The remediation of wastewater requires treatment technologies which are robust, efficient,simple to operate and affordable such as adsorption. Lately, three-dimensional(3D)graphene based materials have attracted signi...The remediation of wastewater requires treatment technologies which are robust, efficient,simple to operate and affordable such as adsorption. Lately, three-dimensional(3D)graphene based materials have attracted significant attention as effective adsorbents for wastewater treatment. The intrinsic properties of 3D graphene structure such as large surface area and interconnected porous structure can facilitate the transport of pollutants into the 3D network and provide abundant active sites for trapping the pollutants. For the synthesis of 3D graphene structure, ice-templating is commonly practiced due to its facile steps, cost effectiveness and high scalability potential. This review covers the icetemplating fabrication technique for 3D graphene based materials and their application as adsorbents in eliminating dyes and heavy metals from aqueous media. The assembly mechanisms of the ice-templating fsynthesis are comprehensively discussed. Further discussion on the fundamental principles, critical process parameters and characteristics of ice-templated 3D graphene structures is also included. A thorough review on the mechanisms for batch adsorption of dyes and heavy metals is presented based on the structures and properties of the 3D graphene materials. The review further evaluates the dynamic adsorption in packed columns and the regeneration of 3D graphene based materials.展开更多
Water contamination by non-steroidal anti-inflammatory drugs,such as acetaminophen,is an emerging ecological concern.In this study,a newthree-dimensionalmanganese dioxideengrafted reduced graphene oxide(3D MnO_(2)/rGO...Water contamination by non-steroidal anti-inflammatory drugs,such as acetaminophen,is an emerging ecological concern.In this study,a newthree-dimensionalmanganese dioxideengrafted reduced graphene oxide(3D MnO_(2)/rGO)hybrid aerogel was developed for acetaminophen sequestration.The synthesis involved firstly the self-assembly of GO aerogel,followed by thermal reduction and in-situ MnO_(2) growth by redox-reaction.The aerogel demonstrated interlinked planes with smooth surfaces deposited with MnO_(2) nanospheres and pores of 138.4–235.3μm width.The influences of adsorbent dosage,initial pH,acetaminophen concentration,temperature and contact time were investigated.It was determined that the adsorption of acetaminophen occurred on uniform sorption sites in the aerogel,as suggested by the best fit of data to the Langmuir isotherm,yielding a maximum adsorption capacity of 252.87 mg/g.This highest adsorption performance of the 3D MnO_(2)/rGO aerogel was attained at a dosage of 0.6 g/L,initial pH of 6.2 and temperature of 40℃.The process kinetics were in-line with the pseudo-first-order and pseudo-second-order kinetics at 10 and 20–500 mg/L concentrations,respectively.Thermodynamic assay showed the spontaneity and endothermicity features of the 3D MnO_(2)/rGO-acetaminophen system.The acetaminophen adsorption mechanisms were mainly hydrogen bonding and pore entrapment.Moreover,the as-synthesised aerogel was effectively regenerated using acetone and re-utilised in four adsorption-desorption cycles.Overall,the results highly recommend the implementation of the 3D MnO_(2)/rGO hybrid aerogel for purification of wastewater polluted by acetaminophen residue.展开更多
基金support provided by the Ministry of Higher Education(MOHE)Malaysia under the Fundamental Research Grant Scheme(FRGS/1/2015/SG06/UNIM/02/1)
文摘The remediation of wastewater requires treatment technologies which are robust, efficient,simple to operate and affordable such as adsorption. Lately, three-dimensional(3D)graphene based materials have attracted significant attention as effective adsorbents for wastewater treatment. The intrinsic properties of 3D graphene structure such as large surface area and interconnected porous structure can facilitate the transport of pollutants into the 3D network and provide abundant active sites for trapping the pollutants. For the synthesis of 3D graphene structure, ice-templating is commonly practiced due to its facile steps, cost effectiveness and high scalability potential. This review covers the icetemplating fabrication technique for 3D graphene based materials and their application as adsorbents in eliminating dyes and heavy metals from aqueous media. The assembly mechanisms of the ice-templating fsynthesis are comprehensively discussed. Further discussion on the fundamental principles, critical process parameters and characteristics of ice-templated 3D graphene structures is also included. A thorough review on the mechanisms for batch adsorption of dyes and heavy metals is presented based on the structures and properties of the 3D graphene materials. The review further evaluates the dynamic adsorption in packed columns and the regeneration of 3D graphene based materials.
基金the Ministry of Higher Education (MOHE) Malaysia for providing the financial support towards this work under the Fundamental Research Grant Scheme (No. FRGS/1/2020/STG05/UNIM/02/2)。
文摘Water contamination by non-steroidal anti-inflammatory drugs,such as acetaminophen,is an emerging ecological concern.In this study,a newthree-dimensionalmanganese dioxideengrafted reduced graphene oxide(3D MnO_(2)/rGO)hybrid aerogel was developed for acetaminophen sequestration.The synthesis involved firstly the self-assembly of GO aerogel,followed by thermal reduction and in-situ MnO_(2) growth by redox-reaction.The aerogel demonstrated interlinked planes with smooth surfaces deposited with MnO_(2) nanospheres and pores of 138.4–235.3μm width.The influences of adsorbent dosage,initial pH,acetaminophen concentration,temperature and contact time were investigated.It was determined that the adsorption of acetaminophen occurred on uniform sorption sites in the aerogel,as suggested by the best fit of data to the Langmuir isotherm,yielding a maximum adsorption capacity of 252.87 mg/g.This highest adsorption performance of the 3D MnO_(2)/rGO aerogel was attained at a dosage of 0.6 g/L,initial pH of 6.2 and temperature of 40℃.The process kinetics were in-line with the pseudo-first-order and pseudo-second-order kinetics at 10 and 20–500 mg/L concentrations,respectively.Thermodynamic assay showed the spontaneity and endothermicity features of the 3D MnO_(2)/rGO-acetaminophen system.The acetaminophen adsorption mechanisms were mainly hydrogen bonding and pore entrapment.Moreover,the as-synthesised aerogel was effectively regenerated using acetone and re-utilised in four adsorption-desorption cycles.Overall,the results highly recommend the implementation of the 3D MnO_(2)/rGO hybrid aerogel for purification of wastewater polluted by acetaminophen residue.
