The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorptio...The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.展开更多
The potential inhibition of particulates on sonication of aqueous pollutants was investigated. Sonodegradation of bromobenzene, bromophenolate ion, and 2,4,5-trichlorobiphenyl were studied in the presence of various t...The potential inhibition of particulates on sonication of aqueous pollutants was investigated. Sonodegradation of bromobenzene, bromophenolate ion, and 2,4,5-trichlorobiphenyl were studied in the presence of various types of particulates suspended in water. Particulates of three different diameters (10 nm, 15 μm, and 35 μm) and two types (silica and polyaromatic resin) were investigated over a wide range of concentrations (0.05 g/L to 10 g/L). The results demonstrated that particulates inhibited sonication only when the target compound sorbed on the solid during sonication and could not partition into cavitation bubbles. The inhibition of the sorbed molecules was almost complete, and relatively independent of the particle concentration within certain ranges. However, the complexity of sonochemistry and particulate-solute matrices precludes a simple universal prediction of the inhibition extent.展开更多
A new model, phase equilibrium-kinetics model (PEKM), for estimation of diffusion coefficient was proposed in this paper. Kinetic experiments of phenol desorption on NKAII resin in the presence and the absence of ultr...A new model, phase equilibrium-kinetics model (PEKM), for estimation of diffusion coefficient was proposed in this paper. Kinetic experiments of phenol desorption on NKAII resin in the presence and the absence of ultrasound were separately conducted, and diffusion coefficients of phenol within an adsorbent particle were estimated by means of proposed PEKM and classic simplified model. Results show that the use of ultrasound not only changes the phase equilibrium state of NKA II resin/phenol/water system which had been equilibrium at normal condition, but also enhances diffusion of phenol within the resin. The diffusion coefficient of phenol in the resin in the field of ultrasound increases in an order of magnitude in comparison with the diffusion coefficient determined under no ultrasound. Experimental results also indicated that the diffusion coefficients estimated by PEKM were more accurate than that estimated by the classic simplified model.展开更多
基金Supported by the National lqatural Science Foundation of China （20346003）.
文摘The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.
文摘The potential inhibition of particulates on sonication of aqueous pollutants was investigated. Sonodegradation of bromobenzene, bromophenolate ion, and 2,4,5-trichlorobiphenyl were studied in the presence of various types of particulates suspended in water. Particulates of three different diameters (10 nm, 15 μm, and 35 μm) and two types (silica and polyaromatic resin) were investigated over a wide range of concentrations (0.05 g/L to 10 g/L). The results demonstrated that particulates inhibited sonication only when the target compound sorbed on the solid during sonication and could not partition into cavitation bubbles. The inhibition of the sorbed molecules was almost complete, and relatively independent of the particle concentration within certain ranges. However, the complexity of sonochemistry and particulate-solute matrices precludes a simple universal prediction of the inhibition extent.
基金The National Natural Science Foundation of China (No. 29936100) The Natural Science Foundation of Guangdong Province (No. 990629).
文摘A new model, phase equilibrium-kinetics model (PEKM), for estimation of diffusion coefficient was proposed in this paper. Kinetic experiments of phenol desorption on NKAII resin in the presence and the absence of ultrasound were separately conducted, and diffusion coefficients of phenol within an adsorbent particle were estimated by means of proposed PEKM and classic simplified model. Results show that the use of ultrasound not only changes the phase equilibrium state of NKA II resin/phenol/water system which had been equilibrium at normal condition, but also enhances diffusion of phenol within the resin. The diffusion coefficient of phenol in the resin in the field of ultrasound increases in an order of magnitude in comparison with the diffusion coefficient determined under no ultrasound. Experimental results also indicated that the diffusion coefficients estimated by PEKM were more accurate than that estimated by the classic simplified model.
