A field test with the traditional rotation of paddy rice/upland crop (wheat) was carried out on a paddysoil derived from red earth to elucidate the effect of organic manure on the phosphorus adsorption-desorptionby so...A field test with the traditional rotation of paddy rice/upland crop (wheat) was carried out on a paddysoil derived from red earth to elucidate the effect of organic manure on the phosphorus adsorption-desorptionby soil and its P availability Soil samples were taken from different treatments at rice harvesting stage andanalysed. The isothermal adsorption of P by the samples fitted very well with Langmuir equation, and hence,the parameters in the equation, i.e., maximum adsoaption (qm), constant related to bonding energy (k) andtheir product (k x qm) could be used as a comprehensive index to characterize the potential P adsorptivityof the soil.Organo-inorganic fertilization and organic manuring conld decrease qm and k, while mineral P appli-cation had little effect on them. The isothermal desorption of P was significantly correlated with initiallyadded and isothermally adsorbed P. Part of P added was fixed, which represented the P fixation capacityof soil, and organic manuring could obviously lower the P fixation. The content of soil available P had asignificant negative correlation with qm, k and fixed P. It is concluded that organic manure could increase theP availability of paddy soil derived from red earth by decreasing qm, k, maximum buffering capacity (MBC=k x qm) and fixation capacity.展开更多
The effect of temperature on the properties of boron adsorption-desorption in brown-red soil, yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique. Th...The effect of temperature on the properties of boron adsorption-desorption in brown-red soil, yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique. The experimental data of B adsorption-desorption amounts and reaction t line at 25 and 40℃ were fitted by the zero-order, first-order and parabolic diffusion kinetic equations. The adsorption process was in conformity with the parabolic diffusion law at both the temperatures, and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138, 0.124 and 0.105 mg kg-1 min-1/2 at 25℃, and 0.147, 0.146 and 0.135 mg kg-1 min-1/2 at 40℃ for the brown-red soil, yellow-brown soil, and calcareous alluvial soil, respectively. The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation, and the corresponding values of rate constant were 0.0422, 0.0563 and 0.0384 min-1 at 25℃, and 0.0408, 0.042 3 and 0.0401 min-1 at 40℃ for the brown-red soil, the yellow-brown soil and the calcareous alluvial soil, respectively. Therefore, the desorption process of B might be related to the amount of B adsorbed in soil. The higher the temperature, the lower the amount of B adsorption for the same soil in the same reaction time. The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27, 8.44 and 12.99 kJ mol-1, respectively, based on the experimental data of B adsorption amounts and reaction time at 25 and 40℃.展开更多
The adsorption properties of phenol on XDA-1 resin were studied by chemical analysis and IR spectrometry.The statically saturated adsorption capacity,dynamic saturated adsorption capacity,apparent activation energy,th...The adsorption properties of phenol on XDA-1 resin were studied by chemical analysis and IR spectrometry.The statically saturated adsorption capacity,dynamic saturated adsorption capacity,apparent activation energy,thermodynamic parameters,and adsorption rate constants were measured at different temperatures.As a result,adsorption of phenol on the resin obeys the Freundlich formula.And phenol was recovered quantitatively when ethanol,acetone or 1.0 mol/L sodium hydroxide were used to desorb it from the column.展开更多
文摘A field test with the traditional rotation of paddy rice/upland crop (wheat) was carried out on a paddysoil derived from red earth to elucidate the effect of organic manure on the phosphorus adsorption-desorptionby soil and its P availability Soil samples were taken from different treatments at rice harvesting stage andanalysed. The isothermal adsorption of P by the samples fitted very well with Langmuir equation, and hence,the parameters in the equation, i.e., maximum adsoaption (qm), constant related to bonding energy (k) andtheir product (k x qm) could be used as a comprehensive index to characterize the potential P adsorptivityof the soil.Organo-inorganic fertilization and organic manuring conld decrease qm and k, while mineral P appli-cation had little effect on them. The isothermal desorption of P was significantly correlated with initiallyadded and isothermally adsorbed P. Part of P added was fixed, which represented the P fixation capacityof soil, and organic manuring could obviously lower the P fixation. The content of soil available P had asignificant negative correlation with qm, k and fixed P. It is concluded that organic manure could increase theP availability of paddy soil derived from red earth by decreasing qm, k, maximum buffering capacity (MBC=k x qm) and fixation capacity.
文摘The effect of temperature on the properties of boron adsorption-desorption in brown-red soil, yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique. The experimental data of B adsorption-desorption amounts and reaction t line at 25 and 40℃ were fitted by the zero-order, first-order and parabolic diffusion kinetic equations. The adsorption process was in conformity with the parabolic diffusion law at both the temperatures, and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138, 0.124 and 0.105 mg kg-1 min-1/2 at 25℃, and 0.147, 0.146 and 0.135 mg kg-1 min-1/2 at 40℃ for the brown-red soil, yellow-brown soil, and calcareous alluvial soil, respectively. The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation, and the corresponding values of rate constant were 0.0422, 0.0563 and 0.0384 min-1 at 25℃, and 0.0408, 0.042 3 and 0.0401 min-1 at 40℃ for the brown-red soil, the yellow-brown soil and the calcareous alluvial soil, respectively. Therefore, the desorption process of B might be related to the amount of B adsorbed in soil. The higher the temperature, the lower the amount of B adsorption for the same soil in the same reaction time. The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27, 8.44 and 12.99 kJ mol-1, respectively, based on the experimental data of B adsorption amounts and reaction time at 25 and 40℃.
基金Natural Science Foundation of Zhejiang Province of China(No.Y3090531)
文摘The adsorption properties of phenol on XDA-1 resin were studied by chemical analysis and IR spectrometry.The statically saturated adsorption capacity,dynamic saturated adsorption capacity,apparent activation energy,thermodynamic parameters,and adsorption rate constants were measured at different temperatures.As a result,adsorption of phenol on the resin obeys the Freundlich formula.And phenol was recovered quantitatively when ethanol,acetone or 1.0 mol/L sodium hydroxide were used to desorb it from the column.
