Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechan...Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide(RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10-20 nm are well dispersed over the RGO nanosheets, resulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore,with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.展开更多
A magnetic adsorbent can be easily recovered from treated water by magnetic force, without requiring further downstream treatment. In this research, amine-functionalized silica magnetite has been synthesized using N-...A magnetic adsorbent can be easily recovered from treated water by magnetic force, without requiring further downstream treatment. In this research, amine-functionalized silica magnetite has been synthesized using N-[3-（trimethoxysilyl）propyl]-ethylenediamine （TPED） as a surface modification agent. The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system, and the maximum adsorption was found to occur at pH 5.5± 0. 1. The adsorption equilibrium data fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg/g. A pseudo second-order model could best describe the adsorption kinetics, and the derived activation energy was 26.92 kJ/mol. The optimum condition to desorb Cu2＋ from NH2/SiO2/Fe304 was provided by a solution with 0.1 mol/L HNO3.展开更多
基金financially supported by National Natural Science Foundation of China (No. 21377084)Shanghai Municipal Natural Science Foundation (No. 13ZR1421000)
文摘Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorption mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide(RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10-20 nm are well dispersed over the RGO nanosheets, resulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore,with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.
文摘A magnetic adsorbent can be easily recovered from treated water by magnetic force, without requiring further downstream treatment. In this research, amine-functionalized silica magnetite has been synthesized using N-[3-（trimethoxysilyl）propyl]-ethylenediamine （TPED） as a surface modification agent. The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system, and the maximum adsorption was found to occur at pH 5.5± 0. 1. The adsorption equilibrium data fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg/g. A pseudo second-order model could best describe the adsorption kinetics, and the derived activation energy was 26.92 kJ/mol. The optimum condition to desorb Cu2＋ from NH2/SiO2/Fe304 was provided by a solution with 0.1 mol/L HNO3.
