High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(M...High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.展开更多
Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical...Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical reaction of CaC_(2) and a carbonate(CaCO_(3),Na2CO_(3),or NaHCO_(3))at ambient temperature.The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2 g^(-1)),highly crosslinked texture,and rich alkynyl and oxygenated groups.The OACMs exhibit excellent Hg(Ⅱ)adsorption due to the soft acid-soft base interaction between alkynyl and Hg(Ⅱ),and OACM-3 derived from CaC_(2) and NaHCO_(3) has the saturated Hg(Ⅱ)adsorbance of 483.9 mg g^(-1)along with good selectivity and recyclability.The adsorption is mainly chemisorption following the Langmuir mode.OACM-3 also shows high adsorbance for other heavy metal ions,e.g.256.6 mg g^(-1)for Pb(II),232.4 mg g^(-1)for Zn(II),and 198.7 mg g^(-1)for Cu(II).This work expands the mechnochemical reaction of CaC_(2)with carbonates and possibly other oxyanionic salts,provides a new synthesis approach for functional alkynyl carbon materials with excellent adsorption performance for heavy metal ions,as well as a feasible approach for CO2 resource utilization.展开更多
The adsorption and desorption of Cu（Ⅱ） and Pb（Ⅱ） on upland red soil,and paddy soils which were originated from the upland soil and cultivated for 8,15,35 and 85 years,were investigated using the batch method.The...The adsorption and desorption of Cu（Ⅱ） and Pb（Ⅱ） on upland red soil,and paddy soils which were originated from the upland soil and cultivated for 8,15,35 and 85 years,were investigated using the batch method.The study showed that the organic matter content and cation exchange capacity （CEC） of the soils are important factors controlling the adsorption and desorption of Cu（Ⅱ） and Pb（Ⅱ）.The 15-Year paddy soil had the highest adsorption capacity for Pb（Ⅱ）,followed by the 35-Year paddy soil.Both the 35-Year paddy soil and 15-Year paddy soil adsorbed more Cu（Ⅱ） than the upland soil and other paddy soils.The 15-Year paddy soils exhibited the highest desorption percentage for both Cu（Ⅱ） and Pb（Ⅱ）.These results are consistent with the trend for the CEC of the soils tested.The high soil CEC contributes not only to the adsorption of Cu（Ⅱ） and Pb（Ⅱ） but also to the electrostatic adsorption of the two heavy metals by the soils.Lower desorption percentages for Cu（Ⅱ） （36.7% to 42.2%） and Pb（Ⅱ） （50.4% to 57.9%） were observed for the 85-Year paddy soil.The highest content of organic matter in the soil was responsible for the low desorption percentages for the two metals because the formation of the complexes between the organic matter and the metals could increase the stability of the heavy metals in the soils.展开更多
The adsorption of Cu（Ⅱ） from aqueous solution onto humic acid （HA） which was isolated from cattle manure （CHA）, peat （PHA）, and leaf litter （LHA） as a function of contact time, pH, ion strength, and initial...The adsorption of Cu（Ⅱ） from aqueous solution onto humic acid （HA） which was isolated from cattle manure （CHA）, peat （PHA）, and leaf litter （LHA） as a function of contact time, pH, ion strength, and initial concentration was studied using the batch method. X-ray absorption spectroscopy （XAS） was used to examine the coordination environment of the Cu（ll） adsorbed by HA at a molecular level. Moreover, the chemical compositions of the isolated HA were characterized by elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy （NMR）. The kinetic data showed that the adsorption equilibrium can be achieved within 8 h. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms could be well fitted by the Langmuir model, and the maximum adsorption capacities of Cu（ll） on CHA, PHA, and LHA were 229.4,210.4, and 197.7 mg g-1, respectively. The adsorption of Cu（Ⅱ） on HA increased with the increase in pH from 2 to 7, and maintained a high level at pH〉7. The adsorption of Cu（Ⅱ） was also strongly influenced by the low ionic strength of 0.01 to 0.2 mol L-1 NaNO3, but was weakly influenced by high ionic strength of 0.4 to 1 mol L-1 NaNO3. The Cu（Ⅱ） adsorption on HA may be mainly attributed to ion exchange and surface complexation. XAS results revealed that the binding site and oxidation state of Cu adsorbed on HA surface did not change at the initial Cu（Ⅱ） concentrations of 15 to 40 mg L 1. For all the Cu（Ⅱ） adsorption samples, each Cu atom was surrounded by 40/N atoms at a bond distance of 1.95 A in the first coordination shell. The presence of the higher Cu coordination shells proved that Cu（Ⅱ） was adsorbed via an inner-sphere covalent bond onto the HA surface. Among the three HA samples, the adsorption capacity and affinity of CHA for Cu（Ⅱ） was the greatest, followed by that of PHA and LHA. All the three HA samples exhibited similar types of elemental and functional groups, but different contents of elemental and functional groups. CHA contained larger proportions of methoxyl C, phenolic C and carbonyl C, and smaller proportions of alkyl C and carbohydrate C than PHA and LHA. The structural differences of the three HA samples are responsible for their distinct adsorption capacity and affinity toward Cu（Ⅱ）. These results are important to achieve better understanding of the behavior of Cu（Ⅱ） in soil and water bodies in the presence of organic materials.展开更多
Cross-linked chitosan(CS),cross-linked chitosan/graphene(CS/RGO10) and cross-linked chitosan/graphene oxide(CS/GO10) were prepared as adsorbents for Cu(Ⅱ).The effects of pH,contact time,adsorbent dosage and initial c...Cross-linked chitosan(CS),cross-linked chitosan/graphene(CS/RGO10) and cross-linked chitosan/graphene oxide(CS/GO10) were prepared as adsorbents for Cu(Ⅱ).The effects of pH,contact time,adsorbent dosage and initial concentration of Cu(Ⅱ) on the adsorbing abilities of CS,CS/RGO10 and CS/GO10 to Cu(Ⅱ) were investigated.The results demonstrate that the adsorption capacities of CS/GO10 and CS/RGO10 are greater than that of CS,especially at pH 5.0 and the adsorption capacities are 202.5,150 and 137.5 mg/g,respectively.Their behaviors obey the Freundlich isotherm model very well.Additionally,CS/GO10 has the shortest time to achieve adsorption equilibrium among them and can be used as a perspective adsorbent for Cu(Ⅱ).展开更多
The objective of the presented work was to assess the adsorption processes of Cu(Ⅱ) from aqueous solution onto a granular activated carbon (GAC) and a modified activated carbon (MAC) with nitric acid. Available surfa...The objective of the presented work was to assess the adsorption processes of Cu(Ⅱ) from aqueous solution onto a granular activated carbon (GAC) and a modified activated carbon (MAC) with nitric acid. Available surface functional groups, pH of the isoelectric point (pHIEP), and Fourier transform infrared spectroscopes were obtained to characterize the GAC/MAC. Factors influencing Cu(Ⅱ) adsorption such as adsorbent dosage, pH of solution, and contact time of the adsorption onto the MAC/GAC had been investigated in a batch experiment. Experimental equilibrium data had been obtained and modelled using both Freundlich and Langmuir classical adsorption isotherms and the data fitted better to Langmuir isotherm. It was found that nitric acid modification increased the Cu(Ⅱ) adsorption capacity to 90.9 mg/g, which was higher than the unmodified carbon by 41%. Two simplified models including pseudo-first-order and pseudo-second-order equations were selected to follow the adsorption processes.展开更多
An enhanced adsorption and desorption procedure of Cu(II) onto green synthesized acrylic acid grafted polytetrafluoroethylene fiber(i.e. AA-PTFE) was conducted with various chemical methods. The results show that the ...An enhanced adsorption and desorption procedure of Cu(II) onto green synthesized acrylic acid grafted polytetrafluoroethylene fiber(i.e. AA-PTFE) was conducted with various chemical methods. The results show that the optimal adsorption condition is in acetic acid, sodium acetate(HAc-Na Ac) buffer solution(p H=6.80) with the initial concentration of 0.2 mg/mL. The process is very fast initially and equilibrium time is 12 h with a high Cu(II) uptake of 112.26 mg/g at 298 K. Various thermodynamic parameters indicate that the adsorption process is spontaneous and endothermic in nature. In the elution test, 2 mol/L HCl solution achieves satisfactory elution rate and shows no significant decrease after 5 adsorption-desorption cycle, which indicates that AA-PTFE can be regenerated and reused, and due to which a reasonable amount of nondegradable polymer material is avoided in industrial use. Finally, PTFE, AA-PTFE fiber, and Cu(II) loaded AA-PTFE fiber were characterized with various techniques, including IR spectroscopic technique, SEM and EDS.展开更多
基金supported by the key program of the National Natural Science Foundation of China(52236008).
文摘High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.
基金supports from the National Natural Science Foundation of China(No.21776015)the University Scientific Research Project of Anhui Province(No.KJ2018A0065&KJ2020A0245).
文摘Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical reaction of CaC_(2) and a carbonate(CaCO_(3),Na2CO_(3),or NaHCO_(3))at ambient temperature.The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2 g^(-1)),highly crosslinked texture,and rich alkynyl and oxygenated groups.The OACMs exhibit excellent Hg(Ⅱ)adsorption due to the soft acid-soft base interaction between alkynyl and Hg(Ⅱ),and OACM-3 derived from CaC_(2) and NaHCO_(3) has the saturated Hg(Ⅱ)adsorbance of 483.9 mg g^(-1)along with good selectivity and recyclability.The adsorption is mainly chemisorption following the Langmuir mode.OACM-3 also shows high adsorbance for other heavy metal ions,e.g.256.6 mg g^(-1)for Pb(II),232.4 mg g^(-1)for Zn(II),and 198.7 mg g^(-1)for Cu(II).This work expands the mechnochemical reaction of CaC_(2)with carbonates and possibly other oxyanionic salts,provides a new synthesis approach for functional alkynyl carbon materials with excellent adsorption performance for heavy metal ions,as well as a feasible approach for CO2 resource utilization.
基金supported by the Knowledge Innovation Program Foundation of the Chinese Academy of Sciences(No. KZCX2-YW-Q10-3,ISSASIP0713)
文摘The adsorption and desorption of Cu（Ⅱ） and Pb（Ⅱ） on upland red soil,and paddy soils which were originated from the upland soil and cultivated for 8,15,35 and 85 years,were investigated using the batch method.The study showed that the organic matter content and cation exchange capacity （CEC） of the soils are important factors controlling the adsorption and desorption of Cu（Ⅱ） and Pb（Ⅱ）.The 15-Year paddy soil had the highest adsorption capacity for Pb（Ⅱ）,followed by the 35-Year paddy soil.Both the 35-Year paddy soil and 15-Year paddy soil adsorbed more Cu（Ⅱ） than the upland soil and other paddy soils.The 15-Year paddy soils exhibited the highest desorption percentage for both Cu（Ⅱ） and Pb（Ⅱ）.These results are consistent with the trend for the CEC of the soils tested.The high soil CEC contributes not only to the adsorption of Cu（Ⅱ） and Pb（Ⅱ） but also to the electrostatic adsorption of the two heavy metals by the soils.Lower desorption percentages for Cu（Ⅱ） （36.7% to 42.2%） and Pb（Ⅱ） （50.4% to 57.9%） were observed for the 85-Year paddy soil.The highest content of organic matter in the soil was responsible for the low desorption percentages for the two metals because the formation of the complexes between the organic matter and the metals could increase the stability of the heavy metals in the soils.
基金supported by the Key Technologies R&D Program of China (2013BAD07B02 and 2013BAC09B01)the Special Fund for Agro-Scientific Research in the Public Interest of China (201103003)+1 种基金the Postdoctoral Project of Jilin Province, China (01912)the Doctoral Initiative Foundation of Jilin Agricultural University, China (201216)
文摘The adsorption of Cu（Ⅱ） from aqueous solution onto humic acid （HA） which was isolated from cattle manure （CHA）, peat （PHA）, and leaf litter （LHA） as a function of contact time, pH, ion strength, and initial concentration was studied using the batch method. X-ray absorption spectroscopy （XAS） was used to examine the coordination environment of the Cu（ll） adsorbed by HA at a molecular level. Moreover, the chemical compositions of the isolated HA were characterized by elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy （NMR）. The kinetic data showed that the adsorption equilibrium can be achieved within 8 h. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms could be well fitted by the Langmuir model, and the maximum adsorption capacities of Cu（ll） on CHA, PHA, and LHA were 229.4,210.4, and 197.7 mg g-1, respectively. The adsorption of Cu（Ⅱ） on HA increased with the increase in pH from 2 to 7, and maintained a high level at pH〉7. The adsorption of Cu（Ⅱ） was also strongly influenced by the low ionic strength of 0.01 to 0.2 mol L-1 NaNO3, but was weakly influenced by high ionic strength of 0.4 to 1 mol L-1 NaNO3. The Cu（Ⅱ） adsorption on HA may be mainly attributed to ion exchange and surface complexation. XAS results revealed that the binding site and oxidation state of Cu adsorbed on HA surface did not change at the initial Cu（Ⅱ） concentrations of 15 to 40 mg L 1. For all the Cu（Ⅱ） adsorption samples, each Cu atom was surrounded by 40/N atoms at a bond distance of 1.95 A in the first coordination shell. The presence of the higher Cu coordination shells proved that Cu（Ⅱ） was adsorbed via an inner-sphere covalent bond onto the HA surface. Among the three HA samples, the adsorption capacity and affinity of CHA for Cu（Ⅱ） was the greatest, followed by that of PHA and LHA. All the three HA samples exhibited similar types of elemental and functional groups, but different contents of elemental and functional groups. CHA contained larger proportions of methoxyl C, phenolic C and carbonyl C, and smaller proportions of alkyl C and carbohydrate C than PHA and LHA. The structural differences of the three HA samples are responsible for their distinct adsorption capacity and affinity toward Cu（Ⅱ）. These results are important to achieve better understanding of the behavior of Cu（Ⅱ） in soil and water bodies in the presence of organic materials.
基金Projects(51071067,21271069,J1210040,51238002) supported by the National Natural Science Foundation of ChinaProjects(2013GK3015,2012SK3170) supported by the Science and Technology Program of Hunan Province,China
文摘Cross-linked chitosan(CS),cross-linked chitosan/graphene(CS/RGO10) and cross-linked chitosan/graphene oxide(CS/GO10) were prepared as adsorbents for Cu(Ⅱ).The effects of pH,contact time,adsorbent dosage and initial concentration of Cu(Ⅱ) on the adsorbing abilities of CS,CS/RGO10 and CS/GO10 to Cu(Ⅱ) were investigated.The results demonstrate that the adsorption capacities of CS/GO10 and CS/RGO10 are greater than that of CS,especially at pH 5.0 and the adsorption capacities are 202.5,150 and 137.5 mg/g,respectively.Their behaviors obey the Freundlich isotherm model very well.Additionally,CS/GO10 has the shortest time to achieve adsorption equilibrium among them and can be used as a perspective adsorbent for Cu(Ⅱ).
基金The Key Results Promotion of Jiangxi Province,China ( No. 2009CBB00800) Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense,China( No. 2010RGET15) Educational Committee of Jiangxi Province,China( No. GJJ12386)
文摘The objective of the presented work was to assess the adsorption processes of Cu(Ⅱ) from aqueous solution onto a granular activated carbon (GAC) and a modified activated carbon (MAC) with nitric acid. Available surface functional groups, pH of the isoelectric point (pHIEP), and Fourier transform infrared spectroscopes were obtained to characterize the GAC/MAC. Factors influencing Cu(Ⅱ) adsorption such as adsorbent dosage, pH of solution, and contact time of the adsorption onto the MAC/GAC had been investigated in a batch experiment. Experimental equilibrium data had been obtained and modelled using both Freundlich and Langmuir classical adsorption isotherms and the data fitted better to Langmuir isotherm. It was found that nitric acid modification increased the Cu(Ⅱ) adsorption capacity to 90.9 mg/g, which was higher than the unmodified carbon by 41%. Two simplified models including pseudo-first-order and pseudo-second-order equations were selected to follow the adsorption processes.
基金Project(20133326110006)supported by Ph D Programs Foundation of Ministry of Education of ChinaProject(2005002)supported by Zhejiang Provincial Key Laboratory of Fiber Materials and Manufacturing Technology,ChinaProject(YR2015002)supported by Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology of Zhejiang Sci-Tech University,China
文摘An enhanced adsorption and desorption procedure of Cu(II) onto green synthesized acrylic acid grafted polytetrafluoroethylene fiber(i.e. AA-PTFE) was conducted with various chemical methods. The results show that the optimal adsorption condition is in acetic acid, sodium acetate(HAc-Na Ac) buffer solution(p H=6.80) with the initial concentration of 0.2 mg/mL. The process is very fast initially and equilibrium time is 12 h with a high Cu(II) uptake of 112.26 mg/g at 298 K. Various thermodynamic parameters indicate that the adsorption process is spontaneous and endothermic in nature. In the elution test, 2 mol/L HCl solution achieves satisfactory elution rate and shows no significant decrease after 5 adsorption-desorption cycle, which indicates that AA-PTFE can be regenerated and reused, and due to which a reasonable amount of nondegradable polymer material is avoided in industrial use. Finally, PTFE, AA-PTFE fiber, and Cu(II) loaded AA-PTFE fiber were characterized with various techniques, including IR spectroscopic technique, SEM and EDS.
