The diffusion coefficients of aqueous L-threonine solutions were determined from 298.15 K to 328.15 K by the metallic diaphragm cell method with accuracy, promptness and convenience. Meanwhile, the densities and visco...The diffusion coefficients of aqueous L-threonine solutions were determined from 298.15 K to 328.15 K by the metallic diaphragm cell method with accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined and correlated. Based on a semi-empirical model for correlating the diffusion coefficients of some amino acids in their aqueous solutions, a new semi-empirical model for correlating the diffusion coefficients involving temperature was provided, which is more comprehensive and less experiment dependent compared to the previous model. The fitting results are satisfactory. Compared to a former model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions, this model provides significant improvement in correlation of diffusion coefficients with different temperatures avoiding arduous work.展开更多
In this work, mass transfer mechanism was studied for 50%TBP (in kerosene)-phenol-water as the working system in different hydrophobic microporous hollow fiber modules. The effect of different operating conditions on ...In this work, mass transfer mechanism was studied for 50%TBP (in kerosene)-phenol-water as the working system in different hydrophobic microporous hollow fiber modules. The effect of different operating conditions on the removal of phenol was analyzed. Solvent entrainment in this process was detected with MALVERN-2600 laser pellet diameter analytical equipment. Experimental results indicate the mass transfer coefficient is increased while the two phase flow rates are increased. With increases in the flow rate of the water phase, the removal ratio of phenol will be decreased. Highly effective removal of phenol could be reached by changing the experimental conditions and the module configuration. The solvent entrainment in the water phase in the membrane extraction process was found to be 5%—8% of that in conventional liquid-liquid extraction process. Thus, solvent pollution could be better controlled.展开更多
Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol fr...Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol from wastewater and obtain valuable phenolic compound.One of potential method is extraction using green based liquid organic solvent.Therefore,the feasibility of using palm oil was investigated.In this research,palm oil based organic phase was used as diluents to treat a simulated wastewater containing 300×10^(-6) of phenol solution using emulsion liquid membrane process(ELM).The stability of water-in-oil(W/O) emulsion on diluent composition and the parameters affecting the phenol removal efficiency and stability of the emulsion;such as emulsification speed,emulsification time,agitation speed,surfactant concentration,pH of external phase,contact time,stripping agent concentration and treat ratio were carried out.The results of ELM study showed that at ratio7 to 3 of palm oil to kerosene,5 min and 1300 r·min^(-1) of emulsification process the stabile primary emulsion were formed.Also,no carrier is needed to facilitate the phenol extraction.In experimental conditions of500 r·min^(-1) of agitation speed,3%Span 80,pH 8 of external phase,5 min of contact time,0.1 mol·L^(-1) NaOH as stripping agent and 1:10 of treat ratio,the ELM process was very promising for removing the phenol from the wastewater.The extraction performance at about 83%of phenol was removed for simulated wastewater and an enrichment of phenol in recovery phase as phenolate compound was around 11 times.展开更多
基金Supported by the Educational Ministry Doctor Foundation of China (No. 2000005608).
文摘The diffusion coefficients of aqueous L-threonine solutions were determined from 298.15 K to 328.15 K by the metallic diaphragm cell method with accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined and correlated. Based on a semi-empirical model for correlating the diffusion coefficients of some amino acids in their aqueous solutions, a new semi-empirical model for correlating the diffusion coefficients involving temperature was provided, which is more comprehensive and less experiment dependent compared to the previous model. The fitting results are satisfactory. Compared to a former model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions, this model provides significant improvement in correlation of diffusion coefficients with different temperatures avoiding arduous work.
基金Supported by the National Natural Science Foundation of China.
文摘In this work, mass transfer mechanism was studied for 50%TBP (in kerosene)-phenol-water as the working system in different hydrophobic microporous hollow fiber modules. The effect of different operating conditions on the removal of phenol was analyzed. Solvent entrainment in this process was detected with MALVERN-2600 laser pellet diameter analytical equipment. Experimental results indicate the mass transfer coefficient is increased while the two phase flow rates are increased. With increases in the flow rate of the water phase, the removal ratio of phenol will be decreased. Highly effective removal of phenol could be reached by changing the experimental conditions and the module configuration. The solvent entrainment in the water phase in the membrane extraction process was found to be 5%—8% of that in conventional liquid-liquid extraction process. Thus, solvent pollution could be better controlled.
基金Supported by the Ministry of Higher Education(MOHE)Universiti Teknologi Malaysia(RU Research GrantGUP:Q.J130000.2546.12H50)
文摘Phenol is considered as pollutant due to its toxicity and carcinogenic effect.Thus,variety of innovative methods for separation and recovery of phenolic compounds is developed in order to remove the unwanted phenol from wastewater and obtain valuable phenolic compound.One of potential method is extraction using green based liquid organic solvent.Therefore,the feasibility of using palm oil was investigated.In this research,palm oil based organic phase was used as diluents to treat a simulated wastewater containing 300×10^(-6) of phenol solution using emulsion liquid membrane process(ELM).The stability of water-in-oil(W/O) emulsion on diluent composition and the parameters affecting the phenol removal efficiency and stability of the emulsion;such as emulsification speed,emulsification time,agitation speed,surfactant concentration,pH of external phase,contact time,stripping agent concentration and treat ratio were carried out.The results of ELM study showed that at ratio7 to 3 of palm oil to kerosene,5 min and 1300 r·min^(-1) of emulsification process the stabile primary emulsion were formed.Also,no carrier is needed to facilitate the phenol extraction.In experimental conditions of500 r·min^(-1) of agitation speed,3%Span 80,pH 8 of external phase,5 min of contact time,0.1 mol·L^(-1) NaOH as stripping agent and 1:10 of treat ratio,the ELM process was very promising for removing the phenol from the wastewater.The extraction performance at about 83%of phenol was removed for simulated wastewater and an enrichment of phenol in recovery phase as phenolate compound was around 11 times.
