To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Sa...To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae （CAS） was investigated.The CAS beads were characterized by Scanning electron microscope （SEM） and Fourier transformed infrared spectroscopy （FTTR）.The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu（Ⅱ） and Pb（Ⅱ） uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu（Ⅱ） and Pb（Ⅱ） ions in single-component systems with much satisfaction.The experimental adsorption data of Cu（Ⅱ） and Pb（Ⅱ） ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu（lⅡ） ions was more significantly influenced by the presence of the coexistent Pb（Ⅱ） species,while the Pb（Ⅱ） removal was affected slightly by varying the initial concentration of Cu（Ⅱ）.The CAS was successfully regenerated using 1 mol/L HNO3 solution.展开更多
Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fuse...Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fusel alcohol contents in beer is a common problem in the industry.How to control the contents of fusel alcohols in a reasonable range is of great significance for improving beer quality.After one round of ultraviolet(UV)and one round of multifunctional plasma mutagenesis system(MPMS)mutagenesis,the yeast strains with lower fusel oil yield and more stablility could be screened.According to the relationship between the fusel alcohol Harris metabolic pathway of brewer's yeast and lactic acid metabolism,excellent strains were obtained by triple screening with lactic acid medium,calcium carbonate medium and 2,3,5-triphenyl tetrazolium chloride upper medium.The content of fusel alcohol in the finished beer fermentation test of screened strain Z43 was 52.1±0.142 mg•L^(-1),which was 43%lower than that of the starting strain,and other fermentation properties remained unchanged.After eight passages,it was verified that the strain was stable and heritable.These results showed that strain Z43 presented promising characteristics for use in the production of beer with a potentially low contents of fusel alcohols.展开更多
基金Project(11JJ2031)supported by the Key Project of Natural Science Foundation of Hunan Province,China
文摘To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae （CAS） was investigated.The CAS beads were characterized by Scanning electron microscope （SEM） and Fourier transformed infrared spectroscopy （FTTR）.The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu（Ⅱ） and Pb（Ⅱ） uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu（Ⅱ） and Pb（Ⅱ） ions in single-component systems with much satisfaction.The experimental adsorption data of Cu（Ⅱ） and Pb（Ⅱ） ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu（lⅡ） ions was more significantly influenced by the presence of the coexistent Pb（Ⅱ） species,while the Pb（Ⅱ） removal was affected slightly by varying the initial concentration of Cu（Ⅱ）.The CAS was successfully regenerated using 1 mol/L HNO3 solution.
基金Supported by Heilongjiang Natural Science Foundation Joint Guide Project(LH2019C022)。
文摘Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fusel alcohol contents in beer is a common problem in the industry.How to control the contents of fusel alcohols in a reasonable range is of great significance for improving beer quality.After one round of ultraviolet(UV)and one round of multifunctional plasma mutagenesis system(MPMS)mutagenesis,the yeast strains with lower fusel oil yield and more stablility could be screened.According to the relationship between the fusel alcohol Harris metabolic pathway of brewer's yeast and lactic acid metabolism,excellent strains were obtained by triple screening with lactic acid medium,calcium carbonate medium and 2,3,5-triphenyl tetrazolium chloride upper medium.The content of fusel alcohol in the finished beer fermentation test of screened strain Z43 was 52.1±0.142 mg•L^(-1),which was 43%lower than that of the starting strain,and other fermentation properties remained unchanged.After eight passages,it was verified that the strain was stable and heritable.These results showed that strain Z43 presented promising characteristics for use in the production of beer with a potentially low contents of fusel alcohols.
