The influences of medium pH sorption temperature, sorption time, etc. on thesorption capacity of macroporous Phosphonic acid resin for La3+ were determined Thesorption rate constant was k298 = 7.64×10-5 s-1. The ...The influences of medium pH sorption temperature, sorption time, etc. on thesorption capacity of macroporous Phosphonic acid resin for La3+ were determined Thesorption rate constant was k298 = 7.64×10-5 s-1. The complex ratio of phosphonicgroups of the resin to La3+ was 3:1. The basic sorption parameters were determinedThe sorption mechanism of macroporous phosphonic acid resin for La3+ was examinedby chemical analysis and IR- spectrometry.展开更多
This paper reports the study on the polymer protected catalyst CPVC-FeCl3 used in esterification,transesterification,synthesis of acetals or ketals and rearrangement reaction of pinacol.The catalyst has the advantages...This paper reports the study on the polymer protected catalyst CPVC-FeCl3 used in esterification,transesterification,synthesis of acetals or ketals and rearrangement reaction of pinacol.The catalyst has the advantages of being simple in operation,non-corrosive,easy to separate from mixtures and good reusability.展开更多
The sorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR), for Sm(lll) were investigated. The optimal sorption condition of DAAR for Sm(lll) is pH=6.0 in HAc-NaAc medium. The sta...The sorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR), for Sm(lll) were investigated. The optimal sorption condition of DAAR for Sm(lll) is pH=6.0 in HAc-NaAc medium. The statically saturated sorption capacity is 190mg/g resin at 298K. The Sm(lll) adsorbed on DAAR can be eluted reaching 100% by 0.5-2.0mol/L HCI used as eluant. The resin can be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant is k298= 1.96×10^-5s^-1. The apparent activation energy is 26kJ/mol. The sorption behavior of DAAR for Sm(lll) obeys the Freundlich isotherm. The thermodynamic sorption parameters, enthalpy change ΔH of DAAR for Sm(lll) is 16.9Kl/mol. The molar coordination ratio of the functional group of DAAR to Sin (111) is 3. The sorption mechanism of DAAR for Sm(lll) was examined by using chemical method and IR spectrometry. The coordination bond was formed between oxygen atoms in the functional group of DAAR and Sin(Ill).展开更多
The treatment of salicylic acid manufacturing wastewater by NDA-100 resin wasinvestigated. The sorption intensity of phenol was found to be strongly dependent on pH of theaqueous phase. Equilibrium adsorption data fit...The treatment of salicylic acid manufacturing wastewater by NDA-100 resin wasinvestigated. The sorption intensity of phenol was found to be strongly dependent on pH of theaqueous phase. Equilibrium adsorption data fit to both Langmuir and Freundlich models. Thecolumn adsorption showed thatthis process was suitable for the treatment of salicylic acidmanufacturing wastewater About 99.9% CODcr removal was obtained under the optimal operatingconditions. The resin could be completely regenerated with 1 BV8%(w/w) NaOH+2BV H2O, therecovery of 98.9% of the substance was reached. This process makes it possible to recover thevaluable material from the wastewater and to improve the effluent water quality.展开更多
Water-blown polyurethane rigid foams are getting more and more attention,because the traditional blowing agent HCFC141b has already been abolished to prevent the ozone layer from destruction.However,the polyurethane r...Water-blown polyurethane rigid foams are getting more and more attention,because the traditional blowing agent HCFC141b has already been abolished to prevent the ozone layer from destruction.However,the polyurethane rigid foams blown by water have serious defects,i.e.friability and resulting lower adhesion strength.Thus,the purpose of this study is to resolve the problems by chemical plastication.The maleate was added to polyol-premix containing water or to polyisocyanate,with both of which maleate does not react.To prove the reaction when polyol-premix and polyisocyanate were mixed,the model composite was synthesized and analyzed by IR,NMR and ESI(MS).Furthermore,a series of water-blown polyurethane rigid foams added different amount maleate were successfully prepared.By testing impact strength and adhesion strength of the foams,the actual effect of adding maleate was obtained.展开更多
The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-la...The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-layer absorption. It is of interest to notice that the effect of pH on the adsorption of 2.4-or 2,6-dinitrophenol onto ADS-7 and ADS-21 was very small. The result is explained by hydrogen bonding interaction between 2, 4- or 2. 6-dinitrophenol and the adsorbent ADS21. The large adsorption capacity of dinitrophenol onto ADS-21, which was about 500 mg/g at an equilibrium concentration of 400 mg/L. and the small dinitrophenol leakage in the effluent from ADS- 21 column presented a good prospect for treatment of wastewater containing dinitrophenol with absorbent ADS-21.展开更多
The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on ads...The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on adsorption was discussed. Experimental results indicate that the active centre of regenerable chitin is the free amino groups on its surface, and that the rate of adsorption of free acid was found to be affected by two factors: the interaction between the adsorbent and the adsorbate in solution and that between the adsorbate molecules or ions in solution.展开更多
The adsorption kinetics and mechanism of a novel chelate resin, macroporous phosphonic acid resin (PAR) for In(III) were investigated. The statically saturated adsorption capacity is 216mg穏-1resin at 298K in HAc-NaAc...The adsorption kinetics and mechanism of a novel chelate resin, macroporous phosphonic acid resin (PAR) for In(III) were investigated. The statically saturated adsorption capacity is 216mg穏-1resin at 298K in HAc-NaAc medium. The apparent adsorption rate constant is k298=4.84?0-5 s-1. The adsorption behavior of PAR for In(III) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change △H, free energy change △G and entropy change △S of PAR for In(III) are 11.5kJ/mol, -12.6kJ/mol and 80.8J/mol稫, respectively. The apparent activation energy is Ea=3.5kJ/mol. The molar coordination ratio of the functional group of PAR to In(III) is about 3∶1.展开更多
The surface of polypropylene (PP) membrane was modified by low temperature plasma with ammonia. The effect of exposure time was investigated by means of contact angle measurement. The results show that low temperature...The surface of polypropylene (PP) membrane was modified by low temperature plasma with ammonia. The effect of exposure time was investigated by means of contact angle measurement. The results show that low temperature ammonia plasma treatment can enhance its hydrophilicity. Chinese hamster ovary (CHO) cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.展开更多
Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this...Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this paper.Under the operation conditionsof initial β-salt concentration of 10000-25000mg/L and initial CODcr of 2000040000mg/L, the removal rates of Sodium 2-Naphthylsulfonate and CODcr are over 95%and over 89%, respectively. The effluent can be discharged directly after biologicaldegradation. The working sorption capacity of ND-910 Resin for β-salt is over 230g/Kg.An alkali-water wash procedure is utilized to regenerate resin and the reclaiming rate ofβ-salt is over 98%.展开更多
In this paper,the two effluents from PBA (3-phenoxy-benzaldehyde) production process were treated by polymeric adsorbent CHA-111.PBA or PBC (3-phenoxy-benzoic acid) was recovered from the wastewater in the process of ...In this paper,the two effluents from PBA (3-phenoxy-benzaldehyde) production process were treated by polymeric adsorbent CHA-111.PBA or PBC (3-phenoxy-benzoic acid) was recovered from the wastewater in the process of neutralization.As a secondary treatment method,adsorption with CHA-111 showed better efficiency than photocatolytic decomposition and solvent extraction.The optimal technological parameters were:adsorption:current velocity:2.0BV/hr(bed volume per hour),room temperature;desorption:current velocity:2.0BV/hr(bed volume per hour),room temperature;desorption:current velocity:1.0 BV/hr,80℃,8% sodium hydroxide aqueous solutions.In conclusion,99.9% COD in the neutralizing wastewater and 98.4% COD in the hydrolysis wastewater are removed successfully.展开更多
FGS was isolated and purified from laminaria japonica by enzymolysis, chromatography methods and so on. The high blood fat model was established by feeding mouse on high fat feedstuff. Compared with control group, the...FGS was isolated and purified from laminaria japonica by enzymolysis, chromatography methods and so on. The high blood fat model was established by feeding mouse on high fat feedstuff. Compared with control group, the concentration of HDL-C, the ratio of HDL-C/TC increased;while the concentration of TC, LDL-C and TG decreased in experimental groups. Conclusion: FGS was an effective serum lipid regulator and can be developed as medicine and health food.展开更多
The succinylation of cornstarch by slurry reaction has been studied using sodium hydroxide as catalyst. Several reaction parameters afJecting the succinylation were investigated including the concentration of starch i...The succinylation of cornstarch by slurry reaction has been studied using sodium hydroxide as catalyst. Several reaction parameters afJecting the succinylation were investigated including the concentration of starch in water, the ratio of succinic anhydride to starch, the reaction time and the reaction temperature. The favorable conditions for an intermediate degree of substitution (DS) and reasonably high reaction efficiency (RE) are pH 8.5~9.0, 50% starch by weight to water, succinic anhydride to starch I/I (w/w), reaction time 4h, reaction temperature 30 ℃Under these conditions, the DS of 0.45 and RE of 28% were achieved. The addition of an adequate amount of crosslinking agent imparted starch succinate water absorbency.展开更多
A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption o...A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption of tannin from aqueous solution onto the adsorbent were investigated. Most of the differential adsorption heats for various adsorption capacities calculated from the adsorption isotherms according to Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). Adsorption properties of the adsorbent were studied in detail. These results revealed a hydrogen bonding mechanism of the adsorption of tannin from aqueous solution onto the adsorbent. The result of the dynamic adsorption of tanning with the initial concentration under 600 mg/L showed that the adsorption rate of tannin exceeded 90% when the flow rate was 3BV/h and the effluent volume reached 100 BV. Therefore, the developed hydrogen-bonding adsorbent--macroporous crosslinked poly(N-vinyl-acetamide)—is an excellent adsorbent to remove tannin from extract of natural products. and has great value in application.展开更多
Sm(III) was quantitatively adsorbed by amino methylene phosphonic acid resin (APAR) in the medium of pH=5.0. The statically saturated sorption capacity is 251mg/g·resin. Sm(III) adsorbed on APAR can be reductivel...Sm(III) was quantitatively adsorbed by amino methylene phosphonic acid resin (APAR) in the medium of pH=5.0. The statically saturated sorption capacity is 251mg/g·resin. Sm(III) adsorbed on APAR can be reductively eluted by 2.0mol/L HCl. The sorption rate constant is k298= 1.35×10-5s-1. The sorption behavior of APAR for Sm(III) obeys the Freundlich isotherm. The enthalpy change △H of sorption is 24.9kJ/mol. The apparent activation energy is Ea=11.7kJ/mol. The sorption mechanism shows that the nitrogen and oxygen atoms of the functional group of APAR coordinated with Sm(III) to form coordination bond.展开更多
Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure wer...Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure were characterized by measurements of surface area, apparent density and skeleton density and calculation of average pore diameter The results revealed that crosslinking degree and porogent determined the physical structure of these copolymers. Some of the copolymers were applied to adsorptive purification of ginkgo leaves extract to enhance the content of flavonoids, the results showed that most of the copolymers could be used to increase the flavonoids content.展开更多
Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liqu...Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liquor and filtrate after acidifying and settling were sonicated. The effect of working parameters on ultrasonic degradation of black liquor, such as different combination methods, frequency, power supply, initial concentration, pH, duration time, ionic strength and catalyst were studied. The results were as follows: (1) At the conditions of 40kHz, 100W, 4h, pH at 6 and temperature 30?℃, utilizing US/US-H2O2/US-Fenton, weak-orange filtrate turned to colloid with the increase of time and little sediment produced after settling. Especially filtrate came to be milk white collides and upper water approached to nearly achromatic by US-Fenton. Compared with the US, US-H2O2/US-Fenton COD (Chemical oxidation demand) removal ratio can increase 15%, 30% respectively. Because of more hydroxyl radicals produced in the reaction process; (2) At the condition of 100W and 4h, the degradation efficiency of black liquor was better at 40kHz over at 20kHz. Moreover black liquor can be biodegraded easily. Those based on that the big molecule of contaminants in aqueous solution can be changed into the little molecule with ultrasound (3) At the condition of 40kHz and 4h, the COD removal ratio of black liquor was more higher at 60W than at 80W, while the removal ratio of COD at 60W was nearly close to the ratio at 100W; (4) The initial concentration of black liquor influenced the effect of sonochemical degradation; (5) The variation of pH had no effect on degradation; (6) The longer the duration time, the greater the removal ratio of COD. But this ratio increased slowly after 4h; (7) Adding 0.2g/L NaCl to change the ionic strength of the black liquor, the COD removal ratio can increase 10%; (8) The degradation rates increased by the coexistent catalysts of TiO2, Co2+ and Ag+.展开更多
A series of modified poly (methyl methacrylate, PMMA) resins were prepared and compared their adsorption abilities to endotoxin. The results showed that adsorbents, which were grafted with tertiary amine and long spac...A series of modified poly (methyl methacrylate, PMMA) resins were prepared and compared their adsorption abilities to endotoxin. The results showed that adsorbents, which were grafted with tertiary amine and long spacing arms, had the best adsorption capacities and good blood compatibility. It is hopeful to be used as adsorbent in hemoperfusion for clinical clearance of endotoxin. The influence of original concentration of endotoxin on adsorption and the adsorption mechanism were also investigated.展开更多
The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency an...The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+, this suggested that the coordination strength of Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+.展开更多
文摘The influences of medium pH sorption temperature, sorption time, etc. on thesorption capacity of macroporous Phosphonic acid resin for La3+ were determined Thesorption rate constant was k298 = 7.64×10-5 s-1. The complex ratio of phosphonicgroups of the resin to La3+ was 3:1. The basic sorption parameters were determinedThe sorption mechanism of macroporous phosphonic acid resin for La3+ was examinedby chemical analysis and IR- spectrometry.
文摘This paper reports the study on the polymer protected catalyst CPVC-FeCl3 used in esterification,transesterification,synthesis of acetals or ketals and rearrangement reaction of pinacol.The catalyst has the advantages of being simple in operation,non-corrosive,easy to separate from mixtures and good reusability.
基金The Natural Science Foundation of Zhejiang Province (No.200072)
文摘The sorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR), for Sm(lll) were investigated. The optimal sorption condition of DAAR for Sm(lll) is pH=6.0 in HAc-NaAc medium. The statically saturated sorption capacity is 190mg/g resin at 298K. The Sm(lll) adsorbed on DAAR can be eluted reaching 100% by 0.5-2.0mol/L HCI used as eluant. The resin can be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant is k298= 1.96×10^-5s^-1. The apparent activation energy is 26kJ/mol. The sorption behavior of DAAR for Sm(lll) obeys the Freundlich isotherm. The thermodynamic sorption parameters, enthalpy change ΔH of DAAR for Sm(lll) is 16.9Kl/mol. The molar coordination ratio of the functional group of DAAR to Sin (111) is 3. The sorption mechanism of DAAR for Sm(lll) was examined by using chemical method and IR spectrometry. The coordination bond was formed between oxygen atoms in the functional group of DAAR and Sin(Ill).
文摘The treatment of salicylic acid manufacturing wastewater by NDA-100 resin wasinvestigated. The sorption intensity of phenol was found to be strongly dependent on pH of theaqueous phase. Equilibrium adsorption data fit to both Langmuir and Freundlich models. Thecolumn adsorption showed thatthis process was suitable for the treatment of salicylic acidmanufacturing wastewater About 99.9% CODcr removal was obtained under the optimal operatingconditions. The resin could be completely regenerated with 1 BV8%(w/w) NaOH+2BV H2O, therecovery of 98.9% of the substance was reached. This process makes it possible to recover thevaluable material from the wastewater and to improve the effluent water quality.
文摘Water-blown polyurethane rigid foams are getting more and more attention,because the traditional blowing agent HCFC141b has already been abolished to prevent the ozone layer from destruction.However,the polyurethane rigid foams blown by water have serious defects,i.e.friability and resulting lower adhesion strength.Thus,the purpose of this study is to resolve the problems by chemical plastication.The maleate was added to polyol-premix containing water or to polyisocyanate,with both of which maleate does not react.To prove the reaction when polyol-premix and polyisocyanate were mixed,the model composite was synthesized and analyzed by IR,NMR and ESI(MS).Furthermore,a series of water-blown polyurethane rigid foams added different amount maleate were successfully prepared.By testing impact strength and adhesion strength of the foams,the actual effect of adding maleate was obtained.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164)
文摘The adsorption of 2,4-dinitrophenol and 2.6-dinitrophenol on non-polar and polar adsorbents was studied. The results showed that the equilibrium adsorption did not comply with the Langmuir equation and was not mono-layer absorption. It is of interest to notice that the effect of pH on the adsorption of 2.4-or 2,6-dinitrophenol onto ADS-7 and ADS-21 was very small. The result is explained by hydrogen bonding interaction between 2, 4- or 2. 6-dinitrophenol and the adsorbent ADS21. The large adsorption capacity of dinitrophenol onto ADS-21, which was about 500 mg/g at an equilibrium concentration of 400 mg/L. and the small dinitrophenol leakage in the effluent from ADS- 21 column presented a good prospect for treatment of wastewater containing dinitrophenol with absorbent ADS-21.
文摘The adsorption of low concentration of free acid by regenerable chitin is followed by electric conductance determination. The effect of acid concentration, content of functional amino groups, and ionic strength on adsorption was discussed. Experimental results indicate that the active centre of regenerable chitin is the free amino groups on its surface, and that the rate of adsorption of free acid was found to be affected by two factors: the interaction between the adsorbent and the adsorbate in solution and that between the adsorbate molecules or ions in solution.
基金Zhoushan Science & Technology Bureau (No. 04114)
文摘The adsorption kinetics and mechanism of a novel chelate resin, macroporous phosphonic acid resin (PAR) for In(III) were investigated. The statically saturated adsorption capacity is 216mg穏-1resin at 298K in HAc-NaAc medium. The apparent adsorption rate constant is k298=4.84?0-5 s-1. The adsorption behavior of PAR for In(III) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change △H, free energy change △G and entropy change △S of PAR for In(III) are 11.5kJ/mol, -12.6kJ/mol and 80.8J/mol稫, respectively. The apparent activation energy is Ea=3.5kJ/mol. The molar coordination ratio of the functional group of PAR to In(III) is about 3∶1.
基金The National Natural Science Foundation of China (No. 29776027)
文摘The surface of polypropylene (PP) membrane was modified by low temperature plasma with ammonia. The effect of exposure time was investigated by means of contact angle measurement. The results show that low temperature ammonia plasma treatment can enhance its hydrophilicity. Chinese hamster ovary (CHO) cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.
文摘Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this paper.Under the operation conditionsof initial β-salt concentration of 10000-25000mg/L and initial CODcr of 2000040000mg/L, the removal rates of Sodium 2-Naphthylsulfonate and CODcr are over 95%and over 89%, respectively. The effluent can be discharged directly after biologicaldegradation. The working sorption capacity of ND-910 Resin for β-salt is over 230g/Kg.An alkali-water wash procedure is utilized to regenerate resin and the reclaiming rate ofβ-salt is over 98%.
文摘In this paper,the two effluents from PBA (3-phenoxy-benzaldehyde) production process were treated by polymeric adsorbent CHA-111.PBA or PBC (3-phenoxy-benzoic acid) was recovered from the wastewater in the process of neutralization.As a secondary treatment method,adsorption with CHA-111 showed better efficiency than photocatolytic decomposition and solvent extraction.The optimal technological parameters were:adsorption:current velocity:2.0BV/hr(bed volume per hour),room temperature;desorption:current velocity:2.0BV/hr(bed volume per hour),room temperature;desorption:current velocity:1.0 BV/hr,80℃,8% sodium hydroxide aqueous solutions.In conclusion,99.9% COD in the neutralizing wastewater and 98.4% COD in the hydrolysis wastewater are removed successfully.
文摘FGS was isolated and purified from laminaria japonica by enzymolysis, chromatography methods and so on. The high blood fat model was established by feeding mouse on high fat feedstuff. Compared with control group, the concentration of HDL-C, the ratio of HDL-C/TC increased;while the concentration of TC, LDL-C and TG decreased in experimental groups. Conclusion: FGS was an effective serum lipid regulator and can be developed as medicine and health food.
文摘The succinylation of cornstarch by slurry reaction has been studied using sodium hydroxide as catalyst. Several reaction parameters afJecting the succinylation were investigated including the concentration of starch in water, the ratio of succinic anhydride to starch, the reaction time and the reaction temperature. The favorable conditions for an intermediate degree of substitution (DS) and reasonably high reaction efficiency (RE) are pH 8.5~9.0, 50% starch by weight to water, succinic anhydride to starch I/I (w/w), reaction time 4h, reaction temperature 30 ℃Under these conditions, the DS of 0.45 and RE of 28% were achieved. The addition of an adequate amount of crosslinking agent imparted starch succinate water absorbency.
基金Supported by the National Natural Science Foundation of China! (Grant No. 29574164)
文摘A strongly hydrophilic hydrogen-bonding adsorbent-macroporous crosslinked poly(N- vinyl-acetamide). which contain both hydrogen bond acceptor and donator, was synthesized. Adsorption mechanism and dynamic adsorption of tannin from aqueous solution onto the adsorbent were investigated. Most of the differential adsorption heats for various adsorption capacities calculated from the adsorption isotherms according to Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). Adsorption properties of the adsorbent were studied in detail. These results revealed a hydrogen bonding mechanism of the adsorption of tannin from aqueous solution onto the adsorbent. The result of the dynamic adsorption of tanning with the initial concentration under 600 mg/L showed that the adsorption rate of tannin exceeded 90% when the flow rate was 3BV/h and the effluent volume reached 100 BV. Therefore, the developed hydrogen-bonding adsorbent--macroporous crosslinked poly(N-vinyl-acetamide)—is an excellent adsorbent to remove tannin from extract of natural products. and has great value in application.
基金Foundations of Zhejiang Provincial Education Ministry (No.20010677)
文摘Sm(III) was quantitatively adsorbed by amino methylene phosphonic acid resin (APAR) in the medium of pH=5.0. The statically saturated sorption capacity is 251mg/g·resin. Sm(III) adsorbed on APAR can be reductively eluted by 2.0mol/L HCl. The sorption rate constant is k298= 1.35×10-5s-1. The sorption behavior of APAR for Sm(III) obeys the Freundlich isotherm. The enthalpy change △H of sorption is 24.9kJ/mol. The apparent activation energy is Ea=11.7kJ/mol. The sorption mechanism shows that the nitrogen and oxygen atoms of the functional group of APAR coordinated with Sm(III) to form coordination bond.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164)
文摘Spherical macroporous copolymers of methyl acrylate and trimethylolpropane triacrylate with different surface and pore structure were synthesized via suspension polymerization. and their surface and pore structure were characterized by measurements of surface area, apparent density and skeleton density and calculation of average pore diameter The results revealed that crosslinking degree and porogent determined the physical structure of these copolymers. Some of the copolymers were applied to adsorptive purification of ginkgo leaves extract to enhance the content of flavonoids, the results showed that most of the copolymers could be used to increase the flavonoids content.
文摘Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liquor and filtrate after acidifying and settling were sonicated. The effect of working parameters on ultrasonic degradation of black liquor, such as different combination methods, frequency, power supply, initial concentration, pH, duration time, ionic strength and catalyst were studied. The results were as follows: (1) At the conditions of 40kHz, 100W, 4h, pH at 6 and temperature 30?℃, utilizing US/US-H2O2/US-Fenton, weak-orange filtrate turned to colloid with the increase of time and little sediment produced after settling. Especially filtrate came to be milk white collides and upper water approached to nearly achromatic by US-Fenton. Compared with the US, US-H2O2/US-Fenton COD (Chemical oxidation demand) removal ratio can increase 15%, 30% respectively. Because of more hydroxyl radicals produced in the reaction process; (2) At the condition of 100W and 4h, the degradation efficiency of black liquor was better at 40kHz over at 20kHz. Moreover black liquor can be biodegraded easily. Those based on that the big molecule of contaminants in aqueous solution can be changed into the little molecule with ultrasound (3) At the condition of 40kHz and 4h, the COD removal ratio of black liquor was more higher at 60W than at 80W, while the removal ratio of COD at 60W was nearly close to the ratio at 100W; (4) The initial concentration of black liquor influenced the effect of sonochemical degradation; (5) The variation of pH had no effect on degradation; (6) The longer the duration time, the greater the removal ratio of COD. But this ratio increased slowly after 4h; (7) Adding 0.2g/L NaCl to change the ionic strength of the black liquor, the COD removal ratio can increase 10%; (8) The degradation rates increased by the coexistent catalysts of TiO2, Co2+ and Ag+.
基金"973"(G1999064707)(973),Trans-Century Training Programme Foundation for the Talents and Nature Science Foundation of Tianjin (013614011).
文摘A series of modified poly (methyl methacrylate, PMMA) resins were prepared and compared their adsorption abilities to endotoxin. The results showed that adsorbents, which were grafted with tertiary amine and long spacing arms, had the best adsorption capacities and good blood compatibility. It is hopeful to be used as adsorbent in hemoperfusion for clinical clearance of endotoxin. The influence of original concentration of endotoxin on adsorption and the adsorption mechanism were also investigated.
基金The Ph. D. Foundation (Y030426) and Post-doctoral Foundation of China University of Petroleum (East China).
文摘The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+, this suggested that the coordination strength of Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+.