In this work,the effects of degradation time,temperature,and pH value on the degradation of Salvianolic acid B in aqueous solution were determined.Higher pH values,higher extraction temperature,and longer extraction t...In this work,the effects of degradation time,temperature,and pH value on the degradation of Salvianolic acid B in aqueous solution were determined.Higher pH values,higher extraction temperature,and longer extraction time led to more degradation of Salvianolic acid B.Danshensu concentration increased as Salvianolic acid B degraded.A mechanism model was developed considering the degradation of Salvianolic acid E and lithospermic acid,which were two degradation products of Salvianolic acid B.The reverse reactions of Salvianolic acid B degradation were also considered.Degradation kinetic constants were calibrated.The degradation kinetics of Salvianolic acid B,lithospermic acid,and Danshensu in a Salvia miltiorrhiza extract aqueous solution were predicted using the mechanism model.The predicted concentrations agreed well with the experimental results.This model was developed using degradation data obtained from simple composition systems,but it can be applied in a complex botanical mixture with high prediction accuracy.展开更多
This paper discusses such models for the degradation kinetics of pesticides in soil as the model expressingthe degradation rate as a function of two variables: the pesticide concentration and the number of pesticide-d...This paper discusses such models for the degradation kinetics of pesticides in soil as the model expressingthe degradation rate as a function of two variables: the pesticide concentration and the number of pesticide-degrading microorganisms, the model expressing the pesticide concentration as an explicit or implicit functionof time, and the model expressing the pesticide loss rate constants as functions of temperature. These modelsmay interpret the degradation curves with an inflection point . A kinetic model describing the growth processesof microbial populations in a closed system is reported as well.展开更多
A set of equations is suggested to describe the kinetics of degradation of organic compounds applied tosoils and the kinetics of growth of the involved microorganisme:where x is the concentration of organic compound a...A set of equations is suggested to describe the kinetics of degradation of organic compounds applied tosoils and the kinetics of growth of the involved microorganisme:where x is the concentration of organic compound at time t, m is the number of forcroorganisms capableof degrading the organic compound at time t, while j, k, f and g are positive constaats. This model cansatisfactorily be used to explain the degradation curve of organic compounds and the growth curve of theinvolved microorganisms.展开更多
Biodegradation parameters and kinetic characteristics for pre-treating waste strains of Klebsiella pneu-moniae were studied in laboratory scale with an insulated reactor by an innovative technique,autothermal thermo-p...Biodegradation parameters and kinetic characteristics for pre-treating waste strains of Klebsiella pneu-moniae were studied in laboratory scale with an insulated reactor by an innovative technique,autothermal thermo-philic aerobic digestion(ATAD) . Based on an Arrhenius-type equation,an empirical model was developed to corre-late the removal of total suspended solid(TSS) with the initial TSS concentration,influent reaction temperature,aeration rate and stirring rate. The reaction temperatures of the ATAD system could be raised from the ambient temperatures of 25 °C to a maximum temperature of 65 °C. The exponentials for the initial TSS concentration,aeration rate and stirring rate were 1.579,-0.8175 and-0.6549,respectively,and the apparent activation energy was 6.8774 kJ·mol-1. The correlation coefficient for the pre-exponential factor was 0.9223. The TSS removal effi-ciency predicted by the model was validated with an actual test,showing a maximum relative deviation of 10.79%. The new model has a good practicability.展开更多
Co60 gamma ray radiolysis of aqueous oxalic acid solution （1 × 10-2 M） was investigated within the dose range up to 80 kGy. The value of pH increases from 2.0 to 4.0 and approximately 90% of oxalic acid and its...Co60 gamma ray radiolysis of aqueous oxalic acid solution （1 × 10-2 M） was investigated within the dose range up to 80 kGy. The value of pH increases from 2.0 to 4.0 and approximately 90% of oxalic acid and its derivatives are degraded at the dose of 80 kGy. Dissolved O2 affects to the degradation of oxalic acid at the initial stage due to total consumption of O2 at the dose of 2 kGy. Formation of CO2 occurs at a higher rate at the initial stage until the dissolved 02 is fully consumed. The kinetic model of oxalic acid degradation in aqueous solution under the gamma irradiation was tested. The suggested mechanism complies with the experimental data both of our own and of that reported earlier.展开更多
基金Supported by the National Natural Science Foundation of China(No.81273992)the Public Service Technology Research and Social Development Project of Science Technology Department of Zhejiang Province of China(2015C33128)
文摘In this work,the effects of degradation time,temperature,and pH value on the degradation of Salvianolic acid B in aqueous solution were determined.Higher pH values,higher extraction temperature,and longer extraction time led to more degradation of Salvianolic acid B.Danshensu concentration increased as Salvianolic acid B degraded.A mechanism model was developed considering the degradation of Salvianolic acid E and lithospermic acid,which were two degradation products of Salvianolic acid B.The reverse reactions of Salvianolic acid B degradation were also considered.Degradation kinetic constants were calibrated.The degradation kinetics of Salvianolic acid B,lithospermic acid,and Danshensu in a Salvia miltiorrhiza extract aqueous solution were predicted using the mechanism model.The predicted concentrations agreed well with the experimental results.This model was developed using degradation data obtained from simple composition systems,but it can be applied in a complex botanical mixture with high prediction accuracy.
文摘This paper discusses such models for the degradation kinetics of pesticides in soil as the model expressingthe degradation rate as a function of two variables: the pesticide concentration and the number of pesticide-degrading microorganisms, the model expressing the pesticide concentration as an explicit or implicit functionof time, and the model expressing the pesticide loss rate constants as functions of temperature. These modelsmay interpret the degradation curves with an inflection point . A kinetic model describing the growth processesof microbial populations in a closed system is reported as well.
文摘A set of equations is suggested to describe the kinetics of degradation of organic compounds applied tosoils and the kinetics of growth of the involved microorganisme:where x is the concentration of organic compound at time t, m is the number of forcroorganisms capableof degrading the organic compound at time t, while j, k, f and g are positive constaats. This model cansatisfactorily be used to explain the degradation curve of organic compounds and the growth curve of theinvolved microorganisms.
基金Supported by the Doctoral Foundation of Northeast Dianli University (BSJXM-200814)Foundations of Bureau of Jilin Province (2008424)
文摘Biodegradation parameters and kinetic characteristics for pre-treating waste strains of Klebsiella pneu-moniae were studied in laboratory scale with an insulated reactor by an innovative technique,autothermal thermo-philic aerobic digestion(ATAD) . Based on an Arrhenius-type equation,an empirical model was developed to corre-late the removal of total suspended solid(TSS) with the initial TSS concentration,influent reaction temperature,aeration rate and stirring rate. The reaction temperatures of the ATAD system could be raised from the ambient temperatures of 25 °C to a maximum temperature of 65 °C. The exponentials for the initial TSS concentration,aeration rate and stirring rate were 1.579,-0.8175 and-0.6549,respectively,and the apparent activation energy was 6.8774 kJ·mol-1. The correlation coefficient for the pre-exponential factor was 0.9223. The TSS removal effi-ciency predicted by the model was validated with an actual test,showing a maximum relative deviation of 10.79%. The new model has a good practicability.
文摘Co60 gamma ray radiolysis of aqueous oxalic acid solution （1 × 10-2 M） was investigated within the dose range up to 80 kGy. The value of pH increases from 2.0 to 4.0 and approximately 90% of oxalic acid and its derivatives are degraded at the dose of 80 kGy. Dissolved O2 affects to the degradation of oxalic acid at the initial stage due to total consumption of O2 at the dose of 2 kGy. Formation of CO2 occurs at a higher rate at the initial stage until the dissolved 02 is fully consumed. The kinetic model of oxalic acid degradation in aqueous solution under the gamma irradiation was tested. The suggested mechanism complies with the experimental data both of our own and of that reported earlier.
