Aref Shokri; Safoora Krimi
Abstract
In this study, the TiO2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in aqueous media. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), field emission scanning electron microscopy ...
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In this study, the TiO2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in aqueous media. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction (XRD). The central composite design (CCD) was employed for experimental design. The effect of operative variables including contact time, photocatalyst dosage and pH were investigated. The ANOVA (analysis of variance) studies displays the second-order regression model and a high determination coefficient value (R2 = 0.9953, R2pred = 0.9642, R2adj = 0.9910) for the destruction of AR18 was obtained. The contour plots were applied to study the shares of each variable and their interactions on the degradation of AR18. The optimal circumstances predicted by the model were as the following: the catalyst concentration at 0.88g/L, pH at 6.5, and contact time in 125 min. In this situation, the predicted and actual dye removal were 98.5% and 96.3%, respectively. The removal of COD (chemical oxygen demand) after 125 min was 53% indicating, the notable performance of photocatalyst in mineralization of AR18.
siroos shojaei; Jamal Ahmadi; Meysam Davoodabadi Farahani; Bentolhoda Mehdizadehd; Mohammadreza Pirkamali
Abstract
The remaining dye in the wastewater is not desirable as it damages the ecosystem and nature, and also is very toxic. The Crystal Violet (CV) dye is toxic and potentially carcinogenic. In addition, it reduces light in water and prevents the process of photosynthesis of aquatic plants. Therefore, nanozeolite-X ...
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The remaining dye in the wastewater is not desirable as it damages the ecosystem and nature, and also is very toxic. The Crystal Violet (CV) dye is toxic and potentially carcinogenic. In addition, it reduces light in water and prevents the process of photosynthesis of aquatic plants. Therefore, nanozeolite-X (NX) was utilized as an adsorbent to remove the CV; effects of pH, catalyst mass, sonication time, and concentration of dye were also investigated. Effects of variables on the removal efficiency were studied via the Central Composite Design (CCD) to determine the dye removal percentage. The quadratic model was selected to predict the removal efficiency using the software. Optimal conditions for CV removal from aqueous solution were: pH= 8, sonication time= 6 min, concentration of dye= 13 mg L-1, and catalyst mass= 0.26 g. In these circumstances, the recovery efficiency was 97.60%. The research results indicated that NX could be applied potentially for CV removal.
Kamal Alizadeh; Esmail Khaledyan; Yagoub Mansourpanah
Abstract
In this study, a selective, fast and novel magnetic mesoporous silica sorbent Fe3O4@MCM-41-NH2, was synthesized, functionalized and has been used for the removal of Pb+2 ions from aqueous solution. The characteristics of the Fe3O4@MCM-41-NH2 sorbent was investigated by XRD, VSM, SEM, TEM, ...
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In this study, a selective, fast and novel magnetic mesoporous silica sorbent Fe3O4@MCM-41-NH2, was synthesized, functionalized and has been used for the removal of Pb+2 ions from aqueous solution. The characteristics of the Fe3O4@MCM-41-NH2 sorbent was investigated by XRD, VSM, SEM, TEM, BET, and FT-IR. The response surface methodology (RSM) based on central composite design (CCD) was utilized for estimating the effects of parameters, namely contact time (min), pH, the quantity of adsorbent (g) and initial concentration of Pb+2. The quadratic model was used as the best model for guessing variables. The results of the analysis of variance for this model were obtained with a high F-value (50.28), very low P-value (<0.0001) and non-significant lack of fit (0.2251). The maximum adsorption capacity was obtained at 46.08 mg/L. Fitting equilibrium data with different isotherm models shows that Freundlich isotherm was the best-fitted model. The pseudo-second-order model was the best model for fitting experimental data.