In this study, MCM-48 mesoporous silica was functionalized with dendrimer amines based on [1,3,5]-triazines (DA-S-Triazines), characterized by FT-IR, XRD, TEM and N2 sorption-desorption isotherm. The results confirmed the successful graft of organic functional groups on the MCM-48 surface. Then, it was used for the selective sorption of Ag (I) from aqueous solution and real wastewater in the batch system. The effect of main parameters on equilibrium sorption capacity and removal percentage including sorbent dose, pH, contact time, initial metal ion concentration and temperature was investigated. The results showed that the sorption of Ag (I) by DA-S-Triazines@MCM-48 was pH independent in the range of 3–8. The sorption capacity of MCM-48 strongly increases from 7.23 to 123 and 169.49 mg/g for HDA-S-Triazines@MCM-48 and DA-S-Triazines@MCM-48, respectively. The equilibrium data were fitted to nonlinear Freundlich, Temkin and Langmuir models, while a better fit was obtained by Freundlich model. According to the kinetic parameters, the sorption process was rapid. To selective sorption of Ag (I) from aqueous solution and real wastewater, the pore size of MCM-48 was exactly adjusted by changing the amount of DA-S-Triazines ligand. The results illustrated that the selective sorption of Ag (I) increased by increasing the amount of DA-S-Triazines ligand grafted on MCM-48 mesoporous silica. The results of sorption-desorption proved the economic synthesis and practical application of DA-S-Triazines@MCM-48 for sorption of Ag (I) from wastewater. DA-S-Triazines@MCM-48 as a potential sorbent showed high sorption capacity for sorption of Ag (I) from electroplating industry wastewater.
Hosseini Asl, S.; Masomi, M.; Hosseini, M.; Javadian, H.; Ruiz, M.; Sastre, A. Process safety and environmental protection Vol. 107, p. 153-167 DOI: 10.1016/j.psep.2017.02.012 Data de publicació: 2017-04-01 Article en revista
The aim of this research was to estimate the possibility of using synthesized hydrous iron oxide/aluminium hydroxide composite loaded on coal fly ash (FA3) as an efficient sorbent for Cr(VI) sorption from aqueous solution. In this regard, dissolution and precipitation processes were performed to rearrange and load the intrinsic iron and aluminum on the surface of fly ash. Different characterization techniques including XRD, XRF, FT-IR, SEM, LPS and BET surface area were applied to analyze the sorbent properties. Moreover, sorption kinetics were studied using Morris–Weber intra-particle diffusion, Lagergren pseudo-first-order and pseudo-second-order models. The kinetic analyses indicated that pseudo-first-order model controlled the sorption process. In order to estimate the sorbent capacity, Langmuir, Freundlich and D–R models were applied. The thermodynamic parameters of Cr(VI) sorption were also studied. In addition, removal efficiency of Cr(VI) was predicted using the developed fuzzy logic model. The fuzzification of four input variables including pH, contact time, adsorbent dose and initial Cr(VI) concentration versus removal efficiency as output was carried out using an artificial intelligence-based approach. A Mamdani-type fuzzy interface system was employed to fulfill a collection of 24 rules (If-Then format) using triangle membership functions (MFS) with seven levels in fuzzy sets. The proposed fuzzy logic model demonstrated high predictive performance with correlation coefficient (R2) of 0.95 and acceptable deviation from the experimental data, confirming its suitability to predict Cr(VI) removal efficiency. Based on experimental data and statistical analysis, the synthetized sorbent was effective for treating wastewater containing Cr(VI).