1,018 research outputs found
Synthesis of bis[(4,10-diaza-4,10-ditosyl-benzo-12-Crown-4) 4'-yl] diaminoglyoxime and its complexes
No full textRECOVERY OF SILVER FROM AQUEOUS SOLUTION BY WATER HYACINTH (EICHHORNIA CRASSIPES) ROOTS
No full textRoots of water hyacinth, Eichhornia crassipes, were found to have biosorption capacity for silver. To evaluate the biosorption capacity and characteristics, the effect of solution pH, dose of biosorbent loading, contact time, temperature and initial silver concentration were investigated in a batch mode. The Langmuir and Freundlich adsorption models were used for mathematical description of the sorption equilibrium. Equilibrium data was fitted to the Langmuir model at 293 and 398 K and concentrations of 10-150 mg L-1. Based on the Langmuir isotherm plots, the maximum biosorption capacity value was calculated to be 141.54 mmol g(-1) at 293 K. Various thermodynamic parameters, such as Delta G degrees, Delta H degrees, and Delta S degrees, were evaluated with results indicating that this system was an exothermic spontaneous reaction and kinetically suited to pseudo second order model
Disperse Dyeability of Polypropylene Fibres via Microwave and Ultrasonic Energy
No full textIn this study, the dyeability of polypropylene fibres with a disperse dye via microwave and ultrasonic energy was examined. A dye bath having a liquor-to-goods ratio of 20:1, and including dyestuff 2% owf was prepared and dyeing experiments using microwave and ultrasonic energy were carried out. In the case of microwave dyeing, experiments have been carried out at different energy levels (L, M-L, M, M-H and H) and different time ranges (1 to 5 min) while in the case of ultrasonic energy different temperatures (20, 40, 60 and 80 degrees C) and different time range (1 min to 30 min) were used. Additionally, effect of carrier was also investigated. Dyed samples were examined by determining their K/S values. Diffusion coefficients in all methods were calculated using Shibusawa's approximation of Hill's equation. Washing fastnesses of dyed samples were also examined. This study showed that the dyeability of polypropylene fibres was increased by both microwave and ultrasonic energy
Synthesis of [(4,10-diaza-4,10-ditosylbenzo-12-crown-4)-4'-yl] salicylaldimine and its metal complexes
No full textThe synthesis of a new Schiff base ligand (HL) formed by the condensation of salicylaldehyde with 4'-amino-4,10-diaza-4,10-ditosylbenzo-12-crown-4 is described. The complexation of this ligand with Ni(II), Cd(II), Cu(II), Co(II) and UO2(VI) was investigated by potentiometric titration. The results indicate that Cu(II), Ni(II), Co(II), Cd(II), UO2(VI) give complexes with the metal-ligand ratio of 1:1. The order of the formation constants of the mononuclear complexes is Ni(II) > Cd(II) > Cu(II) > Co(II) > UO2(VI)
BIOSORPTION OF CATIONIC DYES FROM AQUEOUS SOLUTION BY WATERHYACINTH ROOTS
No full textWater hyacinth Eichhomia crassipes was found to have biosorption capacity for cationic dyes, malachite green and methylene blue from aqueous solutions. To evaluate the biosorption capacity and characteristics, the effect of solution pH, initial dye concentration, temperature, dose of biosorbent loading, contact time and shaking rate were investigated in a batch mode. Biosorption was increased with the increasing temperature for both studied dyes. The Langmuir and Freundlich adsorption models were used for mathematical description of the sorption equilibrium. Equilibrium data was fitted well to the Langmuir model in the studied concentrations (1-200 mg L-1) at 293 and 313 K. Based on the Langmuir isotherm plots the maximum biosorption capacity values were calculated to be 44.64 mg g(-1) for malachite green and 42.55 mg g(-1) for methylene blue at 313 K. Various thermodynamic parameters such as Delta G degrees, Delta H degrees, and Delta S degrees were evaluated with results indicating that this system was an endothermic spontaneous reaction and kinetically suited to pseudo-second-order model
Removal of Rhodium (III) from Aqueous Solution by Na- and K-Treated Clinoptilolites
No full textThe clinoptilolite which was modified with sodium and potassium chloride was found to have adsorption capacity for rhodium. To evaluate the adsorption capacity and characteristics, the effects of solution pH, dose of clinoptilolite loading, contact time, temperature, and initial rhodium concentration were investigated in a batch mode. Adsorption was decreased with the increasing temperature for both modified clinoptilolites. The Langmuir and Freundlich adsorption models were used for mathematical description of the adsorption equilibrium. Equilibrium data were fitted to the Langmuir model in the concentrations of 2-60 mg l(-1) at 293 and 313 K. Based on the Langmuir isotherm plots, the maximum adsorption capacity value was calculated to be 0.415 mg g(-1) at 293 K. Various thermodynamic parameters such as a dagger GA degrees, a dagger HA degrees, and a dagger SA degrees were evaluated with results indicating that this system was an exothermic spontaneous reaction and kinetically suited to the pseudo-second-order model
ADSORPTION OF SOME TEXTILE DYES ON ACTIVATED CARBON PREPARED FROM RICE HULLS
No full textThe removal of textile dyes (CI acid blue 40 and CI basic blue 41) from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH), have been investigated depending on pH, activated carbon dosage, contact time and initial concentration. The optimum values of pH, contact time and activated carbon dosage at 75 mg/L initial concentration and 100 mL volume of the dyes solutions have been determined as 2-9, 20 min and 0.25 for CI basic blue 41 and 2-6, 40 min. and 0.50 g for CI acid blue 40, respectively. Freundlich and Langmuir equations were applied for the adsorption of both dyes and their adsorption followed both isotherms. Adsorption capacity has been found as 130.87 and 53.55 mg/g for CI basic blue 41 and CI acid blue 40 from Langmuir isotherms, respectively
Adsorption of cobalt by activated carbon from the rice hulls
No full textThe removal of cobalt (II) ion from aqueous solutions, by adsorption on activated carbon prepared from the rice hulls (ACRH), has been investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time have been determined as 6-7, 1.5 g ACRH/50 mt solution and 40 minutes respectively. Freundlich and Langmuir isotherm constants have been calculated at two different temperatures of 293 K and 313 K. Furthermore the other thermodynamic data for Delta G degrees and Delta S degrees, have been also calculated at two temperatures of 293 K and 313 K. The adsorption of Co (II) ion from aqueous solutions has been found to be exothermic (Delta H degrees=-1.543 KJ/mol)
Adsorption of copper and cadmium ions by activated carbon from rice hulls
No full textThe removal of copper (II) and cadmium (II) ions from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH); was investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time were determined to be 5-8, 0.5 g ACRH/25 mt solution an 60 minutes respectively for the adsorption of Cu (II) ions and 5-8, 1.5 g ACRH/25 mt solution and 60 minutes for the adsorption of Cd (II) ions. From the initial concentrations, the constants for the Freundlich and Langmuir isotherm were calculated at 293 K and 313 K. The adsorption of Cu (II) and Cd (II) ions from aqueous solutions was found to be exothermic [Delta H degrees=-13.474 KJ/mol for Cu (II) and Delta H degrees=-2.302 KJ/mol for Cd (II)]. Furthermore, the other thermodynamic data for Delta G degrees and Delta S degrees, were also calculated at 293 K and 313 K
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