Chemical Engineering
A. Alipour; S. Zarrinabadi; A. Azimi; M. Mirzaei
Abstract
Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology ...
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Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology (RSM) with a Central-Composite Design. The effects of solution pH, contact tie, initial Pb(II) concentration, adsorbent dosage and temperature on the removal efficiency were evaluated. Analysis of variance (ANOVA) was employed to find which parameter has a significant effect on the removal efficiency. The best removal efficiency value was found to be at the initial solution pH of 6.5, temperature of 34°C, initial ion concentration of 100 mg/L and the adsorbent dosage of 0.74 g/L. At this condition, the removal efficiency of Pb(II) ions was 92.54%. The adsorption equilibrium data fitted well with Langmuir isotherm model and the adsorption process followed the pseudo-second-order and intra-particle diffusion kinetic model. Thermodynamic analysis suggests that the adsorption process is endothermic, with an increasing entropy and spontaneous in nature. Besides, the nanocomposite was reused in four successive adsorption–desorption cycles, revealing a good regeneration capacity of the adsorbent. The effects of coexist cation ions on the adsorption of Pb(II) under optimal condition was also investigated. All the results demonstrate that nanocomposite is a potential recyclable adsorbent for hazardous metal ions in wastewater system.
A. K. Ojha; M. Tiwari
Abstract
The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize ...
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The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize the Century pulp and paper mill effluent. Among four bacterial strains, three bacterial strains Bacillus subtilis, Bacillus endo-phyticus, Bacillus sp. were capable of ligninolytic activity. Consortium made by these bacterial strains enhances the degradation of lignin as well as decolorization. Various nitrogen source, carbon source, pH, temperature and low molecular weight organic acids were used in the optimization process of decolorization and degradation of lignin in paper mill effluent. Maximum decolorization 68.29% was found at pH 7.92, temperature 33°C, in the presence of glucose (as carbon source) 0.99% and yeast extract (as nitrogen source) 0.36% when it was optimized through response surface methodology.