Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits re...Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits receiving a lethal dose of endotoxin underwent hemoperfusion through immunoadsorbent or Amberlite BAD-7. Plasma TNF levels. efficiency of the adsorbents and the survival rate were observed. Results: After 2 h of hemopcrfusion through immunoadsorhent or Amberlite XAD-7. plasma TNF levels were significantly lower than those in the control group(P<0.01). and the best result was shown by immunoadsorption (P<0. 01). The 12 h and 18 h survival rates were 70% and 30% in the immunoadsorption group, and 30% and 5% in the Amberlite XAD-7 group respectively (P<0. 05). Conclusion: Compared with the nonspecific Amberlite XAD-7 adsorption,the specific imrnunoadsorption might be a more effective method of removing circulatory TNF and improve the survival rate in endotoxin shock.展开更多
Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectivel...Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectively used for the separation and preconcentration of metal ions such as Ni(II), Cu(II), Zn(II) and Cd(II). Critical parameters such as pH, flow rate, sorption capacity, breakthrough studies, distribution coefficient, preconcentration factor, concentration of eluting agents responsible for quantitative extraction of metal ions were optimized. The synthesized resin showed good binding affinity towards Ni(II), Cu(II), Zn(II) and Cd(II) under selective pH conditions. Good breakthrough capacity and fast exchange kinetics of the resin lead to effective separation of metal ions from their binary and ternary mixture by column method on the basis of pH and eluting agents. The resin could be reused for about 8 -10 cycles. The proposed method having the analytical data with the relative standard deviation (RSD) 2% and with recoveries of analytes higher than 98%, reflects upon the reproducibility and reliability of the method which has been successfully applied in the separation and determination of Ni(II), Cu(II), Zn(II) and Cd(II) ions in synthetic, natural and ground water samples.展开更多
Tannic acid and its related compounds are known as refractory organic pollutants, and it can create serious problems for the environment. The adsorption and desorption studies of tannic acid on commercial resins XAD-7...Tannic acid and its related compounds are known as refractory organic pollutants, and it can create serious problems for the environment. The adsorption and desorption studies of tannic acid on commercial resins XAD-7 and D-201 are performed, and all data indicates resin XAD-7 can be used as an effective adsorbent for removing tannic acid during water/wastewater treatment. Furthermore, adsorption thermodynamics studies indicate different adsorption mechanisms for TA on XAD-7 and D-201. FT-IR and solid state 13C-NMR spectroscopy are used to explain the adsorption force between XAD-7 and TA. It suggests that hydrogen bonding is the main adsorption force for TA. Finally, XAD-7＇s adsorption capacity in the presence of different metal ions is investigated, which indicates that heavy metal ions in solutions can decrease the adsorption capacity for TA on ester resin XAD-7.展开更多
The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resi...The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with stirring.The effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were studied.The most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping solution.Up to 80% yttrium is extracted,while 75% yttrium is recovered in the striping solution.In all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order model.Also,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is 1.5.Cyclic tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its efficiency.Finally,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.展开更多
A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in ...A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume, concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn^2＋ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g^-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L^-1 （n=20, blank＋ 3s）. The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.展开更多
New adso rbent material was obtained by modification of commercial Amberlite XAD7 with thiourea that represents a non-toxic,cheap and environmentally friendly extractant.Prepared adsorbent was used for removal of neod...New adso rbent material was obtained by modification of commercial Amberlite XAD7 with thiourea that represents a non-toxic,cheap and environmentally friendly extractant.Prepared adsorbent was used for removal of neodymium ions from aqueous solutions.Thiourea modified Amberlite involved in this study shows good adsorption capacities(74.3 mg/g) and excellent efficiency during Nd removal process.In order to elucidate the mechanism of the Nd adsorption process kinetic,thermodynamic and equilibrium studies were performed,establishing this way which kinetic model better describes the Nd adsorption process.Moreover the thermodynamic studies prove that the Nd adsorption on thiourea modified Amberlite XAD7 is an endothermic and spontaneous process.展开更多
A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion ...A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.展开更多
文摘Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits receiving a lethal dose of endotoxin underwent hemoperfusion through immunoadsorbent or Amberlite BAD-7. Plasma TNF levels. efficiency of the adsorbents and the survival rate were observed. Results: After 2 h of hemopcrfusion through immunoadsorhent or Amberlite XAD-7. plasma TNF levels were significantly lower than those in the control group(P<0.01). and the best result was shown by immunoadsorption (P<0. 01). The 12 h and 18 h survival rates were 70% and 30% in the immunoadsorption group, and 30% and 5% in the Amberlite XAD-7 group respectively (P<0. 05). Conclusion: Compared with the nonspecific Amberlite XAD-7 adsorption,the specific imrnunoadsorption might be a more effective method of removing circulatory TNF and improve the survival rate in endotoxin shock.
文摘Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectively used for the separation and preconcentration of metal ions such as Ni(II), Cu(II), Zn(II) and Cd(II). Critical parameters such as pH, flow rate, sorption capacity, breakthrough studies, distribution coefficient, preconcentration factor, concentration of eluting agents responsible for quantitative extraction of metal ions were optimized. The synthesized resin showed good binding affinity towards Ni(II), Cu(II), Zn(II) and Cd(II) under selective pH conditions. Good breakthrough capacity and fast exchange kinetics of the resin lead to effective separation of metal ions from their binary and ternary mixture by column method on the basis of pH and eluting agents. The resin could be reused for about 8 -10 cycles. The proposed method having the analytical data with the relative standard deviation (RSD) 2% and with recoveries of analytes higher than 98%, reflects upon the reproducibility and reliability of the method which has been successfully applied in the separation and determination of Ni(II), Cu(II), Zn(II) and Cd(II) ions in synthetic, natural and ground water samples.
基金supported by the National Natural Science Fundation of China(No.50778088)China National Funds for Distinguished Young Scientists(No.50825802)
文摘Tannic acid and its related compounds are known as refractory organic pollutants, and it can create serious problems for the environment. The adsorption and desorption studies of tannic acid on commercial resins XAD-7 and D-201 are performed, and all data indicates resin XAD-7 can be used as an effective adsorbent for removing tannic acid during water/wastewater treatment. Furthermore, adsorption thermodynamics studies indicate different adsorption mechanisms for TA on XAD-7 and D-201. FT-IR and solid state 13C-NMR spectroscopy are used to explain the adsorption force between XAD-7 and TA. It suggests that hydrogen bonding is the main adsorption force for TA. Finally, XAD-7＇s adsorption capacity in the presence of different metal ions is investigated, which indicates that heavy metal ions in solutions can decrease the adsorption capacity for TA on ester resin XAD-7.
基金Project supported by Secretariat of Research and Postgraduate Studies National Polytechnic Institute (20221369 and 20231939)Consejo Nacional de Ciencia y Tecnologia CONACyT。
文摘The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with stirring.The effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were studied.The most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping solution.Up to 80% yttrium is extracted,while 75% yttrium is recovered in the striping solution.In all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order model.Also,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is 1.5.Cyclic tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its efficiency.Finally,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.
文摘A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume, concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn^2＋ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g^-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L^-1 （n=20, blank＋ 3s）. The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.
文摘New adso rbent material was obtained by modification of commercial Amberlite XAD7 with thiourea that represents a non-toxic,cheap and environmentally friendly extractant.Prepared adsorbent was used for removal of neodymium ions from aqueous solutions.Thiourea modified Amberlite involved in this study shows good adsorption capacities(74.3 mg/g) and excellent efficiency during Nd removal process.In order to elucidate the mechanism of the Nd adsorption process kinetic,thermodynamic and equilibrium studies were performed,establishing this way which kinetic model better describes the Nd adsorption process.Moreover the thermodynamic studies prove that the Nd adsorption on thiourea modified Amberlite XAD7 is an endothermic and spontaneous process.
文摘A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.
