The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thi...The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thistle seeds increased with the microwave output power and temperature during MAE processing. The apparent extraction rate constant k （s-1） was 1.2028×10-2 , 1.2248×10-2 , and 1.2485×10-2 , and diffusion coefficient D （m2·s-1 ） was 4.21×10-10, 4.29×10-10 , and 4.37×10-10 at the microwave temperatures of 383, 393, and 403 K, respectively, in the silymarin MAE process. With the help of scanning electron microscopy （SEM）, the microstructures of the samples extracted by MAE were observed. The results revealed that the increased efficiency and rate of MAE of silymarin could be attributed mainly to the subsequent cell change resulting from superheating effects during MAE.展开更多
Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-s...Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant（kobs） significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus（TRP） was established with kobs=（3.51 ± 0.11） × 10^-4× TRP. Finally, it was suggested that the Langmuir–Rideal（L–R）or Langmuir–Hinshelwood（L–H） mechanism may be used to describe the removal process of phosphorus using BOF-slag.展开更多
基金Supported by the National Natural Science Foundation of China(31071579)the Key Program of the Natural Science Foundation of Heilongjiang Province of China(ZD201013)the Key Project of Education Department of Heilongjiang Province of China(125212003)
文摘The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thistle seeds increased with the microwave output power and temperature during MAE processing. The apparent extraction rate constant k （s-1） was 1.2028×10-2 , 1.2248×10-2 , and 1.2485×10-2 , and diffusion coefficient D （m2·s-1 ） was 4.21×10-10, 4.29×10-10 , and 4.37×10-10 at the microwave temperatures of 383, 393, and 403 K, respectively, in the silymarin MAE process. With the help of scanning electron microscopy （SEM）, the microstructures of the samples extracted by MAE were observed. The results revealed that the increased efficiency and rate of MAE of silymarin could be attributed mainly to the subsequent cell change resulting from superheating effects during MAE.
基金financially supported by the Fundamental Research Fund for the Central Universities (No. N130302004)the National Natural Science Foundation of China (No. U1360204)
文摘Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant（kobs） significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus（TRP） was established with kobs=（3.51 ± 0.11） × 10^-4× TRP. Finally, it was suggested that the Langmuir–Rideal（L–R）or Langmuir–Hinshelwood（L–H） mechanism may be used to describe the removal process of phosphorus using BOF-slag.
