The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-so...The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal performance.The ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after modification.Compared to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 nm.The cation exchange capacity(CEC)of SMMZ is higher than that of the natural zeolite.And the ammonia nitrogen removal rate is consistent with the change of CEC.The SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm model.The adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.展开更多
To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elas...To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.展开更多
Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with...Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with sodium sulphide at boil to develop affinity for cotton. Application of sulphide has generated global debate because of its eco-unfriendly technology of dyeing. In this work, attempts were made to substitute sodium sulphide with alkaline pectinase. Obtained results suggested the ability of the latter to cause effective reduction and solubilisation of sulphur dyes. Stability of reduction baths as well as colour fastness was also reported to be in line with those obtained using sodium sulphide.展开更多
The physicochemical properties,including the density,viscosity,and refractive index of aqueous solutions of sodium glycinate as a solvent for CO_2 absorption in the non-precipitation regime were measured under the wid...The physicochemical properties,including the density,viscosity,and refractive index of aqueous solutions of sodium glycinate as a solvent for CO_2 absorption in the non-precipitation regime were measured under the wide temperature range of 298.15 to 343.15 K.The concentration of the sodium glycinate in an aqueous form in the non-precipitation regime was identified up to 2.0 mol ? L^(-1).The coefficients of thermal expansion values were estimated from measured density data.It was found that,the densities,viscosities and refractive indices of the aqueous sodium glycinate decrease with an increase in temperature,whereas with increasing sodium glycinate concentration in the solution,all three properties increase.Thermal expansion coefficients slightly increase with rising temperature and concentration.The measured values of density,viscosity and refractive index were correlated as a function of temperature by using the least squares method.The predicted data obtained from correlation equations for all measured properties were in fairly good agreement with the experimental data.展开更多
Performance of simultaneous desulfurization and denitration using the solution of NaClO2 and NaClO as new-style complex absorbent was investigated experimentally in self-designed bench scale bubbling reactor. The effe...Performance of simultaneous desulfurization and denitration using the solution of NaClO2 and NaClO as new-style complex absorbent was investigated experimentally in self-designed bench scale bubbling reactor. The effects of main parameters, such as the concentrations of NaClO2 and of NaClO, solution pH and reaction temperature and so on, on removal efficiencies of SO2 and NOx, were examined, then the optimal conditions were established, in which the molar ratio of NaClO to NaClO2 was 1：1, the reaction temperature was 50℃ and the solution pH was 5.5. The removal efficiencies of SO2 and NO under the optimal conditions were 100% and 89.2%, respectively. The mechanism of simultaneous removal based on complex absorbent was proposed by analyzing the removal products and the electrode potentials of related species, namely SO2 and NO are oxi- dized by chlorite anion, hypochlorite, chlorine dioxide and chlorine contained in complex absorbent. In thermodynamic aspect, simultaneous desulfurization and denitration reactions in liquid phase can happen spontaneously and completely, and are all exothermic reactions. It was confirmed by kinetics that for simultaneous desulfurization and denitration, the reaction order and average activation energy of SO2 were 1 and 21.6 kJ·mol^-1, respectively, and those of NO were 1 and 8.2 kJ·mol^-1, respectively.展开更多
基金Project(51174017) supported by the National Natural Science Foundation of China
文摘The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal performance.The ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after modification.Compared to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 nm.The cation exchange capacity(CEC)of SMMZ is higher than that of the natural zeolite.And the ammonia nitrogen removal rate is consistent with the change of CEC.The SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm model.The adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.
基金Project(LY13E080021) supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(2011A610072) supported by the Ningbo Municipal Natural Science Foundation,ChinaProject(XKL14D2063) supported by Subject Program of Ningbo University,China
文摘To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.
文摘Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with sodium sulphide at boil to develop affinity for cotton. Application of sulphide has generated global debate because of its eco-unfriendly technology of dyeing. In this work, attempts were made to substitute sodium sulphide with alkaline pectinase. Obtained results suggested the ability of the latter to cause effective reduction and solubilisation of sulphur dyes. Stability of reduction baths as well as colour fastness was also reported to be in line with those obtained using sodium sulphide.
基金Universiti Teknologi PETRONAS for providing financial support(Grant number YUTP-15-8209-005)RCCO_2C for technical support to complete the present research work
文摘The physicochemical properties,including the density,viscosity,and refractive index of aqueous solutions of sodium glycinate as a solvent for CO_2 absorption in the non-precipitation regime were measured under the wide temperature range of 298.15 to 343.15 K.The concentration of the sodium glycinate in an aqueous form in the non-precipitation regime was identified up to 2.0 mol ? L^(-1).The coefficients of thermal expansion values were estimated from measured density data.It was found that,the densities,viscosities and refractive indices of the aqueous sodium glycinate decrease with an increase in temperature,whereas with increasing sodium glycinate concentration in the solution,all three properties increase.Thermal expansion coefficients slightly increase with rising temperature and concentration.The measured values of density,viscosity and refractive index were correlated as a function of temperature by using the least squares method.The predicted data obtained from correlation equations for all measured properties were in fairly good agreement with the experimental data.
文摘Performance of simultaneous desulfurization and denitration using the solution of NaClO2 and NaClO as new-style complex absorbent was investigated experimentally in self-designed bench scale bubbling reactor. The effects of main parameters, such as the concentrations of NaClO2 and of NaClO, solution pH and reaction temperature and so on, on removal efficiencies of SO2 and NOx, were examined, then the optimal conditions were established, in which the molar ratio of NaClO to NaClO2 was 1：1, the reaction temperature was 50℃ and the solution pH was 5.5. The removal efficiencies of SO2 and NO under the optimal conditions were 100% and 89.2%, respectively. The mechanism of simultaneous removal based on complex absorbent was proposed by analyzing the removal products and the electrode potentials of related species, namely SO2 and NO are oxi- dized by chlorite anion, hypochlorite, chlorine dioxide and chlorine contained in complex absorbent. In thermodynamic aspect, simultaneous desulfurization and denitration reactions in liquid phase can happen spontaneously and completely, and are all exothermic reactions. It was confirmed by kinetics that for simultaneous desulfurization and denitration, the reaction order and average activation energy of SO2 were 1 and 21.6 kJ·mol^-1, respectively, and those of NO were 1 and 8.2 kJ·mol^-1, respectively.
