As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective...As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.展开更多
The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropr...The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.展开更多
Lignin is a typical biological macromolecule with a three-dimensional network structure and abundant functional groups. It has excellent ionic complexation ability and amphiphilic molecular structure characteristics.I...Lignin is a typical biological macromolecule with a three-dimensional network structure and abundant functional groups. It has excellent ionic complexation ability and amphiphilic molecular structure characteristics.In this study, the carbon steel anticorrosion performance of sodium lignosulfonate(SLS) in an acid solution was evaluated using the weight loss method, electrochemical measurements, scanning vibration electrode technique(SVET), and surface characterization methods. SLS exhibited excellent corrosion inhibition efficiency for Q235carbon steel in 1 mol·L^(-1) HCl, reaching a maximum value of 98%. A low SLS concentration of 20 mg·L^(-1) resulted in the maximum corrosion inhibition efficiency, which remained nearly constant at higher SLS concentrations.The SVET test demonstrated that the formation of an SLS adsorption film can impede corrosion. This study confirms the significance of the application of green biomass resources in the field of metal corrosion protection and green functional materials.展开更多
Layer-by-layer(LbL)assembly technology is a facile method for constructing thin film composite membrane.Herein,a novel nanofiltration(NF)membrane was prepared by LbL assembly of polyethyleneimine(PEI)and sodium lignos...Layer-by-layer(LbL)assembly technology is a facile method for constructing thin film composite membrane.Herein,a novel nanofiltration(NF)membrane was prepared by LbL assembly of polyethyleneimine(PEI)and sodium lignosulfonate(LS)followed by cross-linking.The surface composition,morphology,and property of PEI/LS bilayer were detailedly investigated by FTIR/ATR,XPS,SEM,AFM,and water contact angle test.The PEI/LS bilayer full of amino and hydroxyl groups presents increased roughness and improved hydrophilicity.Moreover,the NF performance of PEI/LS LbL assembly membranes can be modulated by bilayer number,polyelectrolyte concentration,and salt content.The water flux reduced while the salt rejection greatly improved as increasing the bilayer numbers,PEI concentration,or NaCl content.More than 95%MgSO4 and MgCl2,as well as 80%NaCl can be rejected by a NF membrane prepared by 6 PEI/LS bilayers,1 wt%PEI,0.5 wt%LS,and 1 mol/L NaCl.Furthermore,this NF membrane can be used to remove more than 95%heavy metal ions(Cd2+,Zn2+,Mn2+,Cr2+,Cu2+,and Ni2+).This work proposed a promising NF membrane by using PEI/LS as low cost polyelectrolytes and facile LbL assembly method,which should receive much attention in water purification.展开更多
This work uses thermal polymerization of urea nitrate,oxyacetic acid and urea as the raw material to prepare ultra-thin porous carbon nitride with carbon defects and C-O band(OA-UN-CN).Density functional theory(DFT)ca...This work uses thermal polymerization of urea nitrate,oxyacetic acid and urea as the raw material to prepare ultra-thin porous carbon nitride with carbon defects and C-O band(OA-UN-CN).Density functional theory(DFT)calculations showed OA-UN-CN had narrower band gap,faster electron transport and a new internal construction electric field.Additionally,the prepared OA-UN-CN significantly enhanced photocatalytic activation of peroxymonosulfate(PMS)due to enhanced light absorption performance and faster electron overflow.As the result,the OA-UN-CN/PMS could entirely degrade bisphenol A(BPA)within 30 min,where the photodegradation rate was 81.8 and 7.9 times higher than that of g-C_(3)N_(4)and OA-UN-CN,respectively.Beyond,the OA-UN-CN/PMS could likewise degrade other bisphenol pollutants and sodium lignosulfonate efficiently.We suggested possible photocatalytic degradation pathways accordingly and explored the toxicity of its degradation products.This work provides a new idea on the development of advanced photocatalytic oxidation processes for the treatment of bisphenol pollutants and lignin derivatives,via a metal-free photothermal-catalyst.展开更多
基金supported by the National Key Research and Development Program of China(2019YFA0210302)the National Natural Science Foundation of China(21878009).
文摘As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.
基金supported by SDUST Research Fund(Grant No.2018TDJH101)Key Research and Development Project of Shandong(Grant No.2019GGX103035)+2 种基金National Natural Science Foundation of China(Grant Nos.51904174,52074175)Young Science and Technology Innovation Program of Shandong Province(Grant No.2020KJD001)Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team。
文摘The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.
基金financially supported by the National Natural Science Foundation of China (Nos.22278092 and 52001080)the Science and Technology Research Project of Guangzhou(Nos.2023A03J0034, 2023A04J0077 and 202102020467)+3 种基金the R&D Program of Joint Institute of GZHU&ICo ST (No.GI202111)the Platform Research Capability Enhancement Project of Guangzhou University(No.69-620939)Guangzhou University’s 2020 Training Program for Talent (No.69-62091109)the Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou (No.202255464)。
文摘Lignin is a typical biological macromolecule with a three-dimensional network structure and abundant functional groups. It has excellent ionic complexation ability and amphiphilic molecular structure characteristics.In this study, the carbon steel anticorrosion performance of sodium lignosulfonate(SLS) in an acid solution was evaluated using the weight loss method, electrochemical measurements, scanning vibration electrode technique(SVET), and surface characterization methods. SLS exhibited excellent corrosion inhibition efficiency for Q235carbon steel in 1 mol·L^(-1) HCl, reaching a maximum value of 98%. A low SLS concentration of 20 mg·L^(-1) resulted in the maximum corrosion inhibition efficiency, which remained nearly constant at higher SLS concentrations.The SVET test demonstrated that the formation of an SLS adsorption film can impede corrosion. This study confirms the significance of the application of green biomass resources in the field of metal corrosion protection and green functional materials.
基金Zhejiang Provincial Natural Science Foundation of China(No.LY18E030002)Natural Science Foundation of Ningbo(No.2018A610111)K.C.Wong Magna Fund in Ningbo University.
文摘Layer-by-layer(LbL)assembly technology is a facile method for constructing thin film composite membrane.Herein,a novel nanofiltration(NF)membrane was prepared by LbL assembly of polyethyleneimine(PEI)and sodium lignosulfonate(LS)followed by cross-linking.The surface composition,morphology,and property of PEI/LS bilayer were detailedly investigated by FTIR/ATR,XPS,SEM,AFM,and water contact angle test.The PEI/LS bilayer full of amino and hydroxyl groups presents increased roughness and improved hydrophilicity.Moreover,the NF performance of PEI/LS LbL assembly membranes can be modulated by bilayer number,polyelectrolyte concentration,and salt content.The water flux reduced while the salt rejection greatly improved as increasing the bilayer numbers,PEI concentration,or NaCl content.More than 95%MgSO4 and MgCl2,as well as 80%NaCl can be rejected by a NF membrane prepared by 6 PEI/LS bilayers,1 wt%PEI,0.5 wt%LS,and 1 mol/L NaCl.Furthermore,this NF membrane can be used to remove more than 95%heavy metal ions(Cd2+,Zn2+,Mn2+,Cr2+,Cu2+,and Ni2+).This work proposed a promising NF membrane by using PEI/LS as low cost polyelectrolytes and facile LbL assembly method,which should receive much attention in water purification.
基金the National Natural Science Foundation of China(No.22076068,8111310014)(China)the University of Calgary’s Canada First Research Excellence Fund(CFREF)program(Canada)for financial support。
文摘This work uses thermal polymerization of urea nitrate,oxyacetic acid and urea as the raw material to prepare ultra-thin porous carbon nitride with carbon defects and C-O band(OA-UN-CN).Density functional theory(DFT)calculations showed OA-UN-CN had narrower band gap,faster electron transport and a new internal construction electric field.Additionally,the prepared OA-UN-CN significantly enhanced photocatalytic activation of peroxymonosulfate(PMS)due to enhanced light absorption performance and faster electron overflow.As the result,the OA-UN-CN/PMS could entirely degrade bisphenol A(BPA)within 30 min,where the photodegradation rate was 81.8 and 7.9 times higher than that of g-C_(3)N_(4)and OA-UN-CN,respectively.Beyond,the OA-UN-CN/PMS could likewise degrade other bisphenol pollutants and sodium lignosulfonate efficiently.We suggested possible photocatalytic degradation pathways accordingly and explored the toxicity of its degradation products.This work provides a new idea on the development of advanced photocatalytic oxidation processes for the treatment of bisphenol pollutants and lignin derivatives,via a metal-free photothermal-catalyst.
