• فهرس المقالات Equilibrium isotherm

      • حرية الوصول المقاله

        1 - Montmorillonite as Efficient Nanoclay for Removal of Aniline Blue Dye: Optimization, Isotherm and Kinetic Study
        Somayeh Lorzani Shahla Elhami
        In this study, montmorillonite clay was used as the adsorbent for the removal of Aniline Blue dye, from aqueous solution by the batch adsorption technique under different conditions. The maximum removal of aniline blue dye for initial dye concentration 20 mg/L was more أکثر
        In this study, montmorillonite clay was used as the adsorbent for the removal of Aniline Blue dye, from aqueous solution by the batch adsorption technique under different conditions. The maximum removal of aniline blue dye for initial dye concentration 20 mg/L was more than 95% at optimum conditions (pH=4.5, contact time=30 min, and adsorbent dosage=2 g/L). The data of this study were fitted with Langmuir and Freundlich isotherms. Also, kinetic adsorption study showed that for initial dye concentration 50 mg/L, pseudo-second-order kinetic is more favorable. More than 90% removal for Aniline Blue dye showed that this adsorbent is an effective natural compound and also inexpensive for treatment processes. Hence, using this technique and process was recommended for dye pollutants removal from aqueous environments. High removal, simplicity and high adsorption capacity of adsorbent are the main advantages in this method. تفاصيل المقالة
      • حرية الوصول المقاله

        2 - Adsorption of phenol by super hydrophobic phenol-formaldehyde/silica hybrid aerogel
        Mohamad Seraji Sadra Soleimankhani Hossein Abadani Jamal Davarpanah
        Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity and small pore size mean was prepared via sol-gel polymerization under solvent saturated vapor atmosphere and was dried by ambient drying method. The silica sols were prepared based on Tetra أکثر
        Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity and small pore size mean was prepared via sol-gel polymerization under solvent saturated vapor atmosphere and was dried by ambient drying method. The silica sols were prepared based on Tetraethoxysilane (TEOS) and Methyltrimethoxysilane (MTES) as hydrophilic and hydrophobic precursors, respectively. Phenol-formaldehyde resin was used as polymeric phase to achieve suitable physical properties. The contact angle of this aerogel was about 147˚ and it is a result of formation of CH3 groups on the pore walls. The results of FESEM and nitrogen adsorption indicated that the structure of this aerogel is highly porous, uniform, and colloid like network. The Phenol-formaldehyde/silica hybrid aerogel was used for removal of phenol from aqueous solution. The study was carried out as functions of contact time, pH and initial phenol concentration. The experiments demonstrated that maximum phenol removal was obtained at neutral pH in unbuffered condition and it takes 40 min to attain equilibrium. Langmuir, Freundlich and Temkin isotherm models were applied to fit adsorption equilibrium data. The best-fitted data was obtained with the Langmuir model and the adsorbent capacity was 97.09 mg g−1. Kinetic studies indicated that the adsorption process was described better by pseudo-second-order model. تفاصيل المقالة
      • حرية الوصول المقاله

        3 - Adsorption of Phenol by Super Hydrophobic Phenol-Formaldehyde/Silica Hybrid Aerogel
        Mohamad Mehdi Seraji Sadra Soleimankhani Hossein Afkhami Abadani Jamal Davarpanah
        Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity, and thesmall pore size mean was prepared via sol-gel polymerization under solvent saturated vaporatmosphere and was dried by ambient drying method. The silica sols were prepared based onTet أکثر
        Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity, and thesmall pore size mean was prepared via sol-gel polymerization under solvent saturated vaporatmosphere and was dried by ambient drying method. The silica sols were prepared based onTetraethoxysilane (TEOS) and Methyltrimethoxysilane (MTES) as hydrophilic and hydrophobicprecursors, respectively. Phenol-formaldehyde resin was used as organic phase to achievesuitable physical properties. The contact angle of this aerogel was about 147˚ and it is a resultof formation of CH3 groups on the pore walls. The results of FESEM and nitrogen adsorptionindicated that the structure of this aerogel is highly porous, uniform, and colloid like network.The Phenol-formaldehyde/silica hybrid aerogel was used for removal of phenol from aqueoussolution. The study was carried out as functions of contact time, pH and initial phenolconcentration. The experiments demonstrated that maximum phenol removal was obtainedat neutral pH in unbuffered condition and it takes 40 min to attain equilibrium. Langmuir,Freundlich and Temkin isotherm models were applied to fit adsorption equilibrium data. Thebest-fitted data was obtained with the Langmuir model and the adsorption capacity was 97.09mg g−1. Kinetic studies indicated that the adsorption process was described better by pseudosecond-order model. تفاصيل المقالة
      • حرية الوصول المقاله

        4 - Response Surface Modeling and Optimization of Effective Parameters for Zn(II) Removal From Aqueous Solution Using Gracilaria Corticata
        Farah Assadian Ali Niazi Majid Ramezani
        Biosorption of Zn(II) from aqueous solution by biomass marine alga, namely Gracilaria corticata was investigated in this paper. Four independent variables, including initial zinc concentration (50-150 mg L-1), initial solution pH (3-7), contact time (10-50 min), and bio أکثر
        Biosorption of Zn(II) from aqueous solution by biomass marine alga, namely Gracilaria corticata was investigated in this paper. Four independent variables, including initial zinc concentration (50-150 mg L-1), initial solution pH (3-7), contact time (10-50 min), and biomass amount (1-2 g/100mL) were studied in the biosorption process. Optimization of the process conditions for maximizing Zn(II) removal from aqueous solutions by Gracilaria corticata was carried out using Box-Behnken design, including response surface methodology (RSM) based on 27 different experimental data. The optimal operating conditions for 95.0% removal of Zn(II) were as follows: initial zinc concentration of 100 mg L-1, initial solution pH of 5, contact time of 30.5 min, and biomass amount of 2 g/100 mL. In addition, the equilibrium isotherms were described by investigation of Langmuir and Freundlich isotherms. The Freundlich adsorption isotherm model well matched the experimental data (R2 = 0.981). The kinetic data fitted pseudo-second order model with a correlation coefficient of 0.9953. Gracilaria corticata was found to be well applicable for zinc removal based on the experimental results. تفاصيل المقالة