VOLUME 34, NO6, DEC 2012

A Review on Technologies for Oil Shale Surface Ret

In recent years, with the shortage of oil resources and the continuous increase in oil prices, oil shale has seized much more attention. Oil shale is a kind of important unconventional oil and gas resources. Oil shale resources are plentiful according to the proven reserves in places. And shale oil is far richer than crude oil in the world. Technology processing can be divided into two categories: surface retorting and in-situ technology. The process and equipment of surface retorting are more mature, and are still up to now, the main way to produce shale oil from oil shale. According to the variations of the particle size, the surface retorting technologies of oil shale can be notified and classified into two categories such as lump shale process and particulate shale process. The lump shale processes introduced in this article include the Fushun retorting technology, the Kiviter technology and the Petrosix technology; the particulate processes include the Gloter technology, the LR technology, the Tosco-II technology, the ATP (Alberta Taciuk Process) technology and the Enefit-280 technology. After the thorough comparison of these technologies, we can notice that, this article aim is to show off that : the particulate process that is environmentally friendly, with its low cost and high economic returns characteristics, will be the major development trend; Combined technologies of surface retorting technology and other oil producing technology should be developed; the comprehensive utilization of oil shale should be considered during the development of surface retorting technology, meanwhile the process should be harmless to the environment.read more

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YI PAN, XIAOMING ZHANG, SHOUHUI LIU, SHUANGCHUN YANG AND NAN REN

Electrochemical Behavior of 1, 4-Butanediol at Nic

The composite film comprising nickel oxide dispersed in polyaniline was used to investigate the electro-oxidation of 1,4-butanediol in alkaline media. The composite film was electrochemically deposited using nickel sulphate and aniline solution. Surface coverage of the film in alkaline medium at different scan rates was indicated to involve a few hundred monolayers. Chronoamperometric and chronopotentiometric responses indicated that electro-oxidation of 1, 4-butanediol initiates from the very start of the anodic scan.read more

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INAM-UL-HAQUE, AIKIFA RAZA, GULZAR FATIMA AND MUQADDAS TARIQ

Anodic Coupling of Aniline

Electrochemical behavior of aniline at platinum electrode was studied in acetonitrile. The results are compared with those of carbon paste electrode. Our results show little variation from the carbon paste electrode when the picric acid / picrate are present in the setup while without picric acid / picrate our results are comparable to that of the carbon paste electrode. Mechanism can be diagnosed from number of possibilities by taking the consideration of the slopes -dEp / dlogC and dEp / dlog and dEp / dlogX by comparing the theoretical and experimental values. Results are also compared with the slopes obtained in distilled water and in 9:1 acetonitrile /water, shows great variation.read more

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INAM-UL-HAQUE AND SHAMAILA SADAF

Flotation–Spectrophotometric Method for Separation

A flotation–spectrophotometric method for the determination of Cu2+ has been developed. The flotation process is based on the formation of a ternary ion-associate between Cu2+, methylthymol blue (MTB) and cetyltrimethylammonium bromide (CTAB) which is floated at the interface of aqueous phase and n–hexane by shaking in a separating funnel. The aqueous solution is discarded and the adsorbed ion associate (Cu2+–MTB–CTA+) on to the wall of a separating funnel is dissolved in a small volume of methanol solvent and its absorbance is measured at 556 nm. The apparent molar absorptivity (ε) of the ion associate was determined to be 6.1×104 L mol-1 cm-1. The calibration curve was linear in the concentration range of 10-400 ng mL-1 of Cu2+ with a correlation coefficient of 0.9994. The limit of detection (LOD) was 6.7 ng mL-1. The relative standard deviation (RSD) for 50 and 300 ng mL-1 of Cu2+ was 3.9% and 1.3% (n=7), respectively. The method was successfully applied to the determination of Cu in water samples from water treatment process of Ramin power plant, Iran.read more

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NAHID POURREZA, HOOSHANG PARHAM AND PARVIN MIRZAVAND

Biosorption of Copper (II) on Dry Fruit by Product

Biosorption of copper (II) using walnut shell powder (WNSP) appeared to be an efficient and effective decontamination method. XRD revealed the amorphous nature of the biosorbent and absence of metallic phase in it while FT – IR spectra indicated the surface heterogeneity in terms of functional groups. Removal of copper (II) by walnut shell powder followed a fast kinetic at 30 ̊C ± 2 ̊C. Three typical kinetic models namely elovich, pseudo first and second order equations were analyzed to interpret the kinetic data. Pseudo second order kinetic enumerated the biosorption of copper (II) onto walnut shell powder best. Adsorption isothermal data was examined by classical two parameters (Langmuir, Freundlich, Dubinin-Radushkevic) and three parameters (Redlich-Peterson and Toth) models. With the aid of these models various aspects of copper (II) biosorption onto walnut shell powder were explored. Coefficient of determination (R2) was used as the criteria of best fit for a model. Based on R2 among two parameters models Langmuir isotherm enumerated the experimental data best and among three parameters models Redlich-Peterson isotherm gave the best description of the work conducted.read more

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MOHSIN KAZMI, NADEEM FEROZE, HASSAN JAVED, MUHAMMAD ZAFAR AND NAVEED RAMZAN

Effect of UVC Irradiation on Aflatoxins in Ground

The objective following the present study was to investigate the effect of ultra violet irradiation on aflatoxins in ground and tree nuts. Samples of nuts were randomly selected from the retail market of Faisalabad. The moisture contents of the nuts were artificially increased to 10±3% and 16±3% to facilitate the mold growth. The samples were stored at a room temperature of 25-30 °C for 12 weeks. The stored nut samples were checked after a storage period of 12 weeks, the fungi were found growing in all nuts along with considerable aflatoxins production. Aflatoxins and mold contaminated samples were exposed to UVC radiations of 265nm for 15, 30 and 45 minutes. The fungicidal activity of UVC radiation was more pronounced in nuts adjusted at high moisture level. The order of sensitivity of nuts for fungal disinfection by UVC irradiation was walnut> almond= pistachio> peanuts. There was a proportional decrease in aflatoxins level with increase in exposure time. Complete elimination of aflatoxin G2 was achieved in all nut samples after 15min. exposure, while aflatoxin G1 showed 100% degradation only in almond and pistachio. After 45 min. exposure to UVC, aflatoxin B1 showed maximum reduction of 96.5% in almond and pistachio. The degradation of total aflatoxins as well as that of aflatoxin B1 by UVC irradiation was found to follow first order kinetics.read more

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FARHAT JUBEEN, IJAZ AHMED BHATTI, MUHAMMAD ZARGHAM KHAN, ZAHOOR-UL-HASSAN AND MUHAMMAD SHAHID

Enhanced Decolorization of Reactive black 5 by Lac

Response surface methodology (RSM) was applied for the decolourization of the azo dye Reactive black 5 (RB-5) using commercial laccase from a white rot fungus Trametes versicolor. It was observed that the presence of syringaldehyde is essential for decolourization of RB-5 because laccase alone did not decolorize the dye. Syringaldehyde (SYD) was found to be an effective natural redox mediator. The effect and interaction of dye, mediator, and enzyme concentration on RB-5 decolorization was evaluated by Response Surface Methodology using Box-Behnken design. Seventeen experiments were conducted as designed by the above design and a quadratic model was obtained for dye decolour-ization through this design. The experimental values were in good agreement with predicted values and the model was highly significant, the correlation coefficient being 0.994. SYD showed main effect on RB-5 decolorization whereas enzyme had low effect. The optimum concentration of dye, enzyme and SYD were found to be 84 µM, 53 mg/L and 150.3 µM, respectively for maximum decolourization (92 %) of the dye. The validation experiment also showed good correlation between experimental and predicted responses.read more

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ISMAT BIBI, HAQ NAWAZ BHATTI, MUHAMMAD ARIF AND ABDUL WADOOD

Theoretical Studies on the Reaction Mechanism of V

The reaction mechanism of methanol photocatalytic degradation by nano-titanium dioxide (TiO2) have been studied at the B3LYP/6-311++G (2df, pd) level, and reaction channels have been found. The geometries of all compounds were optimized, the results indicate that the intermediate products are HCOOH and H2O, last products of reaction are CO2 and H2O. Intermediates, transition states and products were optimized and IRC calculations were carried out. The calculated results explain the conclusion of experiment successfully. From the view of bond length and analysis of energy, the changes of chemical bonds in the reactions are discussed, the potential energy of the reaction is low, which is helpful for the experiment of the methanol photocatalytic degradation over nano-TiO2.read more

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HUIMIN BI, FUYING YOU, YAN LIU, XINGQUAN CHAI AND LINGPENG MENG

Biosorption of Cr (VI) ion from Aqueous Solution b

The kinetics, equilibrium and thermodynamic of the biosorption of Cr (VI) ion onto maize husk biomass from aqueous solution were investigated. The effects of contact time, initial metal concentration, pH, temperature as well as modification with oxalic acid on biosorption capacity were studied. The maximum biosorption capacity of the untreated corn shaft biomass (UTCS) was found to be 28.49 mg g-1 which slightly increased to 29.33 mg g-1 when treated with oxalic acid treated corn shaft biomass (ATCS). The kinetics studies showed that the biosorption process of the metal ion fitted well with second order model. The calculated thermodynamic parameters (∆Go, ∆Ho and ∆S◦) showed that the biosorption of Cr (VI) ion onto the biomass maize husk is feasible, spontaneous and exothermic in nature.read more

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ADEOGUN ABIDEEN IDOWU, OFUDJE ANDREW EDWIN, IDOWU MOPELOLA ABIDEMI, AHMED SIKIRU AKINYEYE AND SARAFADEEN OLATEJU KAREEM

Sonophotocatalytic Degradation Kinetics of an Azo

The effect of parameters such as initial concentration of dyestuff, light intensity, presence and the amplitude of ultrasound energy and temperature on sonophotocatalytic degradation kinetics of a monoazo dye amaranth (acid red 27-AR 27) was studied. The sonophotocatalytic degradation rate followed pseudo-first order kinetics with respect to amaranth concentrations. The ultrasound energy did not influence the activation energy. It was observed that the reaction rate accelerated in the presence of ultrasound energy during the experiments. A general equation was obtained for sonophotocatalytic degradation kinetics of amaranth which included the effect of ultrasound energy:read more

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TUBA YETIM AND TANER TEKIN