[Objective] This study aimed to explore the synergistic effect of oligochi- tosan and EM bacteria and provide a theoretical basis for its application in animal health, aquaculture, sewage treatment and other fields. [...[Objective] This study aimed to explore the synergistic effect of oligochi- tosan and EM bacteria and provide a theoretical basis for its application in animal health, aquaculture, sewage treatment and other fields. [Method] Different concentrations of oligochitosan were added into EM bacteria liquid and the stability was preliminarily studied. [Result] Addition of oligochitosan with appropriate proportion had played a supporting role in the stable storage of EM bacteria liquid and had shown certain inhibition effect on flatulence of EM bacteria liquid. Addition of oligochitosan had no significant effect on the quality and re-fermentation of EM bacteria. [Conclusion] The study indicated that oligochitosan could be utilized in conjunction with EM bacteria liquid, having a promising practical potential application.展开更多
Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reacti...Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reaction time and chitosan dosage were optimized. Under the optimum experiment condition, the effect of common ions on the adsorption of Cr （i.e., Na^＋, K^＋, Mg^2＋, Ca^2＋ for Cr（Ⅲ）, and Cl^-, NO3^-, SO4^2- for Cr（Ⅵ）） was also investigated. Furthermore, the sorption mechanism of Cr by chitosan was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the chitosan, the surface morphology of the biomass was determined by SEM （scanning electron microscope） and specific surface area analyzer （N2-BET （Brunaeur, Emmet and Teller））. Consequently, the following matters have been mainly clarified： （1） chitosan can be an efficient sorbent for Cr （both Cr（Ⅲ） and Cr（Ⅵ））; （2） the effect of common ions on the adsorption ofCr （Cr（Ⅲ） and Cr（Ⅵ）） was not significant under this experimental conditions; （3） adsorption isotherms using the chitosan can be generally described by Langmuir isotherm more satisfactorily for Cr. The adsorption may have occurred mainly by monolayer reaction; （4） the rates of adsorption were found to conform to pseudo-second order kinetics.展开更多
This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption exp...This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr（Ⅵ） using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr（Ⅵ） adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry） in order to determine the optimum conditions for Cr（Ⅵ） adsorption. Furthermore, the adsorption mechanism of Cr（Ⅵ） by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.展开更多
In this study, quaternized chitosan microspheres （QCMS） were prepared and its Cr （VI） removal potential was investigated. Batch experiments were conducted to examine kinetics, adsorption isotherm, pH effect, and t...In this study, quaternized chitosan microspheres （QCMS） were prepared and its Cr （VI） removal potential was investigated. Batch experiments were conducted to examine kinetics, adsorption isotherm, pH effect, and thermodynamic parameters. Equilibrium was attained within 50 rain and maximum removal of 97.34% was achieved under the optimum conditions at pH 5. Adsorption data for Cr （VI） uptake by the QCMS were analyzed according to Langmuir, Freundlich, and Temkin adsorption models. The maximum uptake of Cr （VI） was 39.1 mg.g-a. Thermodynamic parameters for the adsorption system were determinated at 293 K, 303 K, 313 K and 323 K. （AH° = 16.08 kJ.mol- 1;AG° = -5.84 to -8.08 kJ.mo1-1 and AS° = 74.81 J.K-1 .tool-l）. So the positive values of both A/-F and AS° suggest an endothermic reaction and increase in randomness at the solid-liquid interface during the adsorption. AG° values obtained were negative indicating a spontaneous adsorp- tion process. The kinetic process was described by a pseudo-second-order rate equation very well. The results of the present study indicated that the QCMS could he considered as a potential adsorbent for Cr （V1） in aqueous solutions.展开更多
Poly(styrene-glycidyl methacrylate) particles having bowl-shaped hollow structures were synthesized by swollen seed emulsion polymerization. The PS emulsion synthesized through soap-free emulsion polymerization was sw...Poly(styrene-glycidyl methacrylate) particles having bowl-shaped hollow structures were synthesized by swollen seed emulsion polymerization. The PS emulsion synthesized through soap-free emulsion polymerization was swollen by toluene, and then the mixture of second monomers was added under polymerization condition. So a thin shell of poly(styrene-glycidyl methacrylate) cross-linked by triethylene glycol diacrylate was formed around the swollen PS particle. The bowl-shaped particles were obtained after the collapsing of the thin shell when the toluene emanated from the particles, but the shapes were effected by the degrees of cross-linking. The shape of the particles was observed by SEM. The release behavior of solvent from the particles was examined by TG.展开更多
Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple proc...Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple process of two steps. Characterization of the obtained adsorbents was studied by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. The adsorption kinetics and equilibrium isotherms were in- vestigated in batch experiments. The Langmuir, Freundlich isotherm and pseudo-second order kinetic models agree well with the experimental data. The adsorption of As（III） onto CS/Fe3OdFe（OH）3 microspheres occurred rapidly and reached adsorption equilibrium after about 45 min. The maximum adsorption capacity of CS/Fe3OJFe（OH）3 microspheres, calculated by the Langmuir isotherm model, was 8.47 mg g 1, which is higher than that of CS/Fe304/Fe（OH）3 prepared by the conventional method （4.72 mg g-l）. The results showed that the microspheres had a high adsorption capacity for As（III） and a high separation efficiency due to their microporous structure and superparamagnetic characteristics. Present research may eventually lead to a simple and low cost method for fabricating microporous materials and application for removal of arsenic from aqueous solution.展开更多
Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ...Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ℃ on the growth and physiological changes were investigated using two maize （Zea rnays L.） inbred lines, HuangC （chilling-tolerant） and Mo17 （chilling-sensitive）. While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time （MGT）, and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde （MDA） content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase （POD） activity, and catalase （CAT） activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60-64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.展开更多
The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by i...The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis(TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction(WAXD) and scanning electron microscope(SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin.展开更多
文摘[Objective] This study aimed to explore the synergistic effect of oligochi- tosan and EM bacteria and provide a theoretical basis for its application in animal health, aquaculture, sewage treatment and other fields. [Method] Different concentrations of oligochitosan were added into EM bacteria liquid and the stability was preliminarily studied. [Result] Addition of oligochitosan with appropriate proportion had played a supporting role in the stable storage of EM bacteria liquid and had shown certain inhibition effect on flatulence of EM bacteria liquid. Addition of oligochitosan had no significant effect on the quality and re-fermentation of EM bacteria. [Conclusion] The study indicated that oligochitosan could be utilized in conjunction with EM bacteria liquid, having a promising practical potential application.
文摘Adsorption experiment from aqueous solutions containing known amount of Cr （chromium） using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reaction time and chitosan dosage were optimized. Under the optimum experiment condition, the effect of common ions on the adsorption of Cr （i.e., Na^＋, K^＋, Mg^2＋, Ca^2＋ for Cr（Ⅲ）, and Cl^-, NO3^-, SO4^2- for Cr（Ⅵ）） was also investigated. Furthermore, the sorption mechanism of Cr by chitosan was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the chitosan, the surface morphology of the biomass was determined by SEM （scanning electron microscope） and specific surface area analyzer （N2-BET （Brunaeur, Emmet and Teller））. Consequently, the following matters have been mainly clarified： （1） chitosan can be an efficient sorbent for Cr （both Cr（Ⅲ） and Cr（Ⅵ））; （2） the effect of common ions on the adsorption ofCr （Cr（Ⅲ） and Cr（Ⅵ）） was not significant under this experimental conditions; （3） adsorption isotherms using the chitosan can be generally described by Langmuir isotherm more satisfactorily for Cr. The adsorption may have occurred mainly by monolayer reaction; （4） the rates of adsorption were found to conform to pseudo-second order kinetics.
文摘This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr（Ⅵ） using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr（Ⅵ） adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry） in order to determine the optimum conditions for Cr（Ⅵ） adsorption. Furthermore, the adsorption mechanism of Cr（Ⅵ） by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.
基金Supported by the National Key Basic Research Development Plan(No.2013CB632602)the National Natural Science Foundation of China(No.21306198)
文摘In this study, quaternized chitosan microspheres （QCMS） were prepared and its Cr （VI） removal potential was investigated. Batch experiments were conducted to examine kinetics, adsorption isotherm, pH effect, and thermodynamic parameters. Equilibrium was attained within 50 rain and maximum removal of 97.34% was achieved under the optimum conditions at pH 5. Adsorption data for Cr （VI） uptake by the QCMS were analyzed according to Langmuir, Freundlich, and Temkin adsorption models. The maximum uptake of Cr （VI） was 39.1 mg.g-a. Thermodynamic parameters for the adsorption system were determinated at 293 K, 303 K, 313 K and 323 K. （AH° = 16.08 kJ.mol- 1;AG° = -5.84 to -8.08 kJ.mo1-1 and AS° = 74.81 J.K-1 .tool-l）. So the positive values of both A/-F and AS° suggest an endothermic reaction and increase in randomness at the solid-liquid interface during the adsorption. AG° values obtained were negative indicating a spontaneous adsorp- tion process. The kinetic process was described by a pseudo-second-order rate equation very well. The results of the present study indicated that the QCMS could he considered as a potential adsorbent for Cr （V1） in aqueous solutions.
文摘Poly(styrene-glycidyl methacrylate) particles having bowl-shaped hollow structures were synthesized by swollen seed emulsion polymerization. The PS emulsion synthesized through soap-free emulsion polymerization was swollen by toluene, and then the mixture of second monomers was added under polymerization condition. So a thin shell of poly(styrene-glycidyl methacrylate) cross-linked by triethylene glycol diacrylate was formed around the swollen PS particle. The bowl-shaped particles were obtained after the collapsing of the thin shell when the toluene emanated from the particles, but the shapes were effected by the degrees of cross-linking. The shape of the particles was observed by SEM. The release behavior of solvent from the particles was examined by TG.
基金supported by the research grants from the National 973 Project (S2009061009)the National Natural Science Foundation of China(50973038)
文摘Porous chitosan（CS）/magnetic（Fe304）/ferric hydroxide（Fe（OH）3） microsphere as novel and low-cost adsorbents for the removal of As（Ill） have been synthesized via the electrospraying technology by a simple process of two steps. Characterization of the obtained adsorbents was studied by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. The adsorption kinetics and equilibrium isotherms were in- vestigated in batch experiments. The Langmuir, Freundlich isotherm and pseudo-second order kinetic models agree well with the experimental data. The adsorption of As（III） onto CS/Fe3OdFe（OH）3 microspheres occurred rapidly and reached adsorption equilibrium after about 45 min. The maximum adsorption capacity of CS/Fe3OJFe（OH）3 microspheres, calculated by the Langmuir isotherm model, was 8.47 mg g 1, which is higher than that of CS/Fe304/Fe（OH）3 prepared by the conventional method （4.72 mg g-l）. The results showed that the microspheres had a high adsorption capacity for As（III） and a high separation efficiency due to their microporous structure and superparamagnetic characteristics. Present research may eventually lead to a simple and low cost method for fabricating microporous materials and application for removal of arsenic from aqueous solution.
基金Project supported by the Major Science and Technology Special Project (priority subject) of Zhejiang Province (No. 2008C12005-1)the Key Project of Education Department of Zhejiang Province (No. 20070147), China
文摘Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% （w/v） chitosan solutions at 15 ℃ on the growth and physiological changes were investigated using two maize （Zea rnays L.） inbred lines, HuangC （chilling-tolerant） and Mo17 （chilling-sensitive）. While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time （MGT）, and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde （MDA） content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase （POD） activity, and catalase （CAT） activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60-64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.
基金financially supported by the National Natural Science Foundation of China(51343008)
文摘The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis(TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction(WAXD) and scanning electron microscope(SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin.
