CTS-g-（AA-co-SS）/ISC hybrid hydrogel adsorbent with crosslinked network structure and superior adsorption performance for rare-earth metal ions was successfully synthesized in aqueous solution by a simple one-step f...CTS-g-（AA-co-SS）/ISC hybrid hydrogel adsorbent with crosslinked network structure and superior adsorption performance for rare-earth metal ions was successfully synthesized in aqueous solution by a simple one-step free-radical grafting polymerization reaction among acrylic acid（AA）, sodium p-styrenesulfonate（SS） and chitosan（CTS） using illite/smectite clay（ISC） as the inorganic additive. The structure of the as-prepared CTS-g-（AA-co-SS）/ISC hydrogel adsorbent was characterized, and the reaction parameters such as AA/SS molar ratio and ISC content were optimized, and the effects of pH values, initial concentration and contact time on the adsorption performance for Ce（Ⅲ） and Gd（Ⅲ） were systematically evaluated. It was found that the maximum adsorption capacities of the hydrogel adsorbent toward Ce（Ⅲ） and Gd（Ⅲ） reached 174.05 and 223.79 mg/g, respectively, and the adsorption quickly achieved equilibrium within 15–20 min. The adsorbed Ce（Ⅲ） and Gd（Ⅲ） could be easily desorbed for recovery, and the used adsorbent was able to be regenerated for reuse. After five adsorption-desorption cycles, the regenerated adsorbent could still retain the adsorption capacities that were close to the initial value. The adsorption process was well described by pseudo-second-order kinetic mode and the Langmuir isotherm model, and the chemical complexation between ions and –COO~–was mainly responsible for the high adsorption capacity. As a whole, the hybrid hydrogel adsorbent was potential to be used for the adsorption and recovery of Ce（Ⅲ） and Gd（Ⅲ） from water.展开更多
A series of novel silica-based hybrid adsorbents were prepared by the crosslinking reaction of N-[3- （trimethoxysilyl）propyl] ethylene diamine （TMSPEDA） with epichlorohydrin （ECH） via a sol-gel process. Fourier ...A series of novel silica-based hybrid adsorbents were prepared by the crosslinking reaction of N-[3- （trimethoxysilyl）propyl] ethylene diamine （TMSPEDA） with epichlorohydrin （ECH） via a sol-gel process. Fourier transform infrared （FTIR） spectra confirmed that the reaction occurred. TGA curves showed that the thermal stability of these hybrid adsorbents reached as high as 180 ℃. As a typical example, the adsorption performance of nickel（U） ions onto an adsorbent （the volume ratio of TMSPEDA and ECH was 4：1 ） was explored. It was found that the adsorption of nickel（Ⅱ） ions onto this adsorbent followed the Lagergren pseudo-second-order kinetic model. The investigation of the adsorption mechanism demonstrated that nickel（Ⅱ） adsorption was chiefly controlled by diffusion-chemisorption, suggesting that more diffusion processes were involved in the adsorption of nickel（Ⅱ） ions onto this type of adsorbents. Desorption experiment indicates that these hybrid adsorbents can be regenerated. These findings reveal that this type of silica-based hybrid adsorbent is promising in the separation and recovery of nickel（Ⅱ） ions from Ni-containing wastewater or contaminated water.展开更多
Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the...Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the adsorption behavior of 2-naphthalenesulfonic acid(NSA), sulfuric acid and sulfurous acid from their solution at 298 K onto the novel hybrid iron impregnated D301(Fe-D301). Adsorption affinity of NSA on Fe-D301 was found to be much higher than that of sulfuric acid, while adsorption affinity of sulfuric acid was slightly higher than that of sulfurous acid. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The non-ideal competitive adsorbed model coupled with the single-solute adsorption models were used to predict the bisolute and trinary-solute competitive adsorption equilibria. The NICM coupled with the Langmuir model yields the favorable representation of the bisolute and trinary-solute competitive adsorption behavior.展开更多
Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the...Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the ethanol（EtO H）-mediated As（Ⅲ） adsorption onto Zn-loaded pinecone（PC） biochar through batch experiments conducted under Box–Behnken design. The effect of EtO H on As（Ⅲ） adsorption mechanism was quantitatively elucidated by fitting the experimental data using artificial neural network and quadratic modeling approaches. The quadratic model could describe the limiting nature of EtO H and pH on As（Ⅲ） adsorption,whereas neural network revealed the stronger influence of Et OH（64.5%） followed by pH（20.75%）and As（Ⅲ） concentration（14.75%） on the adsorption phenomena. Besides, the interaction among process variables indicated that Et OH enhances As（Ⅲ） adsorption over a pH range of2 to 7, possibly due to facilitation of ligand–metal（Zn） binding complexation mechanism.Eventually, hybrid response surface model–genetic algorithm（RSM–GA） approach predicted a better optimal solution than RSM, i.e., the adsorptive removal of As（Ⅲ）（10.47 μg/g） is facilitated at 30.22 mg C/L of Et OH with initial As（Ⅲ） concentration of 196.77 μg/L at pH 5.8. The implication of this investigation might help in understanding the application of biochar for removal of various As（Ⅲ） species in the presence of OM.展开更多
By changing the solvents, three polyoxometalate（POM）-based supramolecular hybrids, [Co2 L3][SiW（12）O（40）]·17 H2 O（1）,[Co2 L2（H2 O）4][SiW（12）O（40）].2 EtOH·2 H2 O（2） and [Co2 L3][SiW（12）O（40...By changing the solvents, three polyoxometalate（POM）-based supramolecular hybrids, [Co2 L3][SiW（12）O（40）]·17 H2 O（1）,[Co2 L2（H2 O）4][SiW（12）O（40）].2 EtOH·2 H2 O（2） and [Co2 L3][SiW（12）O（40）]·9 DMA·6 H2 O（3）, have been synthesized under hydrothermal or solvothermal conditions. All three hybrids show various supramolecular structures, which contain two kinds of different metal-organic motifs. A kind of metal-organic cationic cage [Co2 L3]^4＋ is formed in the presence of H2 O for 1, DMA/H2 O for 3, and a metalorganic cationic circle [Co2 L2]^（4＋） is constructed in the presence of EtOH/H2 O for 2. That is to say, the solvents show a key role in tuning the architectures of metal-organic fragments and the final POM-based supramolecular structures. The adsorption properties of 1-3 for different organic dyes have also been investigated.展开更多
A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the s...A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the ssDNA is easy to bind to AuNPs due to its exposed bases which could prevent saltinduced aggregation of AuNPs.The dsDNA always present negative charge because its negatively charged phosphate backbone is exposed.In this case,the dsDNA could disturb the adsorption between dsDNA and AuNPs and result in non-aggregation of AuNPs.After hybridization,chloroauric acid and ascorbic acid were added to the mixture solution,and the solution changed to red immediately and turned to purple in10 min in the present of target DNA.TEM results confirmed that the change of color stemed from aggregation of AuNPs.In order to obtain accurate results by naked eye,the DNA detection assay should be conducted under pH 7.0.展开更多
Photoactive aluminum doped ZnO(AlZnO)was synthesized by sol-gel method.After that,AlZnO photocatalyst was deposited on five carbon-based materials(CBMs)using ultrasonic route followed by solid-state mixing using ball ...Photoactive aluminum doped ZnO(AlZnO)was synthesized by sol-gel method.After that,AlZnO photocatalyst was deposited on five carbon-based materials(CBMs)using ultrasonic route followed by solid-state mixing using ball mill.The CBMs used were poly aniline(PANI),carbon nitride(CN),carbon nanotubes(CNT),graphene(G),and carbon nanofibers(CNF).The crystal phases,elemental compositions,morphological,and optical properties of the AlZnO@CBMs composites were investigated.Experimental results revealed that two of AlZnO@CBMs composites exhibited superior bleaching efficiency(100%removal)and photocatalytic stability(three cycles)for 50μmol/L Methylene Blue(MB)contaminated water after 60 min irradiation in visible light at pH 6.5,0.7%H2O2,and 5 g/L inorganic salts.Under optimum conditions,AlZnO@CBMs nanocomposites were employed for the treatment of mixed dyestuffs composed of MB,Methyl Orange(MO),Astrazone Blue FRR(BB 69),and Rhodamine B(RhB)dyes under dark,ultraviolet,visible,and direct sunlight.For mixed dyestuffs,the AlZnO@G achieved the highest dye sorption capacity(60.91μmol dye stuffs/g)with kinetic rate 8.22×10^-3 min^-1 in 90 min via multi-layer physisorption(Freundlich isotherm)on graphene sheet.In additions,AlZnO@CN offered the highest photo-kinetic rate(Kphoto)of^54.1×10^-3 min^-1(93.8%after 60 min)under direct sunlight.Furthermore,the selective radical trapping experiment confirmed that the holes and oxidative superoxide radicals are crucial on dyes photodegradation pathway.Owing to their superior performance,AlZnO@G and AlZnO@CN nanocomposites can offer an effective in-situ solar-assisted adsorption/photocatalytic remediation of textile wastewater effluents.展开更多
Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution...Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution.There is a need for green and sustainable solutions to remove air pollutants,as opposed to conventional techniques which can be expensive,consume additional energy and generate further waste.We developed a novel integrated bioreactor combined with recyclable iron oxide nano/micro-particle adsorption interfaces,to remove CO_2,and undesired organic air pollutants using natural particles,while generating oxygen.This semi-continuous bench-scale photo-bioreactor was shown to successfully clean up simulated emission streams of up to 45% CO_2 with a conversion rate of approximately 4%CO_2 per hour,generating a steady supply of oxygen（6 mmol/hr）,while nanoparticles effectively remove several undesired organic by-products.We also showed algal waste of the bioreactor can be used for mercury remediation.We estimated the potential CO_2 emissions that could be captured from our new method for three industrial cases in which,coal,oil and natural gas were used.With a 30% carbon capture system,the reduction of CO_2 was estimated to decrease by about 420,000,320,000 and 240,000 metric tonnes,respectively for a typical 500 MW power plant.The cost analysis we conducted showed potential to scale-up,and the entire system is recyclable and sustainable.We further discuss the implications of usage of this complete system,or as individual units,that could provide a hybrid option to existing industrial setups.展开更多
基金Project supported by the National Natural Science Foundation of China(51403221,21377135,U1407114)the“863”Project of the Chinese Ministry of Science and Technology(2013AA032003)
文摘CTS-g-（AA-co-SS）/ISC hybrid hydrogel adsorbent with crosslinked network structure and superior adsorption performance for rare-earth metal ions was successfully synthesized in aqueous solution by a simple one-step free-radical grafting polymerization reaction among acrylic acid（AA）, sodium p-styrenesulfonate（SS） and chitosan（CTS） using illite/smectite clay（ISC） as the inorganic additive. The structure of the as-prepared CTS-g-（AA-co-SS）/ISC hydrogel adsorbent was characterized, and the reaction parameters such as AA/SS molar ratio and ISC content were optimized, and the effects of pH values, initial concentration and contact time on the adsorption performance for Ce（Ⅲ） and Gd（Ⅲ） were systematically evaluated. It was found that the maximum adsorption capacities of the hydrogel adsorbent toward Ce（Ⅲ） and Gd（Ⅲ） reached 174.05 and 223.79 mg/g, respectively, and the adsorption quickly achieved equilibrium within 15–20 min. The adsorbed Ce（Ⅲ） and Gd（Ⅲ） could be easily desorbed for recovery, and the used adsorbent was able to be regenerated for reuse. After five adsorption-desorption cycles, the regenerated adsorbent could still retain the adsorption capacities that were close to the initial value. The adsorption process was well described by pseudo-second-order kinetic mode and the Langmuir isotherm model, and the chemical complexation between ions and –COO~–was mainly responsible for the high adsorption capacity. As a whole, the hybrid hydrogel adsorbent was potential to be used for the adsorption and recovery of Ce（Ⅲ） and Gd（Ⅲ） from water.
基金Supported by the National Natural Science Foundation of China(21376059)the Key Discipline of Hefei University(2014xk01)
文摘A series of novel silica-based hybrid adsorbents were prepared by the crosslinking reaction of N-[3- （trimethoxysilyl）propyl] ethylene diamine （TMSPEDA） with epichlorohydrin （ECH） via a sol-gel process. Fourier transform infrared （FTIR） spectra confirmed that the reaction occurred. TGA curves showed that the thermal stability of these hybrid adsorbents reached as high as 180 ℃. As a typical example, the adsorption performance of nickel（U） ions onto an adsorbent （the volume ratio of TMSPEDA and ECH was 4：1 ） was explored. It was found that the adsorption of nickel（Ⅱ） ions onto this adsorbent followed the Lagergren pseudo-second-order kinetic model. The investigation of the adsorption mechanism demonstrated that nickel（Ⅱ） adsorption was chiefly controlled by diffusion-chemisorption, suggesting that more diffusion processes were involved in the adsorption of nickel（Ⅱ） ions onto this type of adsorbents. Desorption experiment indicates that these hybrid adsorbents can be regenerated. These findings reveal that this type of silica-based hybrid adsorbent is promising in the separation and recovery of nickel（Ⅱ） ions from Ni-containing wastewater or contaminated water.
基金Supported by the National Natural Science Foundation of China(No.21276027)the Higher Educational Science and Technology Program of Shandong Province,China(No.J14LC05)
文摘Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the adsorption behavior of 2-naphthalenesulfonic acid(NSA), sulfuric acid and sulfurous acid from their solution at 298 K onto the novel hybrid iron impregnated D301(Fe-D301). Adsorption affinity of NSA on Fe-D301 was found to be much higher than that of sulfuric acid, while adsorption affinity of sulfuric acid was slightly higher than that of sulfurous acid. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The non-ideal competitive adsorbed model coupled with the single-solute adsorption models were used to predict the bisolute and trinary-solute competitive adsorption equilibria. The NICM coupled with the Langmuir model yields the favorable representation of the bisolute and trinary-solute competitive adsorption behavior.
基金supported by the research funds from the University of Ulsan in South Korea during the financial year 2012–2013
文摘Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the ethanol（EtO H）-mediated As（Ⅲ） adsorption onto Zn-loaded pinecone（PC） biochar through batch experiments conducted under Box–Behnken design. The effect of EtO H on As（Ⅲ） adsorption mechanism was quantitatively elucidated by fitting the experimental data using artificial neural network and quadratic modeling approaches. The quadratic model could describe the limiting nature of EtO H and pH on As（Ⅲ） adsorption,whereas neural network revealed the stronger influence of Et OH（64.5%） followed by pH（20.75%）and As（Ⅲ） concentration（14.75%） on the adsorption phenomena. Besides, the interaction among process variables indicated that Et OH enhances As（Ⅲ） adsorption over a pH range of2 to 7, possibly due to facilitation of ligand–metal（Zn） binding complexation mechanism.Eventually, hybrid response surface model–genetic algorithm（RSM–GA） approach predicted a better optimal solution than RSM, i.e., the adsorptive removal of As（Ⅲ）（10.47 μg/g） is facilitated at 30.22 mg C/L of Et OH with initial As（Ⅲ） concentration of 196.77 μg/L at pH 5.8. The implication of this investigation might help in understanding the application of biochar for removal of various As（Ⅲ） species in the presence of OM.
基金financially supported by the National Natural Science Foundation of China(Nos. 21671025, 21471021, 21501013,21401010)Program for Distinguished Professor of Liaoning Province(No. 2015399)
文摘By changing the solvents, three polyoxometalate（POM）-based supramolecular hybrids, [Co2 L3][SiW（12）O（40）]·17 H2 O（1）,[Co2 L2（H2 O）4][SiW（12）O（40）].2 EtOH·2 H2 O（2） and [Co2 L3][SiW（12）O（40）]·9 DMA·6 H2 O（3）, have been synthesized under hydrothermal or solvothermal conditions. All three hybrids show various supramolecular structures, which contain two kinds of different metal-organic motifs. A kind of metal-organic cationic cage [Co2 L3]^4＋ is formed in the presence of H2 O for 1, DMA/H2 O for 3, and a metalorganic cationic circle [Co2 L2]^（4＋） is constructed in the presence of EtOH/H2 O for 2. That is to say, the solvents show a key role in tuning the architectures of metal-organic fragments and the final POM-based supramolecular structures. The adsorption properties of 1-3 for different organic dyes have also been investigated.
基金financially supported by the National Key Research and Development Program of China (No.2017YFA0205301)the National Natural Science Foundation of China (Nos.61527806, 81902153 and 61871180)+2 种基金the Natural Science Foundation of Hunan Province (No.2017JJ2069)the Hunan Key Research Project (No.2017SK2174)the Programs for Changjiang Scholars and Innovative Research Team in University (No.IRT_15R13)
文摘A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the ssDNA is easy to bind to AuNPs due to its exposed bases which could prevent saltinduced aggregation of AuNPs.The dsDNA always present negative charge because its negatively charged phosphate backbone is exposed.In this case,the dsDNA could disturb the adsorption between dsDNA and AuNPs and result in non-aggregation of AuNPs.After hybridization,chloroauric acid and ascorbic acid were added to the mixture solution,and the solution changed to red immediately and turned to purple in10 min in the present of target DNA.TEM results confirmed that the change of color stemed from aggregation of AuNPs.In order to obtain accurate results by naked eye,the DNA detection assay should be conducted under pH 7.0.
文摘Photoactive aluminum doped ZnO(AlZnO)was synthesized by sol-gel method.After that,AlZnO photocatalyst was deposited on five carbon-based materials(CBMs)using ultrasonic route followed by solid-state mixing using ball mill.The CBMs used were poly aniline(PANI),carbon nitride(CN),carbon nanotubes(CNT),graphene(G),and carbon nanofibers(CNF).The crystal phases,elemental compositions,morphological,and optical properties of the AlZnO@CBMs composites were investigated.Experimental results revealed that two of AlZnO@CBMs composites exhibited superior bleaching efficiency(100%removal)and photocatalytic stability(three cycles)for 50μmol/L Methylene Blue(MB)contaminated water after 60 min irradiation in visible light at pH 6.5,0.7%H2O2,and 5 g/L inorganic salts.Under optimum conditions,AlZnO@CBMs nanocomposites were employed for the treatment of mixed dyestuffs composed of MB,Methyl Orange(MO),Astrazone Blue FRR(BB 69),and Rhodamine B(RhB)dyes under dark,ultraviolet,visible,and direct sunlight.For mixed dyestuffs,the AlZnO@G achieved the highest dye sorption capacity(60.91μmol dye stuffs/g)with kinetic rate 8.22×10^-3 min^-1 in 90 min via multi-layer physisorption(Freundlich isotherm)on graphene sheet.In additions,AlZnO@CN offered the highest photo-kinetic rate(Kphoto)of^54.1×10^-3 min^-1(93.8%after 60 min)under direct sunlight.Furthermore,the selective radical trapping experiment confirmed that the holes and oxidative superoxide radicals are crucial on dyes photodegradation pathway.Owing to their superior performance,AlZnO@G and AlZnO@CN nanocomposites can offer an effective in-situ solar-assisted adsorption/photocatalytic remediation of textile wastewater effluents.
基金supported by Natural Sciences and Engineering Research Council of Canada(NSERC)-NSERC CREATE Mine of Knowledge,FRQNT(Fonds de recherche du Québec-Nature et Technologies),and Environment Canada
文摘Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution.There is a need for green and sustainable solutions to remove air pollutants,as opposed to conventional techniques which can be expensive,consume additional energy and generate further waste.We developed a novel integrated bioreactor combined with recyclable iron oxide nano/micro-particle adsorption interfaces,to remove CO_2,and undesired organic air pollutants using natural particles,while generating oxygen.This semi-continuous bench-scale photo-bioreactor was shown to successfully clean up simulated emission streams of up to 45% CO_2 with a conversion rate of approximately 4%CO_2 per hour,generating a steady supply of oxygen（6 mmol/hr）,while nanoparticles effectively remove several undesired organic by-products.We also showed algal waste of the bioreactor can be used for mercury remediation.We estimated the potential CO_2 emissions that could be captured from our new method for three industrial cases in which,coal,oil and natural gas were used.With a 30% carbon capture system,the reduction of CO_2 was estimated to decrease by about 420,000,320,000 and 240,000 metric tonnes,respectively for a typical 500 MW power plant.The cost analysis we conducted showed potential to scale-up,and the entire system is recyclable and sustainable.We further discuss the implications of usage of this complete system,or as individual units,that could provide a hybrid option to existing industrial setups.
