Numan Hoda

Adsorption/electrosorption of catechol and resorcinol onto high area activated carbon cloth.

Removal of catechol and resorcinol from aqueous solutions by adsorption and electrosorption onto high area activated carbon cloth (ACC) was investigated. Kinetics of both adsorption and electrosorption were followed by in-situ UV-spectroscopic method and the data were treated according to pseudo-first-order, pseudo-second-order and intraparticle diffusion models. It was found that the adsorption and electrosorption of these compounds onto ACC follows pseudo-second-order model. pH changes during adsorption and electrosorption were followed and discussed with regard to the interaction between ACC and adsorbate molecules, utilizing the pH(pzc) value of ACC. An electrodesorption experiment was conducted to explore the possibility of regeneration of ACC. Adsorption isotherms were derived at 25 degrees C on the basis of batch analysis. The fits of experimental isotherm data to the well-known Freundlich, Langmuir and Tempkin models were examined.

Optimization of Biodiesel Production from Cottonseed Oil by Transesterification Using NaOH and Methanol

Abstract In this study, the transesterification of cottonseed oil with methanol was carried out using NaOH. The parameters, such as molar methanol:oil ratio, NaOH %, and temperature effecting the yield and biodiesel quality, were investigated to optimize biodiesel production from cottonseed oil. Below 50°C, transesterification of cottonseed oil was not completed at any molar methanol:oil ratios and catalyst percentages in 1 h. In 3:1 methanol:oil ratio, full conversion was not observed. Optimum conversion was obtained at 6:1 methanol:oil ratio and at temperatures between 50 and 60°C. Above 60°C, some difficulties were encountered in the washing step. Biodiesels that were produced at different molar methanol:oil ratios, NaOH concentrations, and temperatures were tested according to accepted standard methods and the results were compared with standard values.

Supramolecular chemosensor for selective detection of iron in aqueous medium

We have successfully developed a ‘turn-on’ colorimetric chemosensor for Fe3+ based on 1,10-phenanthroline. An amide derivative of 1,10-phenanthroline 4 was developed for the selective recognition of Fe3+ over Co2+, Cr3+, Cu2+, Mn2+, Ni2+, Ag+ and Zn2+ and could measure Fe3+ concentration in the range of 15–210 μM by UV–vis spectroscopy. Moreover, the addition of Fe3+ to a colourless solution of 4 turned its colour to light pink, indicating that 4 is capable of detecting Fe3+ by the naked eye. Compound 4 exhibits a major absorption band centred at 268 which shifted to 278 nm after addition of Fe3+, and a shoulder band around 514 nm was also observed. The complexation of Fe3+ with 4 was analysed at a different pH and favourable binding was observed at pH 6.2.

Removal of Catechol and Resorcinol from Aqueous Solution by Adsorption onto High Area Activated Carbon Cloth

Removal of catechol and resorcinol from aqueous solutions by adsorption onto high area activated carbon cloth (ACC) was investigated. Kinetics of adsorption was followed by in-situ uv-spectroscopy and the data were treated according to pseudo-first-order, pseudo-second-order and intraparticle diffusion models. It was found that the adsorption process of these compounds onto ACC follows pseudo-second-order model. Furthermore, intraparticle diffusion is effective in rate of adsorption processes of these compounds. Adsorption isotherms were derived at 25 ° C on the basis of batch analysis. Isotherm data were treated according to Langmuir and Freundlich models. The fits of experimental data to these equations were examined.