Sultan Alam

Effect of aqueous leaf extract of common lambsquarters (Chenopodium album L.) and NaCl on germination and seedling growth of rice

Aqucous leaf extract of common lambsquarters (Chenopodium album L.) was evaluated alone or in combination with NaCl for its effect on germination and rice seedling growth. The treatments have no effect on germination. However, growth of both shoot and root significantly decreased under NaCl alone and in combination with leaf extract. Root growth was affected more than the shoot and the effect of NaCl was accentuated in the presence of leaf extract.

Investigating the Catalytic Activity of Monoclinic Zirconia; Oxidation of Benzyl Alcohol in Aqueous Medium at Mild Conditions

Abstract The oxidation/degradation of benzyl alcohol in artificially contaminated water under atmospheric pressure by molecular oxygen/air over ZrO2(m) catalyst was investigated. Monoclinic phase ZrO2 was synthesized and characterized by modern techniques. Oxidation of benzyl alcohol in aqueous medium was carried out in a typical three necked double walled batch reactor equipped with thermometer and condenser. The rate of oxidation was affected by different reaction parameters such as speed of agitation, catalyst loading, temperature, concentration of substrate solution (46.3 – 185 mmol/L) and partial pressure of oxygen. Major products were detected with GC and UV spectrophotometer. Optimal conditions were setup for better catalytic activity of ZrO2(m). To sum up, catalytic oxidation of benzyl alcohol in aqueous medium by ZrO2(m) is a useful and cheaper method for the conversion of benzyl alcohol to valuable products as well as for the removal of benzyl alcohol from industrial waste water.

Removal of Lead from Aqueous Solution by an Efficient Low Cost Biosorbent

Abstract Removal of Pb(II) ion from aqueous solution on modified sawdust obtained from Morus alba was investigated. The sample was characterized by BET surface area, EDX, FTIR and Zeta potential technique. The surface contains carbonyl and hydroxyl functional groups which act as binding sites for Pb(II) ion. Adsorption kinetics of Pb(II) on sawdust was tested by pseudo first order, Elovich and parabolic diffusion kinetic equations. The adsorption data were found to fit to Freundlich, Langmuir and Tempkin isotherms. The rate of adsorption was high at high temperature. Thermodynamic parameters like ΔH, ΔS and ΔG were calculated from the kinetic data. The positive values of ΔS reflect some structural exchange among the active site of the adsorbent and metal ion. The negative values of Gibbs free energy (ΔG) show the spontaneous nature of the process.

Removal of Triphenylmethane Dye from Aqueous Solution by Carbonaceous Adsorbent

Abstract Removal of acid blue 1 from aqueous solution on activated carbon produced from Salvadora oleoides was investigated. The samples were characterized by BET surface area, BJH pore volume and pore diameter, XRD, SEM, EDS and FTIR analysis. The surfaces contain functional groups like ketones and hydroxyl which disappeared at high activation temperature; relatively high amount of carbon w.r.t. oxygen was found with the increase in activation temperature; the increase in surface area and development of porous structures showed a positive effect on the adsorption capacity. Adsorption of the dye on carbon at 10 and 45°C showed that the first order, Bangham and Elovich and parabolic diffusion equations apply to the kinetic data. The adsorption rate increased with the temperature and with thermal activation of the sample. Thermodynamic parameters like ΔE≠, ΔH≠, ΔS≠ and ΔG≠ were calculated from the kinetic data. The negative values of ΔS≠ reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (ΔG≠), which represents the driving force for the affinity of dye for the carbon, increased with the increase in activation temperature.

Adsorptive Removal of Ni2+ from Aqueous Solution by Low Cost Cellulosic Adsorbent-Adsorption Kinetics and Isotherm Study

Abstract Adsorptive removal of Ni2+ from aqueous solution by low cost cellulosic adsorbent was investigated with respect to adsorption kinetics and adsorption isotherm. Adsorbent was characterized by BET surface area, SEM, EDX, FTIR and Zeta potential technique and reported earlier. The surfaces contain carbonyl and hydroxyl functional groups, which act as binding sites for Ni2+ ion. Adsorption kinetics of Ni2+ was tested by first order, Elovich, parabolic diffusion and Bangham kinetic equations. Thermodynamic parameters like ΔH≠, ΔS≠ and ΔG≠ were calculated from the kinetic data. The rate of adsorption was high at high adsorption temperature. Positive values of ΔS≠ reflect some structural exchange among the active site of the adsorbent and metal ion. Freundlich, Langmuir, Temkin isotherms and distribution coefficient were found fit to the adsorption isotherm data.

Investigating the Activity of Zirconia as a Catalyst and a Support for Noble Metals, in Green Oxidation of Cyclohexane

Abstract Green oxidation of cyclohexane by molecular oxygen was carried out over ZrO2 and noble metals (Pd and Pt) supported on zirconia in solvent free conditions. Studies have been carried out in a typical three-necked batch reactor. Reaction products were identified by GC and UV spectrophotometer. Reaction rates were determined as a function of temperature, partial pressure of oxygen, amount of catalyst, volume of reactants, agitation and reaction duration. The agitation effect and activation energy revealed the absence of mass transfer resistance. Experimental results unveiled the effect of morphology of ZrO2 on catalysis. 1.0 wt.% noble metal/ZrO2(m) was found more selective for cyclohexanol production at low temperature, agitation 900rpm and partial pressure of 101.325 KPa while at high temperature cyclohexanol was further oxidized to cyclohexanone. Comparison of Pt/ZrO2 and Pd/ZrO2 catalysts was made on the basis of reactivity and selectivity. Catalysts were characterized by using BET surface area and pore size analyzer, XRD and SEM. To conclude shortly, for the oxidation of cyclohexane, platinum or palladium supported on zirconia are selective, recyclable and could behave as truly heterogeneous catalysts.

Adsorption Studies of Basic Green 4 from Aqueous Solution on Ca2+ Exchanged Clay

Abstract The adsorption of basic green 4 from aqueous solution on calcium exchanged clay (Attock-Ca and Swat-Ca) was studied. Clays were first purified and activated with H2SO4 and then exchanged with Ca2+ ions. Clay was characterized by BET surface area, XRD and SEM/EDS. The adsorption kinetic at 298 K and 306 K showed that the first order models were applied to the data. The rate constant increased with the rise in temperature of adsorption/activation. Thermodynamic properties (ΔE≠, ΔH≠, ΔS≠ and ΔG≠) for the adsorption process were calculated. Positive values of ΔH≠ showed that the adsorption of basic green 4 is endothermic. Positive values of ΔS≠ reflected the increase in the disorder of the system at the solid-solution interface during adsorption. The Gibbs free energy, which is the driving force for adsorption is negative indicating spontaneous adsorption. Freundlichs and Langmuirs models described the equilibrium adsorption study and found to fit the experimental data.

Zirconia Supported Iron as an Efficient Green Catalyst for the Selective Liquid Phase Solvent Free Oxidation of Alcohol with Molecular Oxygen

Abstract Liquid phase oxidation of alcohol to corresponding aldehyde and ketone in solvent free condition with molecular oxygen, at mild temperature and pressure was studied in a self-designed three necked batch reactor, using iron supported on zirconia as a catalyst. The catalyst was prepared by incipient wetness technique, reduced in hydrogen flow and characterized by X-ray Diffractometry, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Thermo Gravimetric and Differential Thermal Analysis, Fourier Transform Infrared Spectroscopy, particle size analyzer, surface area and pore size analyzer. Effects of different parameters such as temperature and time on the rate of reaction were studied. It was observed that the reduced catalyst showed higher catalytic activity and selectivity than the unreduced catalyst for the liquid phase oxidation of alcohols to corresponding aldehydes and ketones.