NOPR Collection:

Adsorptive removal of lead ion from aqueous solution by activated carbon/iron oxide magnetic composite

Tue, 01 Mar 2016 00:00:00 GMT

Title: Adsorptive removal of lead ion from aqueous solution by activated carbon/iron oxide magnetic composite Authors: Yao, Shuhua; Sun, Shuyu; Wang, Shuo; Shi, Zhongliang Abstract: The adsorption features of activated carbon and the magnetic properties of iron oxides have been combined in a composite to produce magnetic adsorbents. These magnetic particles can be used as adsorbent for the removal of heavy metals such as lead from aqueous solution and can subsequently be removed from the medium by a simple magnetic procedure. The prepared samples have been characterized by SEM, N₂ adsorption–desorption and powder XRD. The results show that the presence of iron oxides caused a decrease in the surface area and microporous volume of the activated carbon. The effects of initial solution pH, contact time, adsorbent dosage and initial concentration of lead ion on the adsorption behaviour of lead ion onto the synthetic magnetic adsorbent have been investigated. Kinetic studies show that the overall adsorption rate of lead ion is illustrated well by the pseudo-second-order kinetic model. The applicability of the Langmuir and Freundlich models for the lead ion adsorption data is tested. The results show that the Langmuir equation gives a better fit than Freundlich equation to the adsorption isotherms. Moreover, the prepared composite exhibits paramagnetic behaviours and could be easily recovered from the medium by a simple magnetic process. It can therefore be potentially applied for the treatment of water contaminated by heavy metal pollutants. Page(s): 146-152

Solar photocatalytic treatment of gelatin industry effluent: Performance of pilot scale reactor with suspended TiO₂ and supported TiO₂

Tue, 01 Mar 2016 00:00:00 GMT

Title: Solar photocatalytic treatment of gelatin industry effluent: Performance of pilot scale reactor with suspended TiO₂ and supported TiO₂ Authors: Velmurugan, R; Subash, B; Krishnakumar, B; Selvam, K; Swaminathan, M Abstract: Degradation of gelatin in the effluent by heterogeneous photocatalysis using suspended and supported TiO₂ in falling film photoreactor under natural solar light has been investigated. Suitable weight proportions of slurry comprising fevicol and home-made TiO₂ have been prepared and the fevicol TiO₂(F-T) film on acrylic sheet is obtained by brush coating. TiO₂ coating containing 10 wt% fevicol is found to be more adherent and efficient for gelatin degradation. This F-T catalyst in the falling film photoreactor has been tested for the treatment of effluent and its efficiency is compared with suspended homemade TiO₂. The effects of operational parameters such as the amount of TiO₂, effluent concentration, and initial pH on treatment process by F-T coating as well as by suspended TiO₂ slurry have been analyzed. The F-T film is efficient for repeated treatment of effluent when compared to suspended TiO₂. Hence this cost effective solar photocatalytic process is widely applicable at industrial scale. Page(s): 139-145

Corrosion inhibition of steel in sulphuric acid by aqueous extracts of Rose and Rose water

Tue, 01 Mar 2016 00:00:00 GMT

Title: Corrosion inhibition of steel in sulphuric acid by aqueous extracts of Rose and Rose water Authors: Al-Turkustani, Aisha M Abstract: The corrosion inhibition of steel in 2 molar sulphuric acid solution by Rose extract and/or Rose water has been studied at 30°C using chemical (weight loss and hydrogen evolution) and electrochemical (impedance and polarization) measurements. It is found that all methods give consistent results, the inhibition efficiency increases with increasing concentration of the extract, and it shows that rose extract is a better corrosion inhibitor for steel than rose water. The polarization curves indicate that rose extract and rose water act as mixed-type inhibitors. The adsorption of inhibitor on the steel surface is found to obey the Langmuir adsorption isotherm model for rose extract and Freundlich adsorption isotherm for both rose extract and rose water. Thermodynamic data for the adsorption process (K_ads and G°_ads) were calculated and discussed. Page(s): 131-138

Prediction of AHAS inhibition by sulfonylurea herbicides using genetic algorithm and artificial neural network

Tue, 01 Mar 2016 00:00:00 GMT

Title: Prediction of AHAS inhibition by sulfonylurea herbicides using genetic algorithm and artificial neural network Authors: Saidi, A; Mirzaei, M Abstract: Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) catalyzes the first common step in branched-chain amino acid biosynthesis. The enzyme is inhibited by several chemical classes of compounds and this inhibition is the basis of action of the sulfonylurea herbicides. The negative logarithm inhibition constant (pKi) of 68 sulfonylurea analogs as inhibitors of pure AHAS using quantitative structure–activity relationship (QSAR) has been calculated. Suitable set of molecular descriptors are calculated and the important descriptors are selected by genetic algorithm and stepwise multiple regression methods. These variables serve as inputs to generated neural networks. After optimization and training of the networks, they are used for the calculation of pKi for the prediction set. Comparison between the results obtained, show the superiority of genetic algorithm over stepwise multiple regression method in feature-selection. For network that used the genetic algorithm for feature-selection methods there are very good agreements between calculated and experimental pKi for data set. The correlation coefficient between calculated and experimental values of pKi for training and prediction set are 0.988 and 0.954, respectively. Page(s): 121-130

NOPR Collection:

Adsorptive removal of lead ion from aqueous solution by activated carbon/iron oxide magnetic composite

Solar photocatalytic treatment of gelatin industry effluent: Performance of pilot scale reactor with suspended TiO2 and supported TiO2

Corrosion inhibition of steel in sulphuric acid by aqueous extracts of Rose and Rose water

Prediction of AHAS inhibition by sulfonylurea herbicides using genetic algorithm and artificial neural network

Solar photocatalytic treatment of gelatin industry effluent: Performance of pilot scale reactor with suspended TiO₂ and supported TiO₂