived podcast-use readiness and internet use hours. Further, multiple regressions showed that perceived podcast-use readiness, problem solving, and person knowledge -in order of power prediction- were good predictors of podcasting use for learning English as a foreign language.     

Study effect of different parameters on the sulphate sorption onto nano alumina

The aim of this research work is to investigate sorption characteristic of modified nano alumina (n-Al) for the removal of SO₄^2? from aqueous solutions and wastewater. The sorption of SO₄^2? by batch method is carried out. The optimum conditions of sorption were found to be: a sorbent dose of 0.3 g in 100 ml of SO₄^2?, contact time of 35 min, pH = 5. In optimum condition, removal efficiency was 85.6% for the SO₄^2?. Three equations, i.e. Morris–Weber, Lagergren and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich and D–R are subjected to sorption data to estimate sorption capacity. It can be concluded that n-Al has potential to remove SO₄^2? ions from aqueous solutions at different concentrations. It was found that the temperature has positive effect on the process and negative ΔG values indicated thermodynamically feasible and spontaneous nature of the sorption. Positive value of ΔS reveals the increased randomness at the solid–solution interface during the fixation of the ion on the active sites of the sorbent. The effect of other anions was studied and it was found the existence of them in the solution has considerable effect on the sulphate removal.     

Application of nanometer size of polypyrrole as a suitable adsorbent for removal of Cr(VI)

The objective of this work was to investigate the sorption characteristics of polypyrrole (PPy) for the removal of Cr(VI) from aqueous solutions. The sorption process was carried out by a dynamic batch method in order to determine the optimum conditions. For a sorbent dose of 0.6 g in 100 mL of a Cr(VI) solution, at a contact time of 15 min and a pH of 3, a removal efficiency of 84.5% was achieved. The Morris–Weber and Lagergren equations, as well as a pseudo‐second‐order equation were examined to explore the kinetics of the removal process. In addition, the Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were applied to estimate the capacity, intensity, and energy of the sorption process. It was found that increasing temperature showed a positive effect on the ion sorption efficiency. In summary, PPy was shown to be a suitable candidate for chromium(VI) ion removal from aqueous solutions at different concentrations. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers.     

Zn(II) ion removal from aqueous solution by using a polyaniline composite

The aim of this research was to investigate the sorption characteristics of polyaniline/sawdust (PAn/SD) for the removal of Zn(II) ions from aqueous solutions. Batch sorption studies were carried out to determine the effect of initial concentration of the sorbate, agitation time, adsorbent dose, and pH on the removal of Zn(II). The sorptive removal was found to be strongly pH‐dependent. The experimental data fitted well to the Freundlich isotherm. The products were investigated in terms of morphology and chemical structure by using scanning electron microscopy and Fourier‐transform infrared spectroscopy, respectively. Also, PAn/SD was used for the removal of heavy metals from urban waste water. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers     

Removal of oil from biodiesel wastewater by electrocoagulation method

An attempt has been made to remove oil and grease (O&G) from biodiesel wastewater as well as O&G and turbidity in the presence of H₂O₂ and polyaluminum chloride (PAC), as a coagulant-aid by an electrochemical method using iron as sacrificial electrodes. The effects of current density, amount of hydrogen peroxide using as an oxidizing agent and addition of coagulant-aid, on percent removal and energy consumption have been investigated. The removal efficiency of O&G was in the range of 62–86%, whereas O&G removal was 100% in the current density range of 10–12.5 mAcm^?2 depending on the concentrations of H₂O₂ and coagulant aid. It is obtained that electrocoagulation in the absence of coagulant aid and oxidant is not too efficient for the treatment of this type of wastewater.     

Kinetic,isotherm and thermodynamic study of nitrate adsorption from aqueous solution using modified rice husk

In this article, we prepared anionic sorbent using rice husk (RC). Anionic rice husk (ARC) structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The sorption of NO₃^? by batch method is carried out. The optimum conditions of sorption were found to be: a sorbent dose of 0.4 g in 100 mL of NO₃^? solution, contact time of 90 min, pH = 7. In optimum condition, removal efficiency was 94.3% for the NO₃^?. The nitrate adsorption process was well described by the pseudo-second-order kinetic model, and the experimental isotherm data fitted well with the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. Thermodynamic parameters such as Gibbs free energy change, enthalpy change and entropy change were calculated and the results showed that the adsorption of nitrate on ARC was spontaneous and exothermic in nature. The effect of other anions were also studied and was found that the anions reduced the nitrate adsorption in the order of carbonate > chloride > phosphate > sulphate. ARC was used for the removal of NO₃^? from real wastewater (urban wastewater) that high performance of adsorbent was considerable.     

Artificial neural network (ANN) approach for modeling of Cr(VI) adsorption from aqueous solution by zeolite prepared from raw fly ash (ZFA)

In this present work, artificial neural networks (ANN) are applied for prediction of percentage adsorption efficiency for the removal of Cr(VI) ions from aqueous solution by zeolite (ZFA) prepared from raw fly ash (RFA). The off operational parameters such as initial pH, adsorbent dosage, contact time and temperature is studied to optimize the conditions for maximum removal of Cr(VI) ions. Three equations, i.e. Morris–Weber, Lagergren, and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich, Redlich–Peterson, Temkin, and D-R are subjected to sorption data to estimate sorption capacity. Thermodynamic parameters showed that the adsorption of Cr(VI) onto ZFA was feasible, spontaneous and endothermic. Artificial neural networks are effective in modeling and simulation of highly non-liner multivariable relationships. The comparison of the removal efficiencies of Cr(VI) using ANN model and experimental results showed that ANN model can estimate the behavior of the Cr(VI) removal process under different conditions.     

Fixed‐bed column study of the removal of anions and heavy metals from cotton textile waste water by using polyaniline and its nanocomposite containing nanometer‐size Fe3O4

Preparation of polyaniline (PAn) and its nanocomposite containing nanometer‐size Fe₃O₄ is discussed, and their capability of separating anions and heavy metals from cotton textile industry waste water is studied. The removal of anions and heavy metals from the waste water was investigated and compared when PAn, nanometer‐size Fe₃O₄, and PAn/Fe₃O₄ nanocomposite were used. The results indicated that PAn and its composite were able to remove the anions and heavy metals. The anion and heavy metal removal percentages were increased by using PAn and nanometer‐size Fe₃O₄. The morphology and chemical structure of the adsorbents were investigated by scanning electron microscopy and Fourier transform infrared spectroscopy. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

Synthesis of Fe3O4/polyaniline nanocomposite and its application for nitrate removal from aqueous solutions

The aim of this work was to investigate the sorption characteristics of Fe₃O₄ coated on polyaniline (Fe₃O₄/PAn) for the removal of NO₃^? ions from aqueous solutions. The sorption of NO₃^? ions by the batch method was carried out. The optimum conditions of sorption were found to be a Fe₃O₄/PAn dose of 0.4 g in 100 mL of NO₃^? solution, a contact time of 10 min, pH and temperature 7 and 40°C, respectively. Temperature had a negative effect on the removal efficiency. Three equations, i.e., Morris–Weber, Lagergren, and pseudo‐second‐order, were tested to track the kinetics of the removal process. The Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were subjected to sorption data in order to estimate sorption capacity, intensity, and energy. The thermodynamic parameters ΔH, ΔS, and ΔG were evaluated. They showed that the adsorption of NO₃^? onto Fe₃O₄/PAn was feasible, spontaneous, and exothermic under the studied conditions. It can be concluded that Fe₃O₄/PAn has potential to remove NO₃^? ions from aqueous solutions at different concentrations. The system Fe₃O₄/Pan was successfully tested for a high removal efficiency of NO₃^? from urban wastewater. J. VINYL ADDIT. TECHNOL., 19:147–156, 2013. © 2013 Society of Plastics Engineers     

Synthesis of polyaniline nanocomposite and its application for chromium removal from aqueous solution

The aim of this research was to investigate the sorption characteristics of polyaniline coated on sawdust (PAn/SD) for the removal of Cr(VI) ions from aqueous solutions. The sorption of Cr(VI) ions was carried out by the batch method. Characterization of PAn/SD was done by FTIR and SEM. The optimum conditions of sorption were found to be a PAn/SD dose of 0.6 g in 100 mL of Cr(VI) solution (50 mg/L), a contact time of 20 min, pH 2, and a temperature of 20°C, Increased temperature had a negative effect on the removal efficiency. Three equations, that is Morris–Weber, Lagergren, and pseudo‐second‐order, were tested to track the kinetics of the removal process. The kinetic data indicated that the adsorption process was described by the Morris–Weber equation. The Langmuir, Freundlich, and Dubinin–Radushkevick models were used with sorption data to estimate sorption capacity, intensity, and energy. The data were fitted with the Freundlich model. The thermodynamic parameters ΔH, ΔS, and ΔG were evaluated. They showed that the adsorption of Cr(VI) onto PAn/SD was feasible, spontaneous, and exothermic under the studied conditions. For desorption of Cr(VI) adsorbed onto PAn/SD, aqueous NaOH was used; with it, 85% of the adsorbed Cr(VI) could be desorbed. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers