Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time and ions concentration on adsorption capa...Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time and ions concentration on adsorption capacity were examined. The maximum adsorption capacity of 1689 mg/g was observed at an initial p H value of 3.5 after agitating for 10 min. It was demonstrated that polyvinylpyrrolidone-reduced graphene oxide had a huge adsorption capacity for Cu ions, which was 10 times higher than maximal value reported in previous works. The adsorption mechanism was also discussed by density functional theory. It demonstrates that Cu ions are attracted to surface of reduced graphene oxide by C atoms in reduced graphene oxide modified by polyvinylpyrrolidone through physisorption processes, which may be responsible for the higher adsorption capacity. Our results suggest that polyvinylpyrrolidone-reduced graphene oxide is an effective adsorbent for removing Cu ions in wastewater. It also provides a new way to improve the adsorption capacity of reduced graphene oxide for dealing with the heavy metal ion in wastewater.展开更多
With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied...With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied because of their relatively cheap,high efficiency,and easy handling.In this study,a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate,acrylamide and attapulgite for dye adsorption.Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide).Then alginate-g-poly(acrylamide)was cross-linked by Ca2+ions in present of attapulgite to form composite hydrogel bead.Scanning electron microscopy(SEM)results show that the freeze dried composite hydrogel bead has multilayer flake structure incorporating attapulgite.Fourier transform infrared spectroscopy(FTIR)and Thermo-gravimetric analysis(TGA)results indicate that acrylamide has been successfully grafted polymerization on sodium alginate.Grafting polymerization of acrylamide onto sodium alginate obviously enhances the swelling of hydrogel bead.Incorporating of attapulgite into hydrogel bead effectively enhances the adsorption capacity to methylene blue and the maximum adsorption capacity is 155.7 mg g-1.Multilayer flake structure increases the adsorption area for methylene blue,but hinders the diffusion of methylene blue into the inner of composite hydrogel bead.High pH solution is beneficial to the adsorption.Pseudo-second order model and Fraundlinch model best describe the adsorption kinetic and isotherm,respectively.These results indicate that composite hydrogel bead is a promising adsorption material for dye-contaminated water treatment.展开更多
First-principles calculations based on density functional theory are used to investigate the adsorptions and diffusions of carbon atoms on the surface and in the subsurface of Co （200）. The preferred site for the ca...First-principles calculations based on density functional theory are used to investigate the adsorptions and diffusions of carbon atoms on the surface and in the subsurface of Co （200）. The preferred site for the carbon atom on the surface is the hollow site, and the preferred site in the subsurface is the octahedral site. There is charge transfer from the surface to the adsorbed carbon atom, and for the most favorable adsorbed structure the charge transfer is largest. Moreover, the energy barriers for the diffusions of carbon atoms on the surface and from the surface into the subsurface and then back to the surface are calculated in detail. The results indicate that the energy barrier for the diffusion of carbon atoms on the surface is comparable to that from the subsurface to the surface. The results imply that both the direct surface nucleation and the surface segregation from Co bulk can be observed in the chemical vapor deposition growth of graphene on Co （200） substrate, which can gain a new insight into the growth mechanism of graphene.展开更多
We investigate the adsorptions of Ar on Al （111） and Ir （111） surfaces at the four high symmetry sites, i.e., top, bridge, fcc- and hcp-hollow sites at the coverage of 0.25 monolayer （ML） using the density funct...We investigate the adsorptions of Ar on Al （111） and Ir （111） surfaces at the four high symmetry sites, i.e., top, bridge, fcc- and hcp-hollow sites at the coverage of 0.25 monolayer （ML） using the density functional theory within the generalized gradient approximation of Perdew, Burke and Ernzerhof functions. The geometric structures, the binding energies, the electronic properties of argon atoms adsorbed on Al （111） and Ir （111） surfaces, the difference in electron density between on the Al （111） surface and on the Ir （111） surface and the total density of states are calculated. Our studies indicate that the most stable adsorption site of Ar on the Al （111） surface is found to be the fcc-hollow site for the （2 x 2） structure. The corresponding binding energy of an argon atom at this site is 0.538 eV/Ar atom at a coverage of 0.25 ML. For the Ar adsorption on Ir （111） surface at the same coverage, the most favourable site is the hcp-hollow site, with a corresponding binding energy of 0.493 eV. The total density of states （TDOS） is analysed for Ar adsorption on Al （111） surface and it is concluded that the adsorption behaviour is dominated by the interaction between 3s, 3p orbits of Ar atom and the 3p orbit of the base Al metal and the formation of sp hybrid orbital. For Ar adsorption on Ir （111） surface, the conclusion is that the main interaction in the process of Ar adsorption on Ir （111） surface comes from the 3s and 3p orbits of argon atom and 5d orbit of Ir atom.展开更多
Black Arsenic-phosphorus(AsP)monolayer is a novel two-dimensional nanomaterial with the characteristics of modest direct bandgap and superhigh carrier mobility.However,little is known about how the surface adsorption ...Black Arsenic-phosphorus(AsP)monolayer is a novel two-dimensional nanomaterial with the characteristics of modest direct bandgap and superhigh carrier mobility.However,little is known about how the surface adsorption affects the property of AsP monolayer.Motivated by this,we researched systematically the geometry,adsorption energy,magnetic moment and electronic structure of 11 different adatoms adsorbed on AsP monolayer using firstprinciples calculations.The adatoms used in this study include light nonmetallic(C,N,O)adatoms,period-3 metal(Na,Mg,Al)adatoms,and transition-metal(Ti,V,Cr,Mn,and Fe)adatoms.The adatoms cause an abundant variety of structural,magnetic and electronic properties.This study shows that AsP binds strongly with all adatoms under study and the adsorption energies in all systems are much stronger than that on graphene,Si C,BN,or MoS2.The semiconductor property of AsP is affected by the introduction of adsorbed atoms,which can induce mid-gap states or cause n-type doping.Moreover,the adatom adsorptions cause various spintronic characteristics:N-,Ti-,and Fe-adsorbed AsP become bipolar semiconductors,while the Mn-decorated AsP becomes a bipolar spin-gapless semiconductor.Our results suggest that atomic adsorption on AsP monolayers has potential application in the field of nanoelectronics and spintronics.展开更多
China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components ...China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components on the transportation properties of Cd(II)at the sediment-water interface is essential.In this study,typical DOM from different sources was selected to study Cd(II)mobility at the sediment-water interface.Results showed that terrestrial-derived DOM(fulvic acids,FA)and autochthonous-derived DOM(α-amylase,B1)inhibit Cd(II)sequestration by sediments(42.5%and 5.8%,respectively),while anthropogenic-derived DOM(sodium dodecyl benzene sulfonate,SDBS)increased the Cd(II)adsorption capacity by sediments by 2.8%.Fluorescence quenching coupling with parallel factor analysis(EEM-PARAFAC)was used to characterize different DOM components.The results showed that FA contains three kinds of components(C1,C3:protein-like components,C2:humic-like components);SDBS contains two kinds of components(C1,C2:protein-like components);B1 contains three kinds of components(C1,C2:protein-like components,C3:humic-like components).Three complex reaction modelswere used to characterize the ability of Cd(II)complex with DOM,and it was found that the humic-like component could hardly be complex with Cd(II).Accordingly,humic-like components compete for Cd(II)adsorption sites on the sediment surface and inhibit Cd(II)adsorption fromsediments.Fourier transform infrared spectroscopy(FTIR)of the sediment surface before and after Cd(II)addition was analyzed and proved the competitive adsorption theory.This study provides a better understanding of the Cd(II)mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.展开更多
Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Sev...Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Several collectors were initially selected through micro-flotation tests,leading to the identification of optimal proportions for a four-component collector system(SHA-OHA-SPA-DBIA in a 4:3:2:1 ratio).Molecular dynamics simulations and surface tension tests were used to investigate the micellar behavior of these collectors in aqueous solution.The adsorption characteristics were quantified using microcalorimetry,enabling the determination of collection entropy and changes in Gibbs free energy.The four-component collector system showed the highest entropy change and the most favorable Gibbs free energy,leading to a cassiterite recovery of above 90%at a concentration of 8.0×10^(5)mol/L.Various analytical techniques were employed to systematically characterize the adsorption mechanism.The findings revealed a positive correlation between the adsorption products formed by the multicomponent collectors on the cassiterite surface and the entropy changes.Industrial-scale testing of the high-entropy collector system produced a tin concentrate with an Sn grade of 6.17%and an Sn recovery of 82.43%,demonstrating its substantial potential for practical applications in cassiterite flotation.展开更多
During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this ...During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this study,the impact of chlorination and UV modification on the physicochemical properties of polystyrene(PS)and polyvinyl chloride(PVC)were investigated,and the adsorption behavior of pefloxacin(PEF)before and after modificationwas examined.The effect of pH,ionic strength,dissolved organicmatter,heavymetal ions and other water environmental conditions on adsorption behavior was revealed.The results showed that PS had a higher adsorption capacity of PEF than PVC,and the modification increased the presence of O-containing functional groups in the MPs,thereby enhancing the adsorption capacity of both materials.Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period,leading to better adsorption performance of chlorination.The optimal pH for adsorption was found to be 6,and NaCl,sodium alginate and Cu2+would inhibit adsorption to varying degrees,among which the inhibition caused by pH was the strongest.Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs.The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding.The study clarified the effects of modification on the physicochemical properties of MPs,providing reference for subsequent biotoxicity analysis and environmental protection studies.展开更多
Urbanization and industrialization have escalated water pollution,threatening ecosystems and human health.Water pollution not only degrades water quality but also poses long-term risks to human health through the food...Urbanization and industrialization have escalated water pollution,threatening ecosystems and human health.Water pollution not only degrades water quality but also poses long-term risks to human health through the food chain.The development of efficient wastewater detection and treatment methods is essential for mitigating this environmental hazard.Carbon dots(CDs),as emerging carbon-based nanomaterials,exhibit properties such as biocompatibility,photoluminescence(PL),water solubility,and strong adsorption,positioning them as promising candidates for environmental monitoring and management.Particularly in wastewater treatment,their optical and electron transfer properties make them ideal for pollutant detection and removal.Despite their potential,comprehensive reviews on CDs'role in wastewater treatment are scarce,often lacking detailed insights into their synthesis,PL mechanisms,and practical applications.This review systematically addresses the synthesis,PL mechanisms,and wastewater treatment applications of CDs,aiming to bridge existing research gaps.It begins with an overview of CDs structure and classification,essential for grasping their properties and uses.The paper then explores the pivotal PL mechanisms of CDs,crucial for their sensing capabilities.Next,comprehensive synthesis strategies are presented,encompassing both top-down and bottom-up strategies such as arc discharge,chemical oxidation,and hydrothermal/solvothermal synthesis.The diversity of these methods highlights the potential for tailored CDs production to suit specific environmental applications.Furthermore,the review systematically discusses the applications of CDs in wastewater treatment,including sensing,inorganic removal,and organic degradation.Finally,it delves into the research prospects and challenges of CDs,proposing future directions to enhance their role in wastewater treatment.展开更多
Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreo...Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreover,due to the accumulation of COFs nanoparticles,it is not conducive to the full utilization of their surface functional groups.Currently,the strategy of COFs assembling into aerogel can be a good solution to this problem.Herein,we successfully synthesize composite aerogels(CSR)by in-situ self-assembly of two-dimensional COFs and graphene based on crosslinking of sodium alginate.Sodium alginate in the composite improves the mechanical properties of the aerogel,and graphene provides a template for the in-situ growth of COFs.Impressively,CSR aerogels with different COFs and sizes can be prepared by changing the moiety of the ligand and modulating the addition amount of COFs.The prepared CSR aerogels exhibit porous,low density,good processability and good mechanical properties.Among them,the density of CSR-N-1.6 is only 5 mg/cm3,which is the lowest density among the reported COF aerogels so far.Due to these remarkable properties,CSR aerogels perform excellent adsorption and recycling properties for the efficient and rapid removal of organic pollutants(organic dyes and antibiotics)from polluted water.In addition,it is also possible to visually recognize the presence of antibiotics by fluorescence detection.This work not only provides a new strategy for synthesizing COF aerogels,but also accelerates the practical application of COF aerogels and contributes to environmental remediation.展开更多
The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framewor...The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framework(MOF)Bi-NH_(2)-BDC was prepared and characterized,and the adsorption characteristics of Bi-NH_(2)-BDCwere investigated with typical PPCPs-diclofenac sodium(DCF).It was found that DCF mainly covered the adsorbent surface as a single molecular layer,the adsorption reaction was a spontaneous,entropyincreasing exothermic process and the adsorption mechanisms between Bi-NH_(2)-BDC and DCF were hydrogen bonding,π-πinteractions and electrostatic interactions.In addition,Bi-NH_(2)-BDC also had considerable photocatalytic properties,and its application in adsor-bent desorption treatment effectively solved the problem of secondary pollution,achieving a green and sustainable adsorption desorption cycle.展开更多
This study investigates the adsorption mechanism,the film formation process,and the inhibition performance of benzotriazole(BTAH)on carbon steels with different grain sizes(i.e.,24.5,4.3,and 0.6μm)in 3.5 wt.%NaCl sol...This study investigates the adsorption mechanism,the film formation process,and the inhibition performance of benzotriazole(BTAH)on carbon steels with different grain sizes(i.e.,24.5,4.3,and 0.6μm)in 3.5 wt.%NaCl solution.The results demonstrate that grain refinement significantly impacts the adsorption and inhibition performance of BTAH on carbon steels.Ultra-refinement of steel grains to 0.6μm improves the maximum inhibition efficiency of BTAH to 90.0%within 168 h of immersion,which was much higher than that of the steels with 24.5μm(73.6%)and 4.3μm grain sizes(81.7%).Notably,grain sizes of 4.3 and 0.6μm facilitate a combination of physisorption and chemisorption of BTAH after 120 h of immersion,as evidenced by the X-ray photoelectron spectroscopy(XPS)results and Langmuir adsorption isotherms,while BTAH adsorbed on carbon steels with a grain size of 24.5μm through physisorption during the 168 h of immersion.Ultra-refinement of grains has beneficial impacts on promoting the formation of a stable and dense corrosion inhibitor film,leading to improved corrosion resistance and the mitigation of non-uniform corrosion.These advantageous effects can be attributed to the higher adsorption energy at grain boundaries(approximately-3.12 eV)compared to grain interiors(ranging from-0.79 to 2.47 eV),promoting both the physisorption and chemisorption of organic corrosion inhibitors.The investigation comprehensively illustrates,for the first time,the effects of grain size on the adsorption mechanism,film formation process,and inhibition performance of organic corrosion inhibitors on carbon steels.This study demonstrates a promising approach to enhancing corrosion inhibition performance through microstructural design.展开更多
Current research on heterogeneous advanced oxidation processes(HAOPs)predominantly emphasizes catalyst iteration and innovation.Significant efforts have been made to regulate the electron structure and optimize the el...Current research on heterogeneous advanced oxidation processes(HAOPs)predominantly emphasizes catalyst iteration and innovation.Significant efforts have been made to regulate the electron structure and optimize the electron distribution,thereby increasing the catalytic activity.However,this focus often overshadows an equally essential aspect of HAOPs:the adsorption effect.Adsorption is a critical initiator for triggering the interaction of oxidants and contaminants with heterogeneous catalysts.The efficacy of these interactions is influenced by a variety of physicochemical properties,including surface chemistry and pore sizes,which determine the affinities between contaminants and material surfaces.This dispar ity in affinity is pivotal because it underpins the selective removal of contaminants,especially in complex waste streams containing diverse contaminants and competing matrices.Consequently,understanding and mastering these interfacial interactions is fundamentally indispensable not only for improving pro cess efficiency but also for enhancing the selectivity of contaminant removal.Herein,we highlight the importance of adsorption-driven interfacial interactions for fundamentally elucidating the catalytic mechanisms of HAOPs.Such interactions dictate the overall performance of the treatment processes by balancing the adsorption,reaction,and desorption rates on the catalyst surfaces.Elucidating the adsorption effect not only shifts the paradigm in understanding HAOPs but also improves their practical ity in water treatment and wastewater decontamination.Overall,we propose that revisiting adsorption driven interfacial interactions holds great promise for optimizing catalytic processes to develop effective HAOP strategies.展开更多
Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and hea...Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.展开更多
Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial ...Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.展开更多
A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was eva...A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was evaluated by the mass loss experiment,electrochemical tests and surface analysis.The results show that PT exhibits excellent inhibition performance and the maximum inhibition efficiency of PT reaches 99.6%.The interaction mechanism was investigated through X-ray photoelectron spectroscopy(XPS)and molecule dynamics simulation based on the density functional theory(DFT).The S-Cu,Al-N and Cu-N bonds are formed by the chemical interactions,leading to the adsorption of PT on the NAB surface.The diffusion of corrosive species is hindered considerably by the protective PT film with composition of(PT-Cu)_(ads)and(PT-Al)_(ads)on the PT/NAB interface.The degree of suppression is increased with the addition of more PT molecules.展开更多
The inhibitory properties of rapeseed cake meal extract(RCME)on the corrosion of cold rolled steel(CRS)in trichloroacetic acid(TCA)were systematically investigated using gravimetric,electrochemical,surface characteriz...The inhibitory properties of rapeseed cake meal extract(RCME)on the corrosion of cold rolled steel(CRS)in trichloroacetic acid(TCA)were systematically investigated using gravimetric,electrochemical,surface characterizations and theoretical calculations.The results demonstrate that RCME exhibits excellent inhibitory performance with a maximum inhibition efficiency of 92.7%for 100 mg L−1 RCME at 20℃.The adsorption of RCME obeys Langmuir isotherm at 20 and 30℃,Temkin isotherm at 40℃,and Freundlich isotherm at 50℃.RCME acts as a cathodic inhibitor.The charge transfer resistance is increased with the addition of RCME,while the double-layer capacitance decreases.SEM,AFM,CLSM,XPS,XRD and TOF-SIMS analyses confirm that the active components in RCME adsorb onto the surface of CRS,forming a protective film that effectively inhibits the corrosion of CRS by TCA.Along with the increase in the concentration of RCME,the surface tension of the inhibited solution gradually decreases,while the electrical conductivity increases before stabilizing.HPLC-MS and FTIR analyses reveal rutin,linolenic acid,linoleic acid and adenine are the effective substances in RCME.Quantum chemical(QC)calculations and molecular dynamic(MD)simulations indicate that the active centers of the effective inhibitor molecules are predominantly located on benzene rings,O-or N-containing heterocyclic rings,and functional groups such as C=O and C=C.Additionally,their main chains adsorb onto the Fe(001)surface in an approximately flat manner,involving both chemical and physical adsorption processes.展开更多
Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorpti...Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.展开更多
In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation...In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.展开更多
基金the support by National Natural Science Foundation of China under grants (11202006)University’s Science and technology exploiture of Shangxi Province (20121010)the National Basic Research Program of China (G2010CB832701)
文摘Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time and ions concentration on adsorption capacity were examined. The maximum adsorption capacity of 1689 mg/g was observed at an initial p H value of 3.5 after agitating for 10 min. It was demonstrated that polyvinylpyrrolidone-reduced graphene oxide had a huge adsorption capacity for Cu ions, which was 10 times higher than maximal value reported in previous works. The adsorption mechanism was also discussed by density functional theory. It demonstrates that Cu ions are attracted to surface of reduced graphene oxide by C atoms in reduced graphene oxide modified by polyvinylpyrrolidone through physisorption processes, which may be responsible for the higher adsorption capacity. Our results suggest that polyvinylpyrrolidone-reduced graphene oxide is an effective adsorbent for removing Cu ions in wastewater. It also provides a new way to improve the adsorption capacity of reduced graphene oxide for dealing with the heavy metal ion in wastewater.
基金for Doctors of Jinling Institute of Technology(Grant No.jit-b-201415)the Natural Science Foundation for Colleges and Universities of Jiangsu Province(Grant No.12KJD150006)for the financial support of this research.
文摘With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied because of their relatively cheap,high efficiency,and easy handling.In this study,a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate,acrylamide and attapulgite for dye adsorption.Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide).Then alginate-g-poly(acrylamide)was cross-linked by Ca2+ions in present of attapulgite to form composite hydrogel bead.Scanning electron microscopy(SEM)results show that the freeze dried composite hydrogel bead has multilayer flake structure incorporating attapulgite.Fourier transform infrared spectroscopy(FTIR)and Thermo-gravimetric analysis(TGA)results indicate that acrylamide has been successfully grafted polymerization on sodium alginate.Grafting polymerization of acrylamide onto sodium alginate obviously enhances the swelling of hydrogel bead.Incorporating of attapulgite into hydrogel bead effectively enhances the adsorption capacity to methylene blue and the maximum adsorption capacity is 155.7 mg g-1.Multilayer flake structure increases the adsorption area for methylene blue,but hinders the diffusion of methylene blue into the inner of composite hydrogel bead.High pH solution is beneficial to the adsorption.Pseudo-second order model and Fraundlinch model best describe the adsorption kinetic and isotherm,respectively.These results indicate that composite hydrogel bead is a promising adsorption material for dye-contaminated water treatment.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51002014,51202017,and 51372095)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120061120039)+2 种基金the Funds from the Science and Technology Department of Jilin Province,China(Grant Nos.20120745 and 20130101029JC)the Funds from the Department of Education of Jilin Province,China(Grant No.2013279)the Youth Science Research Foundation of Liaoning University,China(Grant No.2013LDQN20)
文摘First-principles calculations based on density functional theory are used to investigate the adsorptions and diffusions of carbon atoms on the surface and in the subsurface of Co （200）. The preferred site for the carbon atom on the surface is the hollow site, and the preferred site in the subsurface is the octahedral site. There is charge transfer from the surface to the adsorbed carbon atom, and for the most favorable adsorbed structure the charge transfer is largest. Moreover, the energy barriers for the diffusions of carbon atoms on the surface and from the surface into the subsurface and then back to the surface are calculated in detail. The results indicate that the energy barrier for the diffusion of carbon atoms on the surface is comparable to that from the subsurface to the surface. The results imply that both the direct surface nucleation and the surface segregation from Co bulk can be observed in the chemical vapor deposition growth of graphene on Co （200） substrate, which can gain a new insight into the growth mechanism of graphene.
基金supported by the National Natural Science Foundation of China (Grant No.11074176 and 10976019)the Doctoral Program of Higher Education of China (Grant No.20100181110080)
文摘We investigate the adsorptions of Ar on Al （111） and Ir （111） surfaces at the four high symmetry sites, i.e., top, bridge, fcc- and hcp-hollow sites at the coverage of 0.25 monolayer （ML） using the density functional theory within the generalized gradient approximation of Perdew, Burke and Ernzerhof functions. The geometric structures, the binding energies, the electronic properties of argon atoms adsorbed on Al （111） and Ir （111） surfaces, the difference in electron density between on the Al （111） surface and on the Ir （111） surface and the total density of states are calculated. Our studies indicate that the most stable adsorption site of Ar on the Al （111） surface is found to be the fcc-hollow site for the （2 x 2） structure. The corresponding binding energy of an argon atom at this site is 0.538 eV/Ar atom at a coverage of 0.25 ML. For the Ar adsorption on Ir （111） surface at the same coverage, the most favourable site is the hcp-hollow site, with a corresponding binding energy of 0.493 eV. The total density of states （TDOS） is analysed for Ar adsorption on Al （111） surface and it is concluded that the adsorption behaviour is dominated by the interaction between 3s, 3p orbits of Ar atom and the 3p orbit of the base Al metal and the formation of sp hybrid orbital. For Ar adsorption on Ir （111） surface, the conclusion is that the main interaction in the process of Ar adsorption on Ir （111） surface comes from the 3s and 3p orbits of argon atom and 5d orbit of Ir atom.
基金supported by the National Natural Science Foundation of China(No.11404268 and No.11774294)the Sichuan Province Applied Science and Technology Project(No.2017JY0056)the R&D Program for International ST Cooperation and Exchanges of Sichuan province(No.2018HH0088)。
文摘Black Arsenic-phosphorus(AsP)monolayer is a novel two-dimensional nanomaterial with the characteristics of modest direct bandgap and superhigh carrier mobility.However,little is known about how the surface adsorption affects the property of AsP monolayer.Motivated by this,we researched systematically the geometry,adsorption energy,magnetic moment and electronic structure of 11 different adatoms adsorbed on AsP monolayer using firstprinciples calculations.The adatoms used in this study include light nonmetallic(C,N,O)adatoms,period-3 metal(Na,Mg,Al)adatoms,and transition-metal(Ti,V,Cr,Mn,and Fe)adatoms.The adatoms cause an abundant variety of structural,magnetic and electronic properties.This study shows that AsP binds strongly with all adatoms under study and the adsorption energies in all systems are much stronger than that on graphene,Si C,BN,or MoS2.The semiconductor property of AsP is affected by the introduction of adsorbed atoms,which can induce mid-gap states or cause n-type doping.Moreover,the adatom adsorptions cause various spintronic characteristics:N-,Ti-,and Fe-adsorbed AsP become bipolar semiconductors,while the Mn-decorated AsP becomes a bipolar spin-gapless semiconductor.Our results suggest that atomic adsorption on AsP monolayers has potential application in the field of nanoelectronics and spintronics.
基金supported by the National Natural Science Foundation of China(Nos.42307524,and 51879103).
文摘China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components on the transportation properties of Cd(II)at the sediment-water interface is essential.In this study,typical DOM from different sources was selected to study Cd(II)mobility at the sediment-water interface.Results showed that terrestrial-derived DOM(fulvic acids,FA)and autochthonous-derived DOM(α-amylase,B1)inhibit Cd(II)sequestration by sediments(42.5%and 5.8%,respectively),while anthropogenic-derived DOM(sodium dodecyl benzene sulfonate,SDBS)increased the Cd(II)adsorption capacity by sediments by 2.8%.Fluorescence quenching coupling with parallel factor analysis(EEM-PARAFAC)was used to characterize different DOM components.The results showed that FA contains three kinds of components(C1,C3:protein-like components,C2:humic-like components);SDBS contains two kinds of components(C1,C2:protein-like components);B1 contains three kinds of components(C1,C2:protein-like components,C3:humic-like components).Three complex reaction modelswere used to characterize the ability of Cd(II)complex with DOM,and it was found that the humic-like component could hardly be complex with Cd(II).Accordingly,humic-like components compete for Cd(II)adsorption sites on the sediment surface and inhibit Cd(II)adsorption fromsediments.Fourier transform infrared spectroscopy(FTIR)of the sediment surface before and after Cd(II)addition was analyzed and proved the competitive adsorption theory.This study provides a better understanding of the Cd(II)mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.
基金supported by Yunnan Science and Technology Leading Talent Project(No.202305AB350005)。
文摘Tin is a critical metal for various industries,making its recovery from low-grade cassiterite ores crucial.This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems.Several collectors were initially selected through micro-flotation tests,leading to the identification of optimal proportions for a four-component collector system(SHA-OHA-SPA-DBIA in a 4:3:2:1 ratio).Molecular dynamics simulations and surface tension tests were used to investigate the micellar behavior of these collectors in aqueous solution.The adsorption characteristics were quantified using microcalorimetry,enabling the determination of collection entropy and changes in Gibbs free energy.The four-component collector system showed the highest entropy change and the most favorable Gibbs free energy,leading to a cassiterite recovery of above 90%at a concentration of 8.0×10^(5)mol/L.Various analytical techniques were employed to systematically characterize the adsorption mechanism.The findings revealed a positive correlation between the adsorption products formed by the multicomponent collectors on the cassiterite surface and the entropy changes.Industrial-scale testing of the high-entropy collector system produced a tin concentrate with an Sn grade of 6.17%and an Sn recovery of 82.43%,demonstrating its substantial potential for practical applications in cassiterite flotation.
基金supported by the Shanxi Scholarship Council of China(No.2023-054)the Applied Basic Research Project of Shanxi Province,China(No.20210302123121)the National Natural Science Foundation of China(No.52170045).
文摘During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this study,the impact of chlorination and UV modification on the physicochemical properties of polystyrene(PS)and polyvinyl chloride(PVC)were investigated,and the adsorption behavior of pefloxacin(PEF)before and after modificationwas examined.The effect of pH,ionic strength,dissolved organicmatter,heavymetal ions and other water environmental conditions on adsorption behavior was revealed.The results showed that PS had a higher adsorption capacity of PEF than PVC,and the modification increased the presence of O-containing functional groups in the MPs,thereby enhancing the adsorption capacity of both materials.Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period,leading to better adsorption performance of chlorination.The optimal pH for adsorption was found to be 6,and NaCl,sodium alginate and Cu2+would inhibit adsorption to varying degrees,among which the inhibition caused by pH was the strongest.Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs.The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding.The study clarified the effects of modification on the physicochemical properties of MPs,providing reference for subsequent biotoxicity analysis and environmental protection studies.
基金supported by the Natural Science Foundation of Hebei Province(No.E2022208046)National Science Foundation of China(No.52004080)+2 种基金Key project of National Natural Science Foundation of China(No.U20A20130)Key research and development project of Hebei Province(No.22373704D)2023 Central Government Guide Local Science and Technology Development Fund Project(No.236Z1812 G)。
文摘Urbanization and industrialization have escalated water pollution,threatening ecosystems and human health.Water pollution not only degrades water quality but also poses long-term risks to human health through the food chain.The development of efficient wastewater detection and treatment methods is essential for mitigating this environmental hazard.Carbon dots(CDs),as emerging carbon-based nanomaterials,exhibit properties such as biocompatibility,photoluminescence(PL),water solubility,and strong adsorption,positioning them as promising candidates for environmental monitoring and management.Particularly in wastewater treatment,their optical and electron transfer properties make them ideal for pollutant detection and removal.Despite their potential,comprehensive reviews on CDs'role in wastewater treatment are scarce,often lacking detailed insights into their synthesis,PL mechanisms,and practical applications.This review systematically addresses the synthesis,PL mechanisms,and wastewater treatment applications of CDs,aiming to bridge existing research gaps.It begins with an overview of CDs structure and classification,essential for grasping their properties and uses.The paper then explores the pivotal PL mechanisms of CDs,crucial for their sensing capabilities.Next,comprehensive synthesis strategies are presented,encompassing both top-down and bottom-up strategies such as arc discharge,chemical oxidation,and hydrothermal/solvothermal synthesis.The diversity of these methods highlights the potential for tailored CDs production to suit specific environmental applications.Furthermore,the review systematically discusses the applications of CDs in wastewater treatment,including sensing,inorganic removal,and organic degradation.Finally,it delves into the research prospects and challenges of CDs,proposing future directions to enhance their role in wastewater treatment.
基金the financial support provided by the National Natural Science Foundation of China(Nos.22175094,21971113)。
文摘Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreover,due to the accumulation of COFs nanoparticles,it is not conducive to the full utilization of their surface functional groups.Currently,the strategy of COFs assembling into aerogel can be a good solution to this problem.Herein,we successfully synthesize composite aerogels(CSR)by in-situ self-assembly of two-dimensional COFs and graphene based on crosslinking of sodium alginate.Sodium alginate in the composite improves the mechanical properties of the aerogel,and graphene provides a template for the in-situ growth of COFs.Impressively,CSR aerogels with different COFs and sizes can be prepared by changing the moiety of the ligand and modulating the addition amount of COFs.The prepared CSR aerogels exhibit porous,low density,good processability and good mechanical properties.Among them,the density of CSR-N-1.6 is only 5 mg/cm3,which is the lowest density among the reported COF aerogels so far.Due to these remarkable properties,CSR aerogels perform excellent adsorption and recycling properties for the efficient and rapid removal of organic pollutants(organic dyes and antibiotics)from polluted water.In addition,it is also possible to visually recognize the presence of antibiotics by fluorescence detection.This work not only provides a new strategy for synthesizing COF aerogels,but also accelerates the practical application of COF aerogels and contributes to environmental remediation.
基金supported by Liaoning Revitalization Talents Program(No.XLYC1907173)the Science and Technology General Project of Liaoning Provincial Education Department(No.LJKMZ20221835)the National Natural Science Foundation of China(Nos.22006073 and 22205027).
文摘The mass production and widespread use of Pharmaceuticals and Personal Care Products(PPCPs)have posed a serious threat to the water environment and public health.In this work,a green metal-based Metal Organic Framework(MOF)Bi-NH_(2)-BDC was prepared and characterized,and the adsorption characteristics of Bi-NH_(2)-BDCwere investigated with typical PPCPs-diclofenac sodium(DCF).It was found that DCF mainly covered the adsorbent surface as a single molecular layer,the adsorption reaction was a spontaneous,entropyincreasing exothermic process and the adsorption mechanisms between Bi-NH_(2)-BDC and DCF were hydrogen bonding,π-πinteractions and electrostatic interactions.In addition,Bi-NH_(2)-BDC also had considerable photocatalytic properties,and its application in adsor-bent desorption treatment effectively solved the problem of secondary pollution,achieving a green and sustainable adsorption desorption cycle.
基金support of the National Natural Science Foundation of China(Nos.52171063,52274362,and 52371049)the Key R&D projects of Henan Province(No.221111230800)+1 种基金the Doctoral Fund of Henan University of Technology(No.2023BS047)the Natural science Project of Zhengzhou Science and Technology Bureau(No.22ZZRDZX04)。
文摘This study investigates the adsorption mechanism,the film formation process,and the inhibition performance of benzotriazole(BTAH)on carbon steels with different grain sizes(i.e.,24.5,4.3,and 0.6μm)in 3.5 wt.%NaCl solution.The results demonstrate that grain refinement significantly impacts the adsorption and inhibition performance of BTAH on carbon steels.Ultra-refinement of steel grains to 0.6μm improves the maximum inhibition efficiency of BTAH to 90.0%within 168 h of immersion,which was much higher than that of the steels with 24.5μm(73.6%)and 4.3μm grain sizes(81.7%).Notably,grain sizes of 4.3 and 0.6μm facilitate a combination of physisorption and chemisorption of BTAH after 120 h of immersion,as evidenced by the X-ray photoelectron spectroscopy(XPS)results and Langmuir adsorption isotherms,while BTAH adsorbed on carbon steels with a grain size of 24.5μm through physisorption during the 168 h of immersion.Ultra-refinement of grains has beneficial impacts on promoting the formation of a stable and dense corrosion inhibitor film,leading to improved corrosion resistance and the mitigation of non-uniform corrosion.These advantageous effects can be attributed to the higher adsorption energy at grain boundaries(approximately-3.12 eV)compared to grain interiors(ranging from-0.79 to 2.47 eV),promoting both the physisorption and chemisorption of organic corrosion inhibitors.The investigation comprehensively illustrates,for the first time,the effects of grain size on the adsorption mechanism,film formation process,and inhibition performance of organic corrosion inhibitors on carbon steels.This study demonstrates a promising approach to enhancing corrosion inhibition performance through microstructural design.
基金supported by the National Key Research and Development Program of China(2022YFC3205300)the National Natural Science Foundation of China(22176124).
文摘Current research on heterogeneous advanced oxidation processes(HAOPs)predominantly emphasizes catalyst iteration and innovation.Significant efforts have been made to regulate the electron structure and optimize the electron distribution,thereby increasing the catalytic activity.However,this focus often overshadows an equally essential aspect of HAOPs:the adsorption effect.Adsorption is a critical initiator for triggering the interaction of oxidants and contaminants with heterogeneous catalysts.The efficacy of these interactions is influenced by a variety of physicochemical properties,including surface chemistry and pore sizes,which determine the affinities between contaminants and material surfaces.This dispar ity in affinity is pivotal because it underpins the selective removal of contaminants,especially in complex waste streams containing diverse contaminants and competing matrices.Consequently,understanding and mastering these interfacial interactions is fundamentally indispensable not only for improving pro cess efficiency but also for enhancing the selectivity of contaminant removal.Herein,we highlight the importance of adsorption-driven interfacial interactions for fundamentally elucidating the catalytic mechanisms of HAOPs.Such interactions dictate the overall performance of the treatment processes by balancing the adsorption,reaction,and desorption rates on the catalyst surfaces.Elucidating the adsorption effect not only shifts the paradigm in understanding HAOPs but also improves their practical ity in water treatment and wastewater decontamination.Overall,we propose that revisiting adsorption driven interfacial interactions holds great promise for optimizing catalytic processes to develop effective HAOP strategies.
基金support from the earmarked fund for XJARS(No.XJARS-06)the Bingtuan Science and Technology Program(Nos.2021DB019,2022CB001-01)+1 种基金the National Natural Science Foundation of China(No.42275014)the Guangdong Foundation for Program of Science and Technology Research,China(No.2023B1212060044)。
文摘Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(Nos.2022M3J1A1063917 and 2021M3H4A3A02086681).
文摘Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.
基金supported by the National Natural Science Foundation of China(No.52171069).
文摘A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was evaluated by the mass loss experiment,electrochemical tests and surface analysis.The results show that PT exhibits excellent inhibition performance and the maximum inhibition efficiency of PT reaches 99.6%.The interaction mechanism was investigated through X-ray photoelectron spectroscopy(XPS)and molecule dynamics simulation based on the density functional theory(DFT).The S-Cu,Al-N and Cu-N bonds are formed by the chemical interactions,leading to the adsorption of PT on the NAB surface.The diffusion of corrosive species is hindered considerably by the protective PT film with composition of(PT-Cu)_(ads)and(PT-Al)_(ads)on the PT/NAB interface.The degree of suppression is increased with the addition of more PT molecules.
基金financially supported by the National Natural Science Foundation of China(No.52161016)Joint Key Project of Agricultural Fundamental Research in Yunnan Provinceg(No.202101BD070001-017)+3 种基金Yunnan Provincial Academician Workstation(No.202305AF150009)Yunnan Province Natural Science Key Foundation(No.202201AS070152)Special Project of“Top Young Talents”of Yunnan Ten Thousand Talents Plan(No.51900109)Special Project of"Leading Talents of Industrial Technology"of Yunnan Ten Thousand Talents Plan(No.80201408).
文摘The inhibitory properties of rapeseed cake meal extract(RCME)on the corrosion of cold rolled steel(CRS)in trichloroacetic acid(TCA)were systematically investigated using gravimetric,electrochemical,surface characterizations and theoretical calculations.The results demonstrate that RCME exhibits excellent inhibitory performance with a maximum inhibition efficiency of 92.7%for 100 mg L−1 RCME at 20℃.The adsorption of RCME obeys Langmuir isotherm at 20 and 30℃,Temkin isotherm at 40℃,and Freundlich isotherm at 50℃.RCME acts as a cathodic inhibitor.The charge transfer resistance is increased with the addition of RCME,while the double-layer capacitance decreases.SEM,AFM,CLSM,XPS,XRD and TOF-SIMS analyses confirm that the active components in RCME adsorb onto the surface of CRS,forming a protective film that effectively inhibits the corrosion of CRS by TCA.Along with the increase in the concentration of RCME,the surface tension of the inhibited solution gradually decreases,while the electrical conductivity increases before stabilizing.HPLC-MS and FTIR analyses reveal rutin,linolenic acid,linoleic acid and adenine are the effective substances in RCME.Quantum chemical(QC)calculations and molecular dynamic(MD)simulations indicate that the active centers of the effective inhibitor molecules are predominantly located on benzene rings,O-or N-containing heterocyclic rings,and functional groups such as C=O and C=C.Additionally,their main chains adsorb onto the Fe(001)surface in an approximately flat manner,involving both chemical and physical adsorption processes.
基金Project supported by Rumah Program 2023 and Net Zero Emission Program(1507/Ⅱ.7/HK.01.00/6/2023)a research facility from the National Research and Innovation Agency of Republic of Indonesia。
文摘Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.
基金Project supported by the Natural Science Foundation Innovation Group Project of Hubei Province(2023AFA044)the National Natural Science Foundation of China(52222405)+1 种基金the Science and Technology Research Project of Education Department of Hubei Province(Q20221505)the China Postdoctoral Science(2023M731041)。
文摘In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.
